A: Difference between revisions

From Embryology
No edit summary
(Undo revision 2995 by S8600021 (Talk))
Line 1: Line 1:
{{Glossary}} | [http://embryology.med.unsw.edu.au/Notes/Index/B.htm Original B]
{{Glossary}} | [http://embryology.med.unsw.edu.au/Notes/Index/A.htm Original A]


===B-Myb===  
===AABR===  


:A protein transcription factor and a member of the A-Myb, B-Myb (MybL2) and C-Myb family found in all proliferating cells. B-Myb is the only member of this Myb family specific to embryonic stem cells and is required for both cycle progression and mitotic spindle formation. In mice, lack of the gene leads to early embryonic death, after implantation due to defects on the inner cell mass.  
:An acronym for [[#Automated_Auditory_Brainstem_Response|Automated Auditory Brainstem Response]] the neural pathway to test hearing and other brainstem pathways.


===bacteriophage===  
===abdomen===  


:(Greek, ''bakterion'' = little rod + ''phagein'' = to eat) or phage A virus that infects bacteria.
:trunk between diaphragm and pelvis.


===Balbiani body===  
===abdominal circumference===  


:(mitochondrial cloud) collection of cell organelles (mitochondria, ER, and granulofibrillar material) asymmetrically located beside the nucleus in very young oocytes in some species. Appears similar to germinal granule precursors seen some species that contain a definitive germ plasm (flies, worms, and frogs).  
:An ultrasound measurement of Abdominal Circumference (AC) is used to determine fetal age and normal development (small/large/abnormal) parameters. Measured at the outer edge of the circumference of the body plane in which the portal vein or stomach can be visualized in a tangential section. It is one of the four typical ultrasound assessments of fetal size and age: [[B#biparietal_diameter|Biparietal Diameter]] (BPD), [[H#head_circumference|Head Circumference]] (HC), Abdominal Circumference (AC), and [[F#femur_length|Femur Length]] (FL). Abdominal Circumference of less than 31 cm at 36 to 40 weeks gestation is a predictor of intrauterine growth retardation (IUGR).  


:(More? [http://www.pnas.org/cgi/content/abstract/104/1/187 PNAS - Mouse oocytes within germ cell cysts and primordial follicles contain a Balbiani body])
:(More? [http://embryology.med.unsw.edu.au/Movies/ultrasound.htm Ultrasound] | [http://embryology.med.unsw.edu.au/Notes/head.htm Head Notes] | [http://embryology.med.unsw.edu.au/Notes/../wwwhuman/Fetus.htm Fetal Notes] | [http://embryology.med.unsw.edu.au/Notes/../Child/birth1.htm Birth Notes] | [http://embryology.med.unsw.edu.au/Defect/IUGR.htm Intrauterine Growth Retardation])


===Ballottement===  
===abnormal spindle-like microcephaly-associated protein===  


:(French, ''ballottement'' = "a tossing about") Clinical palpatory test (clinical week 6 - 20) used to detect pregnancy, when the lower uterine segment (or cervix) is tapped by examiner's finger, the fetus floats upward, then sinks again and can be felt on the finger. (not considered diagnostic as it can also be elicited in the presence ovarian cysts)
:A protein concentrated at mitotic spindle poles in embryonic neuroepithelial cells (progenitor cells of the brain) and down-regulated when they switch from proliferative to neurogenic divisions. Protein is associated with determining human cerebral cortical size, possibly by maintaining symmetric cleavage plane orientation in neuroepithelial cells during brain development.  


===Bardet-Biedl syndrome===  
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://embryology.med.unsw.edu.au/Notes/neuron2.htm Neural Abnormalities] | OMIM [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=605481 ASPM] | [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&list_uids=16798874&dopt=Abstract Fish JL, Kosodo Y, Enard W, Paabo S, Huttner WB.] Aspm specifically maintains symmetric proliferative divisions of neuroepithelial cells. Proc Natl Acad Sci U S A. 2006 Jun 23)


:(BBS) is an abnormality with triallelic inheritance and is characterized by a rangne of multisystem abnormalities (cone-rod dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, neural development, male hypogonadotrophic hypogonadism, complex female genitourinary malformations, and renal dysfunction).
===abortion===


:(More? [http://embryology.med.unsw.edu.au/Notes/eye2.htm Vision Abnormalities] | [http://embryology.med.unsw.edu.au/Notes/urogen2.htm Urogenital Abnormalities] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=209900 OMIM - Bardet-Biedl syndrome] | [http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene∂=bbs#bbs GeneReviews - Bardet-Biedl syndrome])
:The premature expulsion or loss of embryo, may be induced (medical) or spontaneous (miscarriage).


===Barker Hypothesis===  
===absolute risk===  


:([[F#Fetal_Origins_Hypothesis|Fetal Origins Hypothesis]]) Term named after the researcher, Barker who began a statistical analysis in the UK, of low birth weight data (early 1900's). The hypothesis has since been renamed as the Fetal Origins Hypothesis and proposes that in utero influences can lead too permanent changes in embryo/fetus, low birth weight, which predisposes to chronic disease in adult life.  
:Term used in describing the effect of environmental teratogens on development. This epidemiological statistical term describes the high likely rate of occurrence of an abnormal phenotype among individuals exposed to the agent (e.g. fetal alcohol syndrome). The other risk descriptor term used to describe the likelyhood of an abnormality is [R.htm#relative_risk relative risk].  


:(More? [http://embryology.med.unsw.edu.au/Defect/page10.htm Fetal Origins Hypothesis Notes])
:(More? [http://embryology.med.unsw.edu.au/Defect/page1.htm#Environmental Abnormal Development - Environmental])


===Barr body===  
===AC===  


:Name given to a visible cellular feature produced by the inactivation of a single X chromosome in females.
:Acronym for [[#abdominal_circumference|Abdominal Circumference]].


===Bartholin Gland===  
===acardiac twins===  


:(= greater vestibular gland) female genital tract glands which secretes mucous. The equivalent male gland are the Bulbourethral glands.  
:(acardia, twin reversed-arterial perfusion (TRAP) sequence, chorioangiopagus parasiticus) An extreme form of twin-twin transfusion syndrome. In a twinned human fetal development where monozygotic twinning or higher multiple births have an artery-to-artery and a vein-to-vein anastomosis in the monochorial placenta. The incidence is of 1% of monochorionic twin pregnancies (1 of 35,000 pregnancies).


:(More? [http://embryology.med.unsw.edu.au/Notes/urogen.htm Urogenital Notes])
:(More? [http://embryology.med.unsw.edu.au/Defect/twin.htm Twinning] | [http://embryology.med.unsw.edu.au/Defect/twin5.htm Twin-twin transfusion syndrome] )


===basal body===  
===acaricide===  


:The base of an axoneme; a cylinder about 500 nm long that resembles a centriole; the microtubule organizing center of a cilium or a eukaryotic flagellum.
:Acarida are a subclass of the athropods, ticks and mites. Chemicals used for killing or preventing ticks and mites in crops or animals. Some of the early chemicals (eg [E.htm#endosulphan endosulphan]) may have also had a suggested endocrine disruptor function.  


===basal body temperature===
:(More? [http://embryology.med.unsw.edu.au/Notes/endocrine2.htm Endocrine Abnormalities])


:The temperature taken at its lowest point in the day, typically in the morning before getting out of bed. Note body temperature changes are used to approximately establish ovulation (increases bbt).
===accessory pancreatic duct===


:(More? [http://embryology.med.unsw.edu.au/wwwhuman/MCycle/MCycle.htm Human Menstrual Cycle] | [http://embryology.med.unsw.edu.au/Defect/hyperthermia.htm Hyperthermia])
:(APD) This duct also called Santorini‚Äôs duct may be present as an anatomical variation due to the embryological origin of the pancreas from two pancreatic buds (dorsal and ventral). Note the main pancreatic duct (MPD) from the dorsal bud, present in the body and tail of the pancreas (also called Wirsung‚Äôs duct).  


===basal ganglia===
:(More? [http://embryology.med.unsw.edu.au/Notes/endocrine10.htm Pancreas] | [http://embryology.med.unsw.edu.au/Notes/endocrine10.htm#History Pancreas History])


(basal nuclei) A central nervous system (CNS) neural structure derived embryologically from the secondary vesicle telencephalon (endbrain) and the earlier primary vesicle prosencephalon (forebrain) from the neural tube. Structurally, it connects the cerebral cortex with the thalamus and brainstem and is associated with motor control and learning.
===acheiria===


:(More? [[2009_Lecture_6|ANAT2341 Lecture - Ectoderm Development]] | [http://embryology.med.unsw.edu.au/Notes/neuron.htm|Neural Notes])
:A limb abnormality with a missing hand or foot as described in the original classical classification of limb deficiencies.  


===base===
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#limbclassification Limb Abnormalities - Classification])


:Another term for anucleotide (usually a t c g).
===achondroplasia===


:(More? [http://embryology.med.unsw.edu.au/DNA/DNA.htm DNA Notes])
:Musculoskeletal defect of short limb skeletal dysplasia, due to a mutation in a dominant gene encoding fibroblast growth factor receptor-3 (FGFR3). Most common limb dysplasia, with shortened long bones (mainly proximal long bones) and is difficult to prenatally diagnose. Other mutaions of this gene cause milder skeletal dysplasia (hypochondroplasia) and a lethal skeletal dysplasia (thanatophoric dysplasia).  


===base pair===
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus2.htm#abnormal Musculoskeletal Abnormalities] | OMIM [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=100800 Achondroplasia] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=134934 FGFR3])


:Double stranded DNA has nucleotides A-T, C-G, paired by hydrogen bonds (2 for AT, 3 for GC). Note this means that GC is harder to separate that AT.
===acrocentric===


:(More? [http://embryology.med.unsw.edu.au/DNA/DNA.htm DNA Notes])
:Term used to describe chrompsomes which pair with a centromere located very close to one end giving a "V" shape rather than "X" of a central centromere pair. In the human, chromosomes 13,14,15,21 and 22 are acrocentric. In bovine all chromosomes are acrocentric.  


===Bayley Scales of Infant Development===
:(More? [http://embryology.med.unsw.edu.au/Notes/../OtherEmb/bovine.htm Endocrine Notes])


:(BSID) A postnatal (from 1 to 42 months) neurological assessment scale used in screening and diagnosis of development using 178 item mental scale and the 111 item motor scale, the original BSID was revised in 1993 to version 2 (BSID-II). THere are several alternative assessments tests and tasks including: Alberta Infant Motor Scale (AIMS), Fagan Test of Infant Intelligence (FTII), Peabody Developmental Motor Scale II (PDMS-2) Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT), Means-End Problem-Solving Task, Operant Discrimination Learning, Mobile/Train Conjugate Reinforcement Tasks, The Transparent Barrier Detour Task, The A-not-B Task
===acrolein===


:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://embryology.med.unsw.edu.au/Child/page1.htm Postnatal Development])
:A reactive aldehyde (conjugated Type-2 alkenes) formed as a product of lipid peroxidation in biological systems. Recently identified as a cigarette-related lung cancer agent


===biliary cells===  
:(More? [http://embryology.med.unsw.edu.au/Defect/smoking.htm Abnormal Development - Smoking] | [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=17030796 PNAS Article])


:The liver epithelial cell formed from hepatoblast differentiation (hepatoblasts form from endoderm).
===Acquired Immune Deficiency Syndrome (AIDS)===


:(More? [http://embryology.med.unsw.edu.au/Notes/git7.htm Gastrointestinal Tract - Liver] | [http://embryology.med.unsw.edu.au/Notes/git.htm GIT Notes])
:A fatal disease caused by a virus (human immunodeficiency virus, HIV) that destroys the immune system's ability to fight off infection. HIV virus is capable of being transmitted from mother to fetus.  


===Billings Ovulation Method===
:(More? [http://embryology.med.unsw.edu.au/Defect/virus.htm#HIV Abnormal Development - Viral Infection])


:(BOM, Ovulation Method) A self-observation method for women use to monitor their fertility.
===acrodynia===


===biopsy===
:(Greek, ''acrodynia'' = painful extremities) chronic mercury poisoning in infants and young, also called "Pink Disease" occurred throughout the world (Australia 1890's) before the recognition of mercury's toxic effects. Mercurous chloride was used in "teething powders" which were given to crying babies as a purgative agent to cleanse the system.


:A fragment of tissue removed for (clinical/pathological/medical) study under the microscope.
:(More? [http://embryology.med.unsw.edu.au/Defect/metal.htm Heavy metals] | Michigan Health [http://www.michigan.gov/documents/mdch_MercurySpillFactsheet_85689_7.pdf MercurySpillFactsheet_85689_7.pdf])


===biotinidase===  
===acromegaly===  


:An enzyme required to free biotin from its bound form for use. Biotinidase deficiency can be detected in newborn screening and treated with daily biotin supplementation.
:Abnormality in the adult, overproduction of growth hormone causes bone thickening and cartilage growth.


===biparietal diameter===  
===acroplaxome===  


:An ultrasound measurement of Biparietal Diameter (BPD) is used to determine fetal age and normal development (small/large/abnormal) parameters. Measured as the diameter between the 2 sides of the head, used in clinical ultrasound measurements after 13 weeks (2.4 cm) to term (9.5 cm). It is one of the four typical ultrasound assessments of fetal size and age: Biparietal Diameter (BPD), [H.htm#head_circumference Head Circumference] (HC), [A.htm#abdominal_circumference Abdominal Circumference] (AC), and [F.htm#femur_length Femur Length] (FL).  
:The sperm structure which forms the acrosome plate with intermediate filament bundles of the marginal ring at the leading edge of the acrosome.  


:(More? [http://embryology.med.unsw.edu.au/Movies/ultrasound.htm Ultrasound] | [http://embryology.med.unsw.edu.au/Notes/head.htm Head Notes]) | [http://embryology.med.unsw.edu.au/wwwhuman/Fetus.htm Fetal Notes] | [http://embryology.med.unsw.edu.au/Child/birth1.htm Birth Notes])
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3b.htm Spermatogenesis] | [http://embryology.med.unsw.edu.au/Notes/week1_5.htm Fertilization])


===birth===  
===acrosin===  


:(parturition) Term describing the pysiological process of offspring (child) being born.  
:A spermatazoa acrosomal protein has a role in [F.htm#fertilization fertilization] including that of lysis of the zona pellucida (a serine protease) and in secondary zona pellucida (ZP) binding. Stored in mature spermatazoa as proacrosin.  


:(More? [http://embryology.med.unsw.edu.au/Child/birth1.htm Normal Development - Birth])  
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3b.htm Spermatogenesis] | [http://embryology.med.unsw.edu.au/Notes/week1_5.htm Fertilization] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=102480 OMIM Entry])


===birth rate===  
===acrosome===  


:A statictical term typically calculated by dividing the number of live births in a population in a year by the mid-year resident population.  
:The spermatazoa cellular structure containing a packet of enzymes located that allows it to dissolve a hole in the specialized extracellular matrix ([Z.htm#zona_pellucida zona pellucida], egg coat) surrounding the oocyte (egg). This enzymic digestion then allows the spermatazoa to penetrate and fertilize the egg. This structure is formed from the normal cellular organelle the [G.htm#golgi Golgi apparatus].  


:(More? [http://embryology.med.unsw.edu.au/Child/birth1.htm Normal Development - Birth] | [http://embryology.med.unsw.edu.au/Stats/page1.htm Statistics] | [http://embryology.med.unsw.edu.au/Stats/page2.htm Australian Statistics])  
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3b.htm Spermatogenesis] | [http://embryology.med.unsw.edu.au/Notes/week1_5.htm Fertilization])


===bladder exstrophy===  
===acrosome reaction===  


:(Greek, ''ekstriphein'' = "turn inside out") A congenital malformation with bladder open to ventral wall of abdomen (between umbilicus and pubic symphysis) and may have other anomolies associated with failure of closure of abdominal wall and bladder (epispadias, pubic bone anomolies).
:The chemical change that enables release of acrosomal contents and allow a sperm to penetrate an egg.  


:(More? [http://embryology.med.unsw.edu.au/Notes/urogenital2.htm Urogenital Abnormalities])
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3b.htm Spermatogenesis] | [http://embryology.med.unsw.edu.au/Notes/week1_5.htm Fertilization])


===blastema===  
===activin A===  


:Term used to describe an undifferentiated mass of cells.  
:(inhibin, erythroid differentiation factor) A transforming growth factor beta (TGFbeta) superfamily member which has roles in many different tissues. Acts through binding a number of activin receptors, transmembrane ser/thr kinase receptors. This protein is involved in the process of uterine endometrium development (decidualization) of human endometrial stromal cells following blastocyst implantation.  


:(More? [W.htm#Wilms_tumour Wilm's tumour])
:(More? [http://embryology.med.unsw.edu.au/Notes/week2.htm Week 2 Notes] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=147290 OMIM - inhibin])  


===blastocoel===  
===adactyly===  


:A fluid-filled cavity that exists in early development within the blastocyst. Initially the dividing cells form a solid cellular mass (morula) in which the cavity will form. In humans this cavity is present during the first and second week of development.  
:The absence of bones metacarpal or metatarsal leading to an absence of all digits as described in the original classical classification of limb deficiencies.  


:(More? [http://embryology.med.unsw.edu.au/Notes/week1_7.htm Week 1 - Blastocyst])
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#limbclassification Limb Abnormalities - Classification] | [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#handclassification Limb Abnormalities - Hand Classification])


===blastocyst===  
===ADAMTS-13===  


:(Greek, ''blastos'' = sprout + cystos = cavity) Term used to describe the hollow cellular mass that forms in early development. The blastocyst consists of cells forming an outer trophoblast layer, an inner cell mass and a fluid-filled cavity. The blastocyst inner cell mass is the source of true embryonic stem cells capable of forming all cell types within the embryo. In humans, this stage occurs in the first and second weeks after the [Z.htm#zygote zygote] forms a solid cellular mass ([M.htm#morula morula] stage) and before implantation.  
:A blood metalloprotease found in plasma which cleaves [V.htm#VWF von Willebrand factor (VWF)] in the A2 domain at the Tyr-1605‚ÄìMet-1606 bond.  


:(More? [http://embryology.med.unsw.edu.au/Notes/week1_7.htm Week 1 - Blastocyst] | [http://embryology.med.unsw.edu.au/Notes/week2.htm Week 2 Notes] | [http://embryology.med.unsw.edu.au/Notes/stemcell.htm Stem Cell Notes])
===adenine===


===blastopore===
:(adenine triphosphate) One of the 4 types ('''A'''TCG) of nucleotides that make up DNA. Base pairs with thymidine by 2 hydrogen bonds.


:The opening formed by the gastrulating cell migration in early blastula to gastrula development.
===adenohypophysis===


:(More? [http://embryology.med.unsw.edu.au/Notes/week2.htm Week 2 Notes] | [http://embryology.med.unsw.edu.au/Notes/week3.htm Week 3 Notes] | [http://embryology.med.unsw.edu.au/otheremb/frog2.htm Frog Development - Gastrulation])
:(anterior pituitary, pars distalis) The anterior part of the pituitary, which develops in the early embryo from a transient region on the roof of the pharynx called Rathke's pouch.  


===blastula===
:(More? [http://embryology.med.unsw.edu.au/Notes/endocrine7.htm Endocrine Development - Pituitary])


:(Greek, ''blastos'' = sprout = little sprout) A stage of an animal embryo that consists of a fluid-filled sphere of cells on the surface.
===adenomatous rest===


:(More? [http://embryology.med.unsw.edu.au/Notes/week2.htm Week 2 Notes])
:A kidney benign tumor developing from embryonic blastema cells. Blastema cells persist and under either genetic or epigenetic can change to become a neoplastic rest. These neoplastic rests can develop postnatally as a benign form (adenomatous rest) or a malignant [W.htm#Wilms_tumour Wilm's tumour] form. The rests are further characterised by the time of generation leading to different anatomical kidney locations: early intralobar nephrogenic rests (within the renal lobe) and late pelilobar nephrogenic rests (periphery of the renal lobe).


===blighted ovum===
:(More? [W.htm#Wilms_tumour Wilm's tumour] | [N.htm#nephrogenic_rest nephrogenic rest] | [http://embryology.med.unsw.edu.au/Notes/urogenital2.htm Urogenital Abnormalities] | [http://embryology.med.unsw.edu.au/Notes/urogenital.htm Urogenital Notes])


:(missed abortion, early fetal loss) A historic term now called replaced by ===early fetal loss===, describing embryo loss that occurs in first trimester.
===adenomyosis===  


===BLIMP1===
:(endometriosis interna, adenomyoma) A [U.htm#uterus uterus] disease involving infiltration (immediately adjacent to the endometrial cavity) of endometrial glands and stroma within the myometrium. Difficult to distinguish from [L.htm#leiomyoma leiomyoma].


:DNA-binding transcriptional repressor (zinc-finger) which has a role in both embryo development and adult tissues by regulating (repressing) p53 expression allowing normal cell growth.
:(More? [http://embryology.med.unsw.edu.au/Notes/genital2.htm Reproductive System - Abnormalities] | [http://www.nlm.nih.gov/medlineplus/ency/article/001513.htm Medlineplus - adenomyosis])  


:(More? PNAS [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=17264218 Yan J, Jiang J, Lim CA, Wu Q, Ng HH, Chin KC.] BLIMP1 regulates cell growth through repression of p53 transcription. Proc Natl Acad Sci U S A. 2007 Jan 30)
===adenovirus===  


===blood islands===
:A Class I virus containing a single double-stranded DNA (dsDNA), which can cause infections in the upper respiratory tract and gastrointestinal tract in many animals.


:The initial small patches which form within mesoderm that differentiate into both the blood vessel wall and blood cells. These islands enlarge and connect together to form the initial vascular beds.  
:(More? [http://embryology.med.unsw.edu.au/Defect/virus.htm Abnormal Development - Viral Infection])


:(More? [http://embryology.med.unsw.edu.au/Notes/heart20.htm Cardiovascular System - Blood])
===adipocyte===


===BMI===
:The mature fat cell found in fat tissue and hypodermis layer of the skin.


:Acronym for '''B'''ody '''M'''ass '''I'''ndex which is a measure of body composition. Used to determine adiposity, that is fat content, which has influences upon growth and health.
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus50.htm Musculoskeletal Development - Adipose] | [http://embryology.med.unsw.edu.au/Notes/endocrine18.htm Endocrine Development - Adipose])


===Bmi1===  
===adipogenesis===  


:A proto-oncogene protein located in the nucleus, which is a member of the Polycomb-group gene family (required to maintain the repression of homeotic genes). Expressed in range of stem cells including hematopoietic, neural and intestinal stem cells. Human BMI-1 gene on the short arm of chromosome 10 (10p13).
:The term used to describe the differentiation of preadipocytes into adipocytes.  


[http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=18536716 Sangiorgi E, Capecchi MR.] Bmi1 is expressed in vivo in intestinal stem cells. Nat Genet. 2008 Jul;40(7):915-20.
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus50.htm Musculoskeletal Development - Adipose] | [http://embryology.med.unsw.edu.au/Notes/endocrine18.htm Endocrine Development - Adipose])


:(More? [http://embryology.med.unsw.edu.au/Notes/git.htm Gastrointestinal Tract Development] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=164831 OMIM - proto-oncogene BMI-1] |
===adipose===


===BOC===
:Fat, mesodermal in origin it is a type of connective tissue consisting mainly of adipocytes. The two forms of adipose are white and brown adipose tissue. Brown adipose is found in newborns (2 - 5 % of the body weight) and can be used to dissipate stored energy as heat (thermogenesis), while adults have mainly white adipose. Adipose tissue also has an endocrine function secreting the hormones leptin, adiponectin, and resistin.


:Acronym for '''B'''rother '''o'''f '''C'''don a cell surface receptor. CDON is also a acronym for '''C'''ell adhesion molecule-regulated/'''d'''ownregulated by '''on'''cogenes. Both Boc and Cdon are cell surface receptors (for sonic hedgehog) of the immunoglobulin (Ig)/fibronectin type III that interact with each other, are coexpressed and involved in neural and muscle development.  
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus50.htm Musculoskeletal Development - Adipose] | [http://embryology.med.unsw.edu.au/Notes/endocrine18.htm Endocrine Development - Adipose])


:(More? [http://embryology.med.unsw.edu.au/Notes/MolDev/factor/shh.htm Molecular Development - sonic hedgehog] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=608708 OMIM - BROTHER OF CDON])
===adontia===


===bombesin receptor===
:Term used to describe the total lack of tooth development.


:A cell receptor family associated mainly with gastrointestinal function (motility and secretion) and neural functions (circadian rhythm, thermoregulation anxiety/fear responses, food intake). In mammals, these G protein-coupled receptors are: neuromedin B, gastrin-releasing peptide, and orphan receptor bombesin receptor subtype 3.
:(More? [http://embryology.med.unsw.edu.au/Notes/skin10.htm Integumentary Development - Tooth])


:(More? [http://embryology.med.unsw.edu.au/Notes/git.htm GIT Development] | [http://embryology.med.unsw.edu.au/Notes/endocrine.htm Endocrine Development] |)
===adnexa===


===bone===
:(Latin, ''adnexae'' = appendages) Term used to describe any anatomical appendage (accessory structure, extension or outgrowth from the body). In reproductive anatomy used to describe appendages of the [[U#uterus|uterus]] "body"; ovaries, uterine tubes and uterus supporting ligaments.


:A connective tissue forming the main structural component of the skeleton. There are two processes of bone formation (ossification): endochondrial, replacing a pre-existing cartilage template (most of the skeleton); or intramembranous, ossification directly from a membrane (cranial vault, scapula). Adult bone gross histology is described as either trabecular bone (also called cancellous or spongy bone) or compact bone (does not have any spaces or hollows).
===adrenal gland===


:(More? [http://embryology.med.unsw.edu.au/Notes/skmus9.htm Musculoskeletal Development - Bone] | [http://embryology.med.unsw.edu.au/Notes/skmus.htm Musculoskeletal Development] | [http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Bone/Bone.htm Blue Histology - Bone])
:(suprarenal gland) The endocrine organ that anatomically sits on top of the kidneys (renal). It has two different embryonic origins, neurat crest (aderenal medulla) and mesoderm (adrenal cortex).


===bone marrow===
:(More? [http://embryology.med.unsw.edu.au/Notes/endocrine9.htm Endocrine Notes - Adrenal Gland])


:The cellular components found within the core of bones, mainly long bones, which contain the adult blood stem cell population and a range of other cell types. Generally described as either red marrow (myeloid tissue) or yellow marrow (mainly fat cells.)
===adrenal virilism===


:(More? [http://embryology.med.unsw.edu.au/Notes/skmus9.htm Musculoskeletal Development - Bone] | [http://embryology.med.unsw.edu.au/Notes/skmus.htm Musculoskeletal Development])
:Abnormality that leads to the development of male secondary sexual characteristics in women with excessive adrenal gland activity.  


===bone marrow stromal cells===
:(More? [http://embryology.med.unsw.edu.au/Notes/endocrine.htm Endocrine Notes])


:(BMSCs) These are pluripotental cells from bone marrow that can potentially differentiate into a range of connective tissue and muscle cell types (cardiomyocytes, rhabdomyocytes, hepatocytes, osteocytes, chondrocytes, tencoytes, adipocytes, smooth muscle cells). These cells have therefore been seen as a source of stem cells for tissue repair.
===adventitia===


:(More? [http://embryology.med.unsw.edu.au/Notes/skmus9.htm Musculoskeletal Development - Bone] | [http://embryology.med.unsw.edu.au/Notes/skmus.htm Musculoskeletal Development])
:Anatomical term describing the outermost connective tissue covering of any organ, vessel, or other structure not covered by a serosa. The covering is from the surrounding connective tissue and does not form an integral part of such organ or structure.  


===borrelia burgdorferi===  
===AFP===  


:(''B. burgdorferi'') The agent of Lyme disease in North America and Europe. A species of bacteria of the spirochete class of the genus Borrelia.
:Acronym for [[#alpha-fetoprotein_test|Alpha-FetoProtein]] a protein detected in a prenatal diagnostic test.  


:(More? [http://embryology.med.unsw.edu.au/Defect/bacteria.htm#Lyme Abnormal Development - Bacterial Infection])  
:(More? [[#alpha-fetoprotein_test|Alpha-FetoProtein]])


===Botallo's duct===  
===aganglionic colon===  


:(ductus arteriosus) A vascular shunt between pulmonary trunk and the aortic arch. This channel degenerates to form the ligamentum arteriosum (ligamentum Botalli). In preterm infants this channel may remain open as Patent Ductus Arteriosus. Named after Leonardo Botallo an Italian surgeon in Paris (1530-1600).  
:(intestinal aganglionosis, Hirschsprung's Disease, megacolon, congenital aganglionic megacolon) see [I.htm#intestinal_aganglionosis intestinal aganglionosis]


:(More? [http://embryology.med.unsw.edu.au/Notes/heart2.htm#pda Patent Ductus Arteriosus] | [http://embryology.med.unsw.edu.au/Notes/heart2.htm#pda_image PDA Image] [http://embryology.med.unsw.edu.au/Notes/heart.htm Heart Notes] | [http://embryology.med.unsw.edu.au/Child/birth1.htm Normal Development - Birth])
:(More? [http://embryology.med.unsw.edu.au/Notes/git2.htm Gastrointestinal Tract Abnormalities] | [http://embryology.med.unsw.edu.au/Notes/ncrest2.htm Neural Crest Abnormalities])  


===bowel===  
===agglutination===  


:(intestine) Term used to describe the midgut and hindgut portion of the gastrointestinal tract running from after the stomach to the anus. Also subdivided into the small bowel (small intestine) and the large bowel (large intestine).
:Term used to describe clumping together, as of sperm, often due to infection, inflammation, or antibodies.


:(More? [http://embryology.med.unsw.edu.au/Notes/git.htm Gastrointestinal Tract Notes])
===Age-specific fertility rates===


===BPD===
:A statistical value (used by Australian Bureau of Statistics) showing the number of live births (occurred or registered) during the calendar year, according to age of mother, per 1,000 of the female estimated resident population of the same age at 30 June.


:Acronym for '''b'''i'''p'''arietal '''d'''iameter, measurement between the 2 sides of the head, used in clinical ultrasound measurements after 13 weeks.  
:(More? [http://embryology.med.unsw.edu.au/Notes/../Stats/page2.htm Australian Statistics])


:(More? [http://embryology.med.unsw.edu.au/Movies/ultrasound.htm Ultrasound Movies])
===Artificial Insemination===


===brachial plexus===
:(AI) Fertility treatment, using placement of a sperm sample inside the female reproductive tract that can be carried out by a number of different techniques: intracervical insemination, intrauterine insemination, intratubal insemination.


:(Latin, ''bracchium'' = arm) The mixed spinal nerves innervating the upper limb form a complex meshwork (crossing). :(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes])  
:(More? [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
 
===AIF===
 
:Acronym for [[#Apoptosis_Inducing_Factor|Apoptosis Inducing Factor]].
 
===alar plate===
 
:Developmental term for the dorsal region of the developing neural tube (central nervous system), derived from the lateral regions of the nerual plate. In the spinal cord, this is the sensory afferent, dorsal horn region. Nomenclature may have come from the "wing-like" appearance of this region of the folding neural plate.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | Dev Biol [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?&rid=dbio.figgrp.2898 Development of the human spinal cord])
 
===alopecia===
 
:Term used to describe the loss of hair.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/skin8.htm Integumentary Development - Hair])  
 
===alpha===
 
:Greek letter, (Α capital letter alpha; α lower case alpha) first letter of the Greek alphabet. The lower case form used in scientific literature to designate the first forms/variants of a similar protein, gene, energy form or substance.
 
:(More? [greek.htm Greek Symbols])
 
===alpha-fetoprotein===
 
:(AFP) A serum fetal glycoprotein produced by both the yolk sac and fetal liver. The presence of the protein in maternal blood is the basis of a test for genetic or developmental problems in the fetus. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly).  
 
:(More? [http://embryology.med.unsw.edu.au/Defect/AFP.htm Abnormal Development- AFP test])  


===brachiocephalic trunk===  
===alpha-fetoprotein test===  


:(Latin, ''bracchium'' = arm, ''cephalicus'' = head) The blood vessel forming the first branch of the aortic arch, arises superolaterally and splits into the right subclavian and the right common carotid arteries. :(More? [http://embryology.med.unsw.edu.au/Notes/heart.htm Cardiovascular Notes])
:(APF test) A prenatal test to measure the amount of a fetal protein in the mother's blood (or amniotic fluid). Abnormal amounts of the protein may indicate genetic or developmental problems in the fetus. Serum alpha-fetoprotein (AFP) is a fetal glycoprotein produced by the yolk sac and fetal liver. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly).  


===brain===
:(More? [http://embryology.med.unsw.edu.au/Defect/AFP.htm Abnormal Development- AFP test])


:The general term for the central nervous system (CNS) component formed initially from the cranial end of the neural tube. The remainder of the CNS is the spinal cord. The brain forms initially as 3 primary brain vesicles which later form 5 secondary brain vesicles.
===alpha methyldopa===


:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes])
:([M.htm#methyldopa methyldopa]) A central alpha agonist used to lower blood pressure. Used as an antihypertensive drug to lower blood pressure in pre-eclampsia, acting by either a direct or indirect central vasodilatory mechanism. A recent study suggests this drug may have a direct effect on placental and/or endothelial cell function in pre-eclampsia patients, altering angiogenic proteins. Drug commercial brandname (USA) "Aldomet", also available in combination with other drugs: methyldopa and chlorothiazide "Aldochlor", methyldopa and hydrochlorothiazide "Aldoril".
 
:(More? [http://embryology.med.unsw.edu.au/Notes/placenta2.htm#Pre-eclampsia Placenta Abnormalities - Pre-eclampsia] | [http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682242.html Medline Plus - Methyldopa] | Effect of antihypertensive therapy with alpha methyldopa on levels of angiogenic factors in pregnancies with hypertensive disorders. Khalil A, Muttukrishna S, Harrington K, Jauniaux E. PLoS ONE. 2008 Jul 23;3(7):e2766. [http://www.ncbi.nlm.nih.gov/pubmed/18648513 PMID: 18648513])
 
===alpha smooth muscle actin===
 
:(SMA) Muscle protein, one of the 6 mammalian actin isoforms. This actin is associated with vascular smooth muscle, but SMA can also be expressed in myofibroblasts, and is involved in cell-generated mechanical tension.
 
===alpha synuclein===
 
:A protein found in neurons. A dominantly inherited mutation in alpha-synuclein can cause Parkinson’s disease.
 
:(More? [http://cellbiology.med.unsw.edu.au/ UNSW Cell Biology])
 
===allantois===
 
:An [E.htm#extraembryonic_membrane extraembryonic membrane], endoderm in origin extension from the early hindgut, then cloaca into the connecting stalk of placental animals, connected to the superior end of developing bladder. In reptiles and birds, acts as a reservoir for wastes and mediates gas exchange. In mammals is associated/incorporated with connecting stalk/placental cord fetal-maternal interface.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/placenta.htm Placenta] | [http://embryology.med.unsw.edu.au/Notes/week2.htm Week 2 Notes] | [http://embryology.med.unsw.edu.au/Notes/git.htm Gastrointestinal Tract Notes])
 
===allosteric===
 
:(Greek ''allos'' = other , ''stereos'' = solid or three-dimensional) Term used to describe proteins (receptors, enzymes, motors) that have at least 2 sites that alter the protein properties. The '''active site''' binds the principal substrate. The '''regulatory site'''(s) bind effector molecule(s) that influence the protein's biological activity.
 
===altricial animal===
 
:Term used to describe an animal born in a helpless state, with incomplete development of sensory systems at birth. For example rats and mice are born with incomplete development of visual and auditory systems.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/../OtherEmb/Rat.htm Rat Development] | [http://embryology.med.unsw.edu.au/Notes/../OtherEmb/Mouse.htm Mouse Development] | [http://embryology.med.unsw.edu.au/Notes/../OtherEmb/EmbHome.htm Other Embryos])
 
===Alzheimer's Disease===
 
:(AD) A neurodegenerative disease associated mainly with ageing and the most common form of dementia. Involves neurons in the parts of the brain that control thought, memory and language. Histopathology is shown postmortem by extracellular beta-amyloid (Aß) fibrils plus intraneuronal tau (a microtubule associated protein) filaments. Named after Aloysius Alzheimer (1864-1915), a German psychiatrist and neuropathologist first published case of "presenile dementia".
 
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://www.nlm.nih.gov/medlineplus/alzheimersdisease.html Medline Plus - Alzheimer's Disease])
 
===amelia===
 
:Term used to describe the complete absence of a limb, as described in the original classical classification of limb deficiencies.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#limbclassification Limb Abnormalities - Classification])
 
===amenorrhea===
 
:The absence of a menstrual period, it can be either primary (not yet had a period by age 16) or secondary (regular period that has now stopped for 3 months).
 
:(More? [http://embryology.med.unsw.edu.au/Notes/../wwwhuman/MCycle/Mcycle.htm#Abnormalities Human Menstrual Cycle])
 
===Ames test===
 
:(Salmonella test) A mutagenic and carcinogenic test of environmental compounds. Exposure of a modified bacteria to the test compound and their subsequent ability to produce reverse mutations and then resume growth.
 
:(More? [http://embryology.med.unsw.edu.au/Defect/page1.htm Abnormal Development])
 
===amniocentesis===
 
:A prenatal diagnostic test involving sampling of amniotic fluid by needle aspiration for genetic analysis.
 
:(More? [http://embryology.med.unsw.edu.au/Defect/amniocentesis.htm Prenatal Diagnosis - Amniocentesis])
 
===amnioinfusion===
 
:A medical procedure in which a physiologic solution (such as normal saline) is infused into the uterine cavity to replace the amniotic fluid.
 
===amnion===
 
:An [[E#extraembryonic_membrane|extraembryonic membrane]] ectoderm and extraembryonic mesoderm in origin and forms the innermost fetal membrane, produces amniotic fluid. This fluid-filled sac initially lies above the trilaminar embryonic disc and with embryoic disc folding this sac is drawn ventrally to enclose (cover) the entire embryo, then fetus. The presence of this membane led to the description of reptiles, bird, and mammals as amniotes.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/placenta.htm Placenta Notes] | [http://embryology.med.unsw.edu.au/Notes/week2.htm Week 2 Notes])
 
===amniotic fluid===
 
:The fluid that fills amniotic cavity totally encloses and cushions the embryo. Amniotic fluid enters both the gastrointestinal and respiratory tract following rupture of the buccopharyngeal membrane. The late fetus swallows amniotic fluid.
 
===amniotic band syndrome===
 
:(amniotic bands) A relatively rare abnormality caused by damage to the amnion, producing fiber-like bands that trap periperal structures (arms, legs, fingers, or toes) reducing local blood supply in turn leading to abnormal development of those structures or regions.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#Amniotic_band_syndrome Musculoskeletal - Limb Development Abnormalities])
 
 
===amniotic epithelial cells===
 
:(AEC) Cells forming the epithelial layer of the amniotic membrane. These cells have also been used in recent stem cell therapeutic research.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#Amniotic_band_syndrome Musculoskeletal - Limb Development Abnormalities])
 
===amniotomy===
 
:A parturition (birth) medical procedure thought to speed labor, where the amniotic sac is artificially ruptured using a tool (amniohook).
 
:(More? [http://embryology.med.unsw.edu.au/Notes/../Child/birth1.htm Normal Development - Birth])
 
===aminopterin===
 
:Chemical rodenticide also studied as a chemotherapy drug for treating leukemia and other cancers. Teratogenic, not used as a rodenticide in the USA because exposure to it is associated with serious birth defect.
 
:(More? [http://embryology.med.unsw.edu.au/Defect/page1.htm Abnormal Development])
 
===amphimixis===
 
:(Greek, ''amphi'' = on both sides ; ''mixis'' = a mingling) Term used to describe fusion of male and female gametes, also used when referring to pronuclei fusion.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
 
===amphiregulin===
 
:(AREG) also called schwannoma-derived growth factor (SDGF). A heparin-binding and heparin-inhibited epidermal growth factor (EGF) family member, which stimulates fibroblast and keratinocyte proliferation. In mammary glands, under induction by estrogen, it stimulates mammary epithelium proliferation during puberty.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/skin7a.htm Integumentary Development - Mammary Glands] | [http://embryology.med.unsw.edu.au/Notes/../Child/puberty.htm Puberty] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=104640 OMIM - amphiregulin])
 
===ampulla===
 
:Term used to describe an anatomical dilation of a tube or canal lumen. Anatomical description of the opening end of the uterine tube lying above the ovary and the enlarged initial segmeny of the semicircular canals of the inner ear vestibular system.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/ear6.htm Inner Ear] | [http://embryology.med.unsw.edu.au/Notes/genitalXXuterus.htm Genital System - Female Uterus])
 
===Amyotrophic Lateral Sclerosis===
 
:(ALS, Lou Gehrig's disease) A postnatal neurological disease of the central nervous system, affecting the spinal cord motor neurons and brain. Henry Louis "Lou" Gehrig (1903-1941), was an American baseball player in the 1920s and 1930s who suffered from this disease.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://www.nlm.nih.gov/medlineplus/amyotrophiclateralsclerosis.html Medline Plus - Amyotrophic Lateral Sclerosis])
 
===anagen===
 
:The hair follicle active growth phase, hair follicle progenitors derived from the bulge interact with the mesenchymal dermal papilla cells to generate the lineages of the hair follicle (telogen phase is resting phase of hair growth cycle). ([http://embryology.med.unsw.edu.au/Notes/skin8.htm More? Integumentary Development - Hair])
 
===anaphase===
 
:(Greek, ''ana'' = up, again) A mitotic stage, paired chromatids separate and migrate to spindle poles.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_4a.htm%20 Week 1 - Mitosis] | [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
 
===anaphase A===
 
:The part of anaphase during which the chromosomes move.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_4a.htm%20 Week 1 - Mitosis] | [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
 
===anaphase B===
 
:The part of anaphase during which the poles of the spindle move apart.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_4a.htm%20 Week 1 - Mitosis] | [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
 
===anastomosis===
 
:Term used to describe the connection between two tubes. Applied to describe the connection between peripheral blood vessels without an intervening capillary bed.
 
===anacephaly===
 
:Neral developmental abnormality, incomplete development of cerebral hemispheres and cranium. Usually related to neural tube defect at the anterior (cranial) neuropore.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://embryology.med.unsw.edu.au/Notes/neuron2.htm Neural Abnormalities])
 
===androgens===
 
:The male sex hormones, eg testosterone.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/genitalXY.htm Genital System - Male])
 
===andrologist===
 
:A clinical specialist who treats male reproductive problems associated with spermatazoa.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3b.htm Week 1 - Spermatogenesis])
 
===aneuploidy===
 
:Term used to describe an abnormal number of chromosomes mainly (90%) due to chromosome malsegregation mechanisms in maternal meiosis I.
 
:(More?  [[trisomy 21]] | [http://embryology.med.unsw.edu.au/Notes/week1_4b.htm Meiosis])
 
===aneurism===
 
:(Greek, ''aneurysma'' = a widening, aneurysm) A term used to describe an abnormal widening of a vessel or anatomical tubal structure.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/heart%2019.htm Blood Vessel])
 
===angioblast===
 
:The embryonic precursor cell which will form the walls of both arteries and veins.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/heart%2019.htm Blood Vessel])
 
===angiopoietin===
 
:(ANGPT) factors of the vascular endothelial growth factor family which are involved with blood vessel development, recognised by two tyrosine kinase receptors (Tie1 and Tie2). Angiopoietin-1 and Angiopoietin-2 appear to have opposite effects acting through the same (Tie2) receptor.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/heart%2019.htm Blood Vessel] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=601667 OMIM - Angiopoietin 1] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=600221 OMIM - Tie2])
 
===Animalia===
 
:The kingdom that includes animals, heterotrophic multicellular organisms that undergo embryonic development.
 
===anlage===
 
:(German, ''anlage'' = primordium) Term used to describe a developmental structure, tissue or cells which will form a future structure.
 
===anoikis===
 
:(Greek, ''anoikis'' = "homelessness") A form of cell death that occurs when cells loose contact with the extracellular matrix (ECM).
 
===anosmia===
 
:Abnormality of having no sense of smell.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/nose.htm Smell] | [http://embryology.med.unsw.edu.au/Notes/senses.htm Sensory Notes])
 
===anovulation===
 
:The absence of ovulation, failure for an oocyte (egg) to be released from the ovary.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
 
===anterior===
 
:Anatomical term used to describe the front or ventral surface.
 
===anterior neuropore===
 
:(rostral, cephalic, or cranial neuropore) The initial "head end" or brain end opening of the neural tube before it closes (humans approximately 24 days postfertilization). The opening at the other "tail end" of teh neural tube is the [P.htm#posterior_neuropore posterior neuropore]. The anatomical location of the anterior neuropore in later brain development is the lamina terminalis, lying behind the pituitary gland. Failure of anterior neuropore to close leads to the neural tube defect (NTD) [#anacephaly anacephaly].
 
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron2.htm Neural Abnormalities] | [http://embryology.med.unsw.edu.au/Defect/page5e.htm Neural Tube Defects])
 
===anticodon===
 
:The 3 bases on a transfer RNA (tRNA) complementary to the messenger RNA (mRNA) codon.
 
===anticonvulsants===
 
:(antiepileptic drugs) A class of therapeutic drugs that are used to prevent and minimize seizures by acting on either ion channels, active transport, or membrane stabilization. In embryology they are teratogenic and increase the occurance of neural tube defects (NTDs). (Drug examples: Carbamazepine, Clonazepam, Ethosuximide, Phenobarbital, Phenytoin, Primidone, Valproic Acid)
 
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron2.htm Neural Abnormalities] | [http://embryology.med.unsw.edu.au/Defect/page5e.htm Neural Tube Defects] | [http://embryology.med.unsw.edu.au/Defect/page5c.htm Drug Use])
 
===Anti-Mullerian Hormone===
 
:(AMH, Mullerian Inhibiting Substance, MIS) A secreted factor (transforming growth factor-beta, TGF-beta superfamily) that regulates gonadal and genital tract development. Inhibits paramesonephric (Mullerian) duct development in males.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/genitalY.htm Male] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=600957 OMIM - AMH])
 
===antral follicle===
 
:(secondary follicle) Term used to describe the developmental stage of ovarian follicle development following preantral (primary) in describing the sequence (primordial, preantral, antral) of follicle development within the ovary. In humans, a number of primordial follicles will begin to develop into primary follicles, some of which will then form antral follicles (secondary), with only a single antral follicle developing into the ovulating follicle (Graafian) each menstrual cycle.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3a.htm Week 1 - Oogenesis])
 
===antrum===
 
:(Latin from Greek, ''antron'' = a cave, cavity; a nearly-closed cavity or bulge). Identified anatomically in many structures (ovarian follicle, bone, cardiac, gastric). In the ovary this refers to the follicular fluid-filled space within the follicle.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3a.htm Week 1 - Oogenesis])
 
===apgar===
 
:Non-invasive clinical test designed by Dr Virginia Apgar (1953) carried out immediately on newborn. The name is also an acronym for: ===A===ctivity (Muscle Tone), ===P===ulse, ===G===rimace (Reflex Irritability), ===A===ppearance (Skin Color), ===R===espiration. A score is given for each sign at one minute and five minutes after the birth.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/../Child/apgar.htm APGAR] | [http://embryology.med.unsw.edu.au/Notes/../News/history.htm History])
 
===aphalangia===
 
:The absence of phalanges (long bones) leading to an absent digit, finger or toe as described in the original classical classification of limb deficiencies.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#limbclassification Limb Abnormalities - Classification] | [http://embryology.med.unsw.edu.au/Notes/skmus72.htm#handclassification Limb Abnormalities - Hand Classification])
 
===apnea===
 
:Respiratory term meaning the cessation of breathing.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/respire.htm Respiratory Notes])
 
===apoptosis===
 
:(Greek, ''apo'' = away from + ''ptosis'' = fall) Programmed cell death which occurs in the development of many systems. e.g. between digits, nervous system. [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15906249&dopt=Abstract Kerr JF, Wyllie AH, Currie AR.] Apoptosis: a basic biological phenomenon with wide-ranging implications in tissue kinetics. Br J Cancer. 1972 Aug;26(4):239-57. Review.
 
:(More? [N.htm#necrosis necrosis] | [http://embryology.med.unsw.edu.au/Notes/../history/page1970.htm#apoptosis apoptosis] )
 
===Apoptosis Inducing Factor===
 
:(AIF) A mitochondrial protein associated apoptosis by initial chromatin condensation and high molecular weight DNA fragmentation.
 
===appositional growth===
 
:(Latin, ''appositus'' = to put near) Term used in describing a specific form of bone growth on a pre-existing surface or growth at the periphery (appositus, past participle of appnere, to put near).
 
===aquaeductus vestibuli===
 
:(Latin, aquaeductus vestibuli) See [[V#vestibular_aqueduct|vestibular aqueduct]], a tubular component of the inner ear.
 
===arachnoid===
 
:(Greek, ''arachne'' = spider + ''-oeides'' = form) A meshwork (spider web-like) connective tissue covering of the central nervous system, forms part of the meningial layers. Lies between tough outer duramater and fine piamater.
 
===Archaea===
 
:(Greek, ''archein'' = to begin), also called the Archaebacteria The kingdom (or "domain") of single-celled organisms that live under extreme environmental conditions and have distinctive biochemical features.
 
===Archaebacteria===
 
:(Greek, ''archein'' = to begin), also called the Archaea The kingdom (or "domain") of single-celled organisms that live under extreme environmental conditions and have distinctive biochemical features.
 
===archenteron===
 
:(Greek, ''arche'' = beginning + ''enteron'' = gut) The "primitive gut," the innermost tube of an animal embryo; lined with endoderm, it will become the digestive tract.
 
===arginine vasopressin===
 
:(vasopressin, AVP) A hypothalamus neuropeptide hormone stored in the posterior pituitary (neurohypophysis). The hormones actions include: stimulate liver glycogenolysis, contraction of vascular smooth muscle cells and kidney mesangial cells, antidiuresis in the kidney, and aggregation of platelets. Also in mouse, this hormone has been shown to promote maternal behavior.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/endocrine16.htm Endocrine Development - Hypothalamus] | [http://embryology.med.unsw.edu.au/Notes/endocrine7.htm Endocrine Development - Pituitary] | [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=600264 OMIM arginine vasopressin])
 
===arrhythmia===
 
:(= dysrhythmia) Term refers to cardiac abnormality of heartbeat either fast, slow, or irregular.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/heart.htm Heart Notes])
 
===Arnold-Chiari Malformation===
 
:A type of malformation which appears multifactorial (including inherited and acquired). Cerebellar tonsils elongate and herniate through foramen magnum into spinal canal, resulting in compression of parts of the brain and spinal cord, and disruption of cerebrospinal fluid flow. Thought to be fundamentally the same as anencephaly and spina bifida.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron2.htm Neural Abnormalities])


===breech===  
===ART===  


:A birth term where the fetal buttocks are presented first, this can also occur in different forms depending on the fetal structure presentation (complete breech, frank breech, footing breech, knee breech).  
:acronym for '''A'''ssisted '''R'''eproductive '''T'''echnology. All treatments or procedures that involve the handling of human eggs and sperm for the purpose of helping a woman become pregnant. Types of ART include in vitro fertilization, gamete intrafallopian transfer, zygote intrafallopian transfer, embryo cryopreservation, egg or embryo donation, and surrogate birth.  


:(More? [http://embryology.med.unsw.edu.au/Child/birth1.htm Normal Development - Birth] | [http://embryology.med.unsw.edu.au/Child/birth2.htm Birth Abnormalities])
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_5b.htm Week 1 - In Vitro Fertilization])


===Brek/Lmtk2===  
===ART cycle===  


:Acronym for brain-enriched kinase/lemur tyrosine kinase 2. Signaling protein member of the Aatyk family of kinases, mouse knockouts are infertile with azoospermia.  
:A process in which 1) an ART procedure is carried out, 2) a woman has undergone ovarian stimulation or monitoring with the intent of having an ART procedure, or 3) in the case of frozen embryos, embryos have been thawed with the intent of transferring them to a woman. A cycle begins when a woman begins taking fertility drugs or having her ovaries monitored.  


:(More? [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
:(More? [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])


===broad ligament===  
===ASD===  
 
:Acronym for [[#atrial_septal_defect atrial septal defect]], a developmental defect in the formation of the dividing septum between the two atria of the heart.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/heart2.htm Heart Abnormalities])
 
===asepsis===
 
:Term describing a sterile technique, without infection or contaminating microorganisms.
 
===Asherman syndrome===
 
:(uterine synechiae, intrauterine adhesions) Maternal syndrome (historic name) resulting from trauma to the gravid uterine cavity, which leads to the formation of intrauterine and/or intracervical adhesions.
 
===ASPM===
 
:Acronym for [[#abnormal_spindle-like_microcephaly-associated_protein|abnormal spindle-like microcephaly-associated protein]].


:Human female genital tract mesentery formed by a double fold of peritoneum that connects the [U.htm#uterus uterus] to the peritoneal floor and walls. Anatomically it has three parts: mesometrium (surrounding the [U.htm#uterus uterus]), mesosalpinx (surrounding the uterine tube) and mesovarium (surrounding the ovary).
===aster===


:(More? [http://embryology.med.unsw.edu.au/Notes/genitalXX.htm Genital System - Female])
:(Latin, ''aster'' = star) A star-like object visible in most dividing eukaryotic cells contains the microtubule organizing center.  


===bronchi===
===astral===  


(Latin, ''bronchos'' = windpipe) Plural of bronchus, the two subdivisions of the trachea carrying air to the lungs. Embryologically forms as an endodermal outpocket of the foregut which branch (bronchiole, subdivision of the bronchus) as they grow.  
:Having an aster and centrioles that participate in mitosis; characteristic of mitosis in animals and in nonvascular plants.  


:(More? [http://embryology.med.unsw.edu.au/Notes/respire.htm Respiratory Notes])
===astral microtubules===


===bronchiole===
:Microtubules that extend from each pole of the mitotic spindle without attaching to any other visible structure.


(Latin, ''bronchos'' = windpipe) A smaller branch subdivision of the bronchus.
===astrocyte===


:(More? [http://embryology.med.unsw.edu.au/Notes/respire.htm Respiratory Notes])
:A type of nervous system glial cell (non-neuronal), forms blood-brain barrier.  


===bronchus===
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes])


(Latin, ''bronchos'' = windpipe) The individual division of the trachea carrying air to the lungs. Embryologically forms as an endodermal outpocket of the foregut which branch as they grow (bronchiole, subdivision of the bronchus).
===ataxia===


:(More? [http://embryology.med.unsw.edu.au/Notes/respire.htm Respiratory Notes])
:(Greek, ''a'' = without + ''taxis'' = order) Refers to a lack of coordination of muscule movements. Both central and peripherial neurological disorders can generate this loss of coordination.  


===brown adipose===
:(More? [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://embryology.med.unsw.edu.au/Notes/neuron2.htm Neural Abnormalities] | [http://www.ninds.nih.gov/disorders/a_t/a-t.htm NINDS (USA) Ataxia Telangiectasia])


:(brown fat) Neonatal specialized form of adipose tissue used in mammals to generate body temperature (thermogenic organ) by non-shivering thermogenesis. Adult fat (white adipose) cannot be used in this fashion. This form of adipose tissue is also seen in animals that hibernate.
===ataxia telangiectasias===


:(More? [http://embryology.med.unsw.edu.au/Notes/skmus50.htm Musculoskeletal Development - Adipose])
:A neurodegenerative disease with no current cure resulting in death in teens or early 20's.  


===Bruce Effect===
:(More? [http://www.ninds.nih.gov/disorders/a_t/a-t.htm NINDS (USA) Ataxia Telangiectasia] | [http://embryology.med.unsw.edu.au/Notes/Neuron2.htm Neural Abnoormalities])


:Reproductive change in female mice, pheromones from a strange male can prevent embryo implantation in recently bred female.
===ataxia-telangiectasia mutated===


:(More? [http://embryology.med.unsw.edu.au/OtherEmb/mouse2.htm Mouse Development- Estrous Cycle])  
:(ATM) A protein kinase involved in early signaling of DNA damage (double-stranded DNA breaks) and initiates the signal transduction cascade at damage sites. ATM phosphorylates substrates involved in DNA repair and/or cell cycle control. See also Rad3-related (ATR) a broad spectrum DNA damage response signaling protein kinase.


===buccal===
:(More? [http://embryology.med.unsw.edu.au/Notes/../DNA/DNA.htm DNA Notes] [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=607585 OMIM - ataxia-telangiectasia mutated] | [http://www.ncbi.nlm.nih.gov/gquery/gquery.fcgi?term=ataxia-telangiectasia%20mutated Entrez - ataxia-telangiectasia mutated])


:(Latin, ''bucca'' = cheek) A term used to relate to the mouth (oral cavity).
===ataxia-telangiectasia and Rad3-related===


:(More? [http://embryology.med.unsw.edu.au/Notes/git.htm GIT Notes])
:(ATR) (= FRAP-related protein 1) A broad spectrum DNA damage response signaling protein kinase.  


===buccopharyngeal membrane===
:(More? [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=601215 OMIM - ataxia-telangiectasia and Rad3-related] | [http://www.ncbi.nlm.nih.gov/gquery/gquery.fcgi?term=ataxia-telangiectasia%20and%20Rad3-related Entrez - ataxia-telangiectasia and Rad3-related])


:(oral membrane) (Latin, ''bucca'' = cheek) A membrane which forms the external upper membrane limit (cranial end) of the early gastrointestinal tract (GIT). This membrane develops during gastrulation by ectoderm and endoderm without a middle (intervening) layer of mesoderm. The membrane lies at the floor of the ventral depression (stomadeum) where the oral cavity will open and will breakdown to form the initial "oral opening" of the gastrointestinal tract. The equivilent membrane at the lower end of the gastrointestinal tract is the [C.htm#cloacal_membrane cloacal membrane].
===atresia===


:(More? [http://embryology.med.unsw.edu.au/Notes/git.htm GIT Notes] | [http://embryology.med.unsw.edu.au/Notes/face.htm Face Notes] | [http://embryology.med.unsw.edu.au/Notes/head.htm Head Notes])
:(Greek, ''a'' = without + ''tresis'' = perforation) Term used for anatomical closing or absence of a cavity or opening that should exist. Used as an antomical, pathological and clinical term: esophageal atresia, biliary atresia, duodenal atresia, jejunal atresia, choanal atresia, vaginal atresia, urethral atresia, pulmonary atresia, bronchial atresia, tricuspid atresia.


===Bulbourethral Gland===
:(More? see [#atretic_follicle atretic follicle])


:(= Cowper's Gland) A male genital tract gland which secretes a small amount of a thick clear mucous fluid prior to ejaculation, the alkaline content apparently buffers acidity of the urethra. The equivalent female gland are Bartholin's glands.
===atretic follicle===


:(More? [http://embryology.med.unsw.edu.au/Notes/urogen.htm Urogenital Notes])
:An ovarian follicle that fails to mature and degenerates. Also called "atresia" referring to the process of degeneration of the ovarian follicle. At any one time the majority of follicles are destined not to complete maturation and degeneration can occur at any stage (from type 4-7).  


===bulbus cordis===
:(More? [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes] | [http://embryology.med.unsw.edu.au/Notes/week1_3a.htm Ovary Notes])


:A region of the early developing heart tube forming the common outflow tract.
===atrial septal defect===


Blood Pathway: sinus venosus -> atrium -> ventricle -> bulbus cordis (outflow tract)  
:(ASD) Heart defect, abnormal opening or hole in the septum between right and left atria. Normally allows left to right blood shunting, though additional cardiac abnormalities causing higher right side pressure (pulmonary stenosis or tricuspid atresia) allow right to left blood shunting.
 
:(More? [http://embryology.med.unsw.edu.au/Notes/heart2.htm Heart Abnormalities])
 
===atrioventricular junction===
 
:(AVJ) the heart (cardiac) region lying between the two atria and the two ventricles. In the mature heart the opening is closed on the left by the mitral valve (a bicuspid valve, has two distinct leaflets) and on the right by the tricuspid valve (three distinct leaflets).


:(More? [http://embryology.med.unsw.edu.au/Notes/heart.htm Heart Notes])
:(More? [http://embryology.med.unsw.edu.au/Notes/heart.htm Heart Notes])


===atrophy===
:Term describing the wasting away of tissue.
===auditory neurons===
Neurons of the auditory ganglia (cochlear ganglia) of cranial nerve 8 (CNVIII) involved with sound detection. These neurons form as part of the anterior ventromedial otocyst epithelium and migrate into the periotic mesenchyme at the anterior part of the developing otocyst. At this location they differentiate and extend dendrites towards the developing sensory epithelia and axons to connect with central brainstem targets.
:(More? [http://embryology.med.unsw.edu.au/Notes/ear6.htm Inner Ear] | [http://embryology.med.unsw.edu.au/Notes/ear.htm Hearing Notes])
===auricular hillocks ===
External ear (auricle) embryonic origin, a series of 6 external "bumps" three on each of pharyngeal arch 1 and 2.
:(More? [http://embryology.med.unsw.edu.au/Notes/ear8.htm External Ear] | [http://embryology.med.unsw.edu.au/Notes/ear.htm Hearing Notes])
===Automated Auditory Brainstem Response===
:(AABR) The basis of a neonatal hearing test that uses a stimulus delivered through earphones and detected by scalp electrodes. Computer ananalysed electrical measurement of activity through nuclei in the hearing central neural pathway.
:(More? [http://embryology.med.unsw.edu.au/Notes/../Child/neonatalscreening.htm#Hearing Child Notes - Neonatal Hearing Screening])
===autonomic nervous system===
:Involuntary nervous system; coordinates the responses of smooth muscles, cardiac muscles, and other effector organs including those of the endocrine, digestive, excretory, respiratory, and cardiovascular systems.
:(More? [http://embryology.med.unsw.edu.au/Notes/ncrest.htm Neural Crest Notes])
===autosomal===
:The term decribing all the chromosomes that contribute to a cell's genetic material, except for the sex chromosomes X, Y.
:(More? [http://embryology.med.unsw.edu.au/Notes/../DNA/DNA.htm DNA Notes])
===autosomal inheritance===
:Some hereditary diseases are described as autosomal which means that the disease is due to a DNA error in one of the 22 pairs that are not sex chromosomes. Both boys and girls can then inherit this error. If the error is in a sex chromosome, the inheritance is said to be sex-linked.
:(More? [http://embryology.med.unsw.edu.au/Notes/../DNA/DNA.htm DNA Notes])
===autotroph===
:(Greek, ''autos'' = self + ''trophos'' = feeder) An organism that makes its own organic molecules from simple inorganic compounds (like carbon dioxide water and ammonia).
===alveolar===
:(Latin, ''alveus'' = cavity or hollow) Term used in relation to the alveoli of the lungs. The final functional sac of the respiratory tree where gas exchange occurs between the alveolar space and the pulmonary capillaries.
:(More? [respire.htm Respiratory Notes])
===alveolar stage===
:(Latin, ''alveus'' = cavity or hollow) (aveolar phase) Term used to describe lung development, the final histological/developmental stage (Pseudoglandular, Fetal Canalicular, Terminal sac, '''Alveolar'''). This stage occurs from late fetal/neonate. The final functional sac of the respiratory tree exists, where gas exchange occurs between the alveolar space and the pulmonary capillaries.
:(More? [http://embryology.med.unsw.edu.au/Notes/respire.htm Respiratory Notes])
===alveoli===
:(Latin, ''alveus'' = cavity or hollow) The final functional sac of the respiratory tree where gas exchange occurs between the alveolar space and the pulmonary capillaries.
:(More? [respire.htm Respiratory Notes])
===auditory tube===
:(eustacian tube, otopharyngeal tube, pharyngotympanic tube) A narrow canal connecting the middle ear space to the back of the oral cavity. The tube allows ventilation protection and clearance for the middle ear cavity. Ventilation is the pressure equalization in the middle ear. Clearance is to allow fluid drainage from the middle ear. Embryonic origin is from the first pharyngeal pouch. In development, the canal is initially both horizontal, short and very narrow leading to poor drainage and easy blockage.
:(More? [http://embryology.med.unsw.edu.au/Notes/ear7.htm Middle Ear] | [http://embryology.med.unsw.edu.au/Notes/ear.htm Hearing Notes] | [http://embryology.med.unsw.edu.au/Notes/ear2.htm Abnormal Hearing Notes])
===axial mesoderm===
:Alternative name for the [N.htm#notochord notochord], an early embryonic structure lying in the midline of mesoderm within the early trilaminar embryo.
:(More? [N.htm#notochord notochord] | [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://embryology.med.unsw.edu.au/Notes/week3.htm Week 3 Notes])
===axial process===
:The precursor to the notochord. In the early embryo (week 3) epiblast structure extending from the primitive node (Hensens node) crainally, which will eventuall differentiate to for the [[N#notochord|notochord], the mesoderm structure that later replaces the axial process.
:(More? [[N#notochord|notochord]] | [http://embryology.med.unsw.edu.au/Notes/neuron.htm Neural Notes] | [http://embryology.med.unsw.edu.au/Notes/week3.htm Week 3 Notes])
===axoneme===
:The basic structure in cilia and eukaryotic flagella; consists of parallel microtubules in a characteristic "9 + 2 pattern".
:(More? [http://embryology.med.unsw.edu.au/Notes/week1.htm Week 1 Notes])
===AZF regions===
:regions on the long arm of Y chromosome (AZFa, b, and c) deletions of which result in severe damage to spermatogenesis with azoospermia or severe oligozoospermia.
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3b.htm Week 1 - Spermatogenesis] | [http://embryology.med.unsw.edu.au/Notes/week1_2.htm Week 1 Abnormalities])
===azoospermia===
:Term describing the absence of spermatazoa, a male reproductive abnormality.
:(More? [http://embryology.med.unsw.edu.au/Notes/week1_3b.htm Week 1 - Spermatogenesis] | [http://embryology.med.unsw.edu.au/Notes/week1_2.htm Week 1 Abnormalities])


{{Glossary comment}}
{{Glossary comment}}
{{Glossary}}
{{Glossary}}
{{Footer}}
{{Footer}}
[[Category:Glossary]]
[[Category:Glossary]]
[[Category:Glossary]]

Revision as of 18:24, 14 August 2009

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link | Original A

AABR

An acronym for Automated Auditory Brainstem Response the neural pathway to test hearing and other brainstem pathways.

abdomen

trunk between diaphragm and pelvis.

abdominal circumference

An ultrasound measurement of Abdominal Circumference (AC) is used to determine fetal age and normal development (small/large/abnormal) parameters. Measured at the outer edge of the circumference of the body plane in which the portal vein or stomach can be visualized in a tangential section. It is one of the four typical ultrasound assessments of fetal size and age: Biparietal Diameter (BPD), Head Circumference (HC), Abdominal Circumference (AC), and Femur Length (FL). Abdominal Circumference of less than 31 cm at 36 to 40 weeks gestation is a predictor of intrauterine growth retardation (IUGR).
(More? Ultrasound | Head Notes | Fetal Notes | Birth Notes | Intrauterine Growth Retardation)

abnormal spindle-like microcephaly-associated protein

A protein concentrated at mitotic spindle poles in embryonic neuroepithelial cells (progenitor cells of the brain) and down-regulated when they switch from proliferative to neurogenic divisions. Protein is associated with determining human cerebral cortical size, possibly by maintaining symmetric cleavage plane orientation in neuroepithelial cells during brain development.
(More? Neural Notes | Neural Abnormalities | OMIM ASPM | Fish JL, Kosodo Y, Enard W, Paabo S, Huttner WB. Aspm specifically maintains symmetric proliferative divisions of neuroepithelial cells. Proc Natl Acad Sci U S A. 2006 Jun 23)

abortion

The premature expulsion or loss of embryo, may be induced (medical) or spontaneous (miscarriage).

absolute risk

Term used in describing the effect of environmental teratogens on development. This epidemiological statistical term describes the high likely rate of occurrence of an abnormal phenotype among individuals exposed to the agent (e.g. fetal alcohol syndrome). The other risk descriptor term used to describe the likelyhood of an abnormality is [R.htm#relative_risk relative risk].
(More? Abnormal Development - Environmental)

AC

Acronym for Abdominal Circumference.

acardiac twins

(acardia, twin reversed-arterial perfusion (TRAP) sequence, chorioangiopagus parasiticus) An extreme form of twin-twin transfusion syndrome. In a twinned human fetal development where monozygotic twinning or higher multiple births have an artery-to-artery and a vein-to-vein anastomosis in the monochorial placenta. The incidence is of 1% of monochorionic twin pregnancies (1 of 35,000 pregnancies).
(More? Twinning | Twin-twin transfusion syndrome )

acaricide

Acarida are a subclass of the athropods, ticks and mites. Chemicals used for killing or preventing ticks and mites in crops or animals. Some of the early chemicals (eg [E.htm#endosulphan endosulphan]) may have also had a suggested endocrine disruptor function.
(More? Endocrine Abnormalities)

accessory pancreatic duct

(APD) This duct also called Santorini’s duct may be present as an anatomical variation due to the embryological origin of the pancreas from two pancreatic buds (dorsal and ventral). Note the main pancreatic duct (MPD) from the dorsal bud, present in the body and tail of the pancreas (also called Wirsung’s duct).
(More? Pancreas | Pancreas History)

acheiria

A limb abnormality with a missing hand or foot as described in the original classical classification of limb deficiencies.
(More? Limb Abnormalities - Classification)

achondroplasia

Musculoskeletal defect of short limb skeletal dysplasia, due to a mutation in a dominant gene encoding fibroblast growth factor receptor-3 (FGFR3). Most common limb dysplasia, with shortened long bones (mainly proximal long bones) and is difficult to prenatally diagnose. Other mutaions of this gene cause milder skeletal dysplasia (hypochondroplasia) and a lethal skeletal dysplasia (thanatophoric dysplasia).
(More? Musculoskeletal Abnormalities | OMIM Achondroplasia | FGFR3)

acrocentric

Term used to describe chrompsomes which pair with a centromere located very close to one end giving a "V" shape rather than "X" of a central centromere pair. In the human, chromosomes 13,14,15,21 and 22 are acrocentric. In bovine all chromosomes are acrocentric.
(More? Endocrine Notes)

acrolein

A reactive aldehyde (conjugated Type-2 alkenes) formed as a product of lipid peroxidation in biological systems. Recently identified as a cigarette-related lung cancer agent
(More? Abnormal Development - Smoking | PNAS Article)

Acquired Immune Deficiency Syndrome (AIDS)

A fatal disease caused by a virus (human immunodeficiency virus, HIV) that destroys the immune system's ability to fight off infection. HIV virus is capable of being transmitted from mother to fetus.
(More? Abnormal Development - Viral Infection)

acrodynia

(Greek, acrodynia = painful extremities) chronic mercury poisoning in infants and young, also called "Pink Disease" occurred throughout the world (Australia 1890's) before the recognition of mercury's toxic effects. Mercurous chloride was used in "teething powders" which were given to crying babies as a purgative agent to cleanse the system.
(More? Heavy metals | Michigan Health MercurySpillFactsheet_85689_7.pdf)

acromegaly

Abnormality in the adult, overproduction of growth hormone causes bone thickening and cartilage growth.

acroplaxome

The sperm structure which forms the acrosome plate with intermediate filament bundles of the marginal ring at the leading edge of the acrosome.
(More? Spermatogenesis | Fertilization)

acrosin

A spermatazoa acrosomal protein has a role in [F.htm#fertilization fertilization] including that of lysis of the zona pellucida (a serine protease) and in secondary zona pellucida (ZP) binding. Stored in mature spermatazoa as proacrosin.
(More? Spermatogenesis | Fertilization | OMIM Entry)

acrosome

The spermatazoa cellular structure containing a packet of enzymes located that allows it to dissolve a hole in the specialized extracellular matrix ([Z.htm#zona_pellucida zona pellucida], egg coat) surrounding the oocyte (egg). This enzymic digestion then allows the spermatazoa to penetrate and fertilize the egg. This structure is formed from the normal cellular organelle the [G.htm#golgi Golgi apparatus].
(More? Spermatogenesis | Fertilization)

acrosome reaction

The chemical change that enables release of acrosomal contents and allow a sperm to penetrate an egg.
(More? Spermatogenesis | Fertilization)

activin A

(inhibin, erythroid differentiation factor) A transforming growth factor beta (TGFbeta) superfamily member which has roles in many different tissues. Acts through binding a number of activin receptors, transmembrane ser/thr kinase receptors. This protein is involved in the process of uterine endometrium development (decidualization) of human endometrial stromal cells following blastocyst implantation.
(More? Week 2 Notes | OMIM - inhibin)

adactyly

The absence of bones metacarpal or metatarsal leading to an absence of all digits as described in the original classical classification of limb deficiencies.
(More? Limb Abnormalities - Classification | Limb Abnormalities - Hand Classification)

ADAMTS-13

A blood metalloprotease found in plasma which cleaves [V.htm#VWF von Willebrand factor (VWF)] in the A2 domain at the Tyr-1605–Met-1606 bond.

adenine

(adenine triphosphate) One of the 4 types (ATCG) of nucleotides that make up DNA. Base pairs with thymidine by 2 hydrogen bonds.

adenohypophysis

(anterior pituitary, pars distalis) The anterior part of the pituitary, which develops in the early embryo from a transient region on the roof of the pharynx called Rathke's pouch.
(More? Endocrine Development - Pituitary)

adenomatous rest

A kidney benign tumor developing from embryonic blastema cells. Blastema cells persist and under either genetic or epigenetic can change to become a neoplastic rest. These neoplastic rests can develop postnatally as a benign form (adenomatous rest) or a malignant [W.htm#Wilms_tumour Wilm's tumour] form. The rests are further characterised by the time of generation leading to different anatomical kidney locations: early intralobar nephrogenic rests (within the renal lobe) and late pelilobar nephrogenic rests (periphery of the renal lobe).
(More? [W.htm#Wilms_tumour Wilm's tumour] | [N.htm#nephrogenic_rest nephrogenic rest] | Urogenital Abnormalities | Urogenital Notes)

adenomyosis

(endometriosis interna, adenomyoma) A [U.htm#uterus uterus] disease involving infiltration (immediately adjacent to the endometrial cavity) of endometrial glands and stroma within the myometrium. Difficult to distinguish from [L.htm#leiomyoma leiomyoma].
(More? Reproductive System - Abnormalities | Medlineplus - adenomyosis)

adenovirus

A Class I virus containing a single double-stranded DNA (dsDNA), which can cause infections in the upper respiratory tract and gastrointestinal tract in many animals.
(More? Abnormal Development - Viral Infection)

adipocyte

The mature fat cell found in fat tissue and hypodermis layer of the skin.
(More? Musculoskeletal Development - Adipose | Endocrine Development - Adipose)

adipogenesis

The term used to describe the differentiation of preadipocytes into adipocytes.
(More? Musculoskeletal Development - Adipose | Endocrine Development - Adipose)

adipose

Fat, mesodermal in origin it is a type of connective tissue consisting mainly of adipocytes. The two forms of adipose are white and brown adipose tissue. Brown adipose is found in newborns (2 - 5 % of the body weight) and can be used to dissipate stored energy as heat (thermogenesis), while adults have mainly white adipose. Adipose tissue also has an endocrine function secreting the hormones leptin, adiponectin, and resistin.
(More? Musculoskeletal Development - Adipose | Endocrine Development - Adipose)

adontia

Term used to describe the total lack of tooth development.
(More? Integumentary Development - Tooth)

adnexa

(Latin, adnexae = appendages) Term used to describe any anatomical appendage (accessory structure, extension or outgrowth from the body). In reproductive anatomy used to describe appendages of the uterus "body"; ovaries, uterine tubes and uterus supporting ligaments.

adrenal gland

(suprarenal gland) The endocrine organ that anatomically sits on top of the kidneys (renal). It has two different embryonic origins, neurat crest (aderenal medulla) and mesoderm (adrenal cortex).
(More? Endocrine Notes - Adrenal Gland)

adrenal virilism

Abnormality that leads to the development of male secondary sexual characteristics in women with excessive adrenal gland activity.
(More? Endocrine Notes)

adventitia

Anatomical term describing the outermost connective tissue covering of any organ, vessel, or other structure not covered by a serosa. The covering is from the surrounding connective tissue and does not form an integral part of such organ or structure.

AFP

Acronym for Alpha-FetoProtein a protein detected in a prenatal diagnostic test.
(More? Alpha-FetoProtein)

aganglionic colon

(intestinal aganglionosis, Hirschsprung's Disease, megacolon, congenital aganglionic megacolon) see [I.htm#intestinal_aganglionosis intestinal aganglionosis]
(More? Gastrointestinal Tract Abnormalities | Neural Crest Abnormalities)

agglutination

Term used to describe clumping together, as of sperm, often due to infection, inflammation, or antibodies.

Age-specific fertility rates

A statistical value (used by Australian Bureau of Statistics) showing the number of live births (occurred or registered) during the calendar year, according to age of mother, per 1,000 of the female estimated resident population of the same age at 30 June.
(More? Australian Statistics)

Artificial Insemination

(AI) Fertility treatment, using placement of a sperm sample inside the female reproductive tract that can be carried out by a number of different techniques: intracervical insemination, intrauterine insemination, intratubal insemination.
(More? Week 1 Notes)

AIF

Acronym for Apoptosis Inducing Factor.

alar plate

Developmental term for the dorsal region of the developing neural tube (central nervous system), derived from the lateral regions of the nerual plate. In the spinal cord, this is the sensory afferent, dorsal horn region. Nomenclature may have come from the "wing-like" appearance of this region of the folding neural plate.
(More? Neural Notes | Dev Biol Development of the human spinal cord)

alopecia

Term used to describe the loss of hair.
(More? Integumentary Development - Hair)

alpha

Greek letter, (Α capital letter alpha; α lower case alpha) first letter of the Greek alphabet. The lower case form used in scientific literature to designate the first forms/variants of a similar protein, gene, energy form or substance.
(More? [greek.htm Greek Symbols])

alpha-fetoprotein

(AFP) A serum fetal glycoprotein produced by both the yolk sac and fetal liver. The presence of the protein in maternal blood is the basis of a test for genetic or developmental problems in the fetus. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly).
(More? Abnormal Development- AFP test)

alpha-fetoprotein test

(APF test) A prenatal test to measure the amount of a fetal protein in the mother's blood (or amniotic fluid). Abnormal amounts of the protein may indicate genetic or developmental problems in the fetus. Serum alpha-fetoprotein (AFP) is a fetal glycoprotein produced by the yolk sac and fetal liver. Low levels of AFP normally occur in the blood of a pregnant woman, high levels may indicate neural tube defects (spina bifida, anencephaly).
(More? Abnormal Development- AFP test)

alpha methyldopa

([M.htm#methyldopa methyldopa]) A central alpha agonist used to lower blood pressure. Used as an antihypertensive drug to lower blood pressure in pre-eclampsia, acting by either a direct or indirect central vasodilatory mechanism. A recent study suggests this drug may have a direct effect on placental and/or endothelial cell function in pre-eclampsia patients, altering angiogenic proteins. Drug commercial brandname (USA) "Aldomet", also available in combination with other drugs: methyldopa and chlorothiazide "Aldochlor", methyldopa and hydrochlorothiazide "Aldoril".
(More? Placenta Abnormalities - Pre-eclampsia | Medline Plus - Methyldopa | Effect of antihypertensive therapy with alpha methyldopa on levels of angiogenic factors in pregnancies with hypertensive disorders. Khalil A, Muttukrishna S, Harrington K, Jauniaux E. PLoS ONE. 2008 Jul 23;3(7):e2766. PMID: 18648513)

alpha smooth muscle actin

(SMA) Muscle protein, one of the 6 mammalian actin isoforms. This actin is associated with vascular smooth muscle, but SMA can also be expressed in myofibroblasts, and is involved in cell-generated mechanical tension.

alpha synuclein

A protein found in neurons. A dominantly inherited mutation in alpha-synuclein can cause Parkinson’s disease.
(More? UNSW Cell Biology)

allantois

An [E.htm#extraembryonic_membrane extraembryonic membrane], endoderm in origin extension from the early hindgut, then cloaca into the connecting stalk of placental animals, connected to the superior end of developing bladder. In reptiles and birds, acts as a reservoir for wastes and mediates gas exchange. In mammals is associated/incorporated with connecting stalk/placental cord fetal-maternal interface.
(More? Placenta | Week 2 Notes | Gastrointestinal Tract Notes)

allosteric

(Greek allos = other , stereos = solid or three-dimensional) Term used to describe proteins (receptors, enzymes, motors) that have at least 2 sites that alter the protein properties. The active site binds the principal substrate. The regulatory site(s) bind effector molecule(s) that influence the protein's biological activity.

altricial animal

Term used to describe an animal born in a helpless state, with incomplete development of sensory systems at birth. For example rats and mice are born with incomplete development of visual and auditory systems.
(More? Rat Development | Mouse Development | Other Embryos)

Alzheimer's Disease

(AD) A neurodegenerative disease associated mainly with ageing and the most common form of dementia. Involves neurons in the parts of the brain that control thought, memory and language. Histopathology is shown postmortem by extracellular beta-amyloid (Aß) fibrils plus intraneuronal tau (a microtubule associated protein) filaments. Named after Aloysius Alzheimer (1864-1915), a German psychiatrist and neuropathologist first published case of "presenile dementia".
(More? Neural Notes | Medline Plus - Alzheimer's Disease)

amelia

Term used to describe the complete absence of a limb, as described in the original classical classification of limb deficiencies.
(More? Limb Abnormalities - Classification)

amenorrhea

The absence of a menstrual period, it can be either primary (not yet had a period by age 16) or secondary (regular period that has now stopped for 3 months).
(More? Human Menstrual Cycle)

Ames test

(Salmonella test) A mutagenic and carcinogenic test of environmental compounds. Exposure of a modified bacteria to the test compound and their subsequent ability to produce reverse mutations and then resume growth.
(More? Abnormal Development)

amniocentesis

A prenatal diagnostic test involving sampling of amniotic fluid by needle aspiration for genetic analysis.
(More? Prenatal Diagnosis - Amniocentesis)

amnioinfusion

A medical procedure in which a physiologic solution (such as normal saline) is infused into the uterine cavity to replace the amniotic fluid.

amnion

An extraembryonic membrane ectoderm and extraembryonic mesoderm in origin and forms the innermost fetal membrane, produces amniotic fluid. This fluid-filled sac initially lies above the trilaminar embryonic disc and with embryoic disc folding this sac is drawn ventrally to enclose (cover) the entire embryo, then fetus. The presence of this membane led to the description of reptiles, bird, and mammals as amniotes.
(More? Placenta Notes | Week 2 Notes)

amniotic fluid

The fluid that fills amniotic cavity totally encloses and cushions the embryo. Amniotic fluid enters both the gastrointestinal and respiratory tract following rupture of the buccopharyngeal membrane. The late fetus swallows amniotic fluid.

amniotic band syndrome

(amniotic bands) A relatively rare abnormality caused by damage to the amnion, producing fiber-like bands that trap periperal structures (arms, legs, fingers, or toes) reducing local blood supply in turn leading to abnormal development of those structures or regions.
(More? Musculoskeletal - Limb Development Abnormalities)


amniotic epithelial cells

(AEC) Cells forming the epithelial layer of the amniotic membrane. These cells have also been used in recent stem cell therapeutic research.
(More? Musculoskeletal - Limb Development Abnormalities)

amniotomy

A parturition (birth) medical procedure thought to speed labor, where the amniotic sac is artificially ruptured using a tool (amniohook).
(More? Normal Development - Birth)

aminopterin

Chemical rodenticide also studied as a chemotherapy drug for treating leukemia and other cancers. Teratogenic, not used as a rodenticide in the USA because exposure to it is associated with serious birth defect.
(More? Abnormal Development)

amphimixis

(Greek, amphi = on both sides ; mixis = a mingling) Term used to describe fusion of male and female gametes, also used when referring to pronuclei fusion.
(More? Week 1 Notes)

amphiregulin

(AREG) also called schwannoma-derived growth factor (SDGF). A heparin-binding and heparin-inhibited epidermal growth factor (EGF) family member, which stimulates fibroblast and keratinocyte proliferation. In mammary glands, under induction by estrogen, it stimulates mammary epithelium proliferation during puberty.
(More? Integumentary Development - Mammary Glands | Puberty | OMIM - amphiregulin)

ampulla

Term used to describe an anatomical dilation of a tube or canal lumen. Anatomical description of the opening end of the uterine tube lying above the ovary and the enlarged initial segmeny of the semicircular canals of the inner ear vestibular system.
(More? Inner Ear | Genital System - Female Uterus)

Amyotrophic Lateral Sclerosis

(ALS, Lou Gehrig's disease) A postnatal neurological disease of the central nervous system, affecting the spinal cord motor neurons and brain. Henry Louis "Lou" Gehrig (1903-1941), was an American baseball player in the 1920s and 1930s who suffered from this disease.
(More? Neural Notes | Medline Plus - Amyotrophic Lateral Sclerosis)

anagen

The hair follicle active growth phase, hair follicle progenitors derived from the bulge interact with the mesenchymal dermal papilla cells to generate the lineages of the hair follicle (telogen phase is resting phase of hair growth cycle). (More? Integumentary Development - Hair)

anaphase

(Greek, ana = up, again) A mitotic stage, paired chromatids separate and migrate to spindle poles.
(More? Week 1 - Mitosis | Week 1 Notes)

anaphase A

The part of anaphase during which the chromosomes move.
(More? Week 1 - Mitosis | Week 1 Notes)

anaphase B

The part of anaphase during which the poles of the spindle move apart.
(More? Week 1 - Mitosis | Week 1 Notes)

anastomosis

Term used to describe the connection between two tubes. Applied to describe the connection between peripheral blood vessels without an intervening capillary bed.

anacephaly

Neral developmental abnormality, incomplete development of cerebral hemispheres and cranium. Usually related to neural tube defect at the anterior (cranial) neuropore.
(More? Neural Notes | Neural Abnormalities)

androgens

The male sex hormones, eg testosterone.
(More? Genital System - Male)

andrologist

A clinical specialist who treats male reproductive problems associated with spermatazoa.
(More? Week 1 - Spermatogenesis)

aneuploidy

Term used to describe an abnormal number of chromosomes mainly (90%) due to chromosome malsegregation mechanisms in maternal meiosis I.
(More? trisomy 21 | Meiosis)

aneurism

(Greek, aneurysma = a widening, aneurysm) A term used to describe an abnormal widening of a vessel or anatomical tubal structure.
(More? Blood Vessel)

angioblast

The embryonic precursor cell which will form the walls of both arteries and veins.
(More? Blood Vessel)

angiopoietin

(ANGPT) factors of the vascular endothelial growth factor family which are involved with blood vessel development, recognised by two tyrosine kinase receptors (Tie1 and Tie2). Angiopoietin-1 and Angiopoietin-2 appear to have opposite effects acting through the same (Tie2) receptor.
(More? Blood Vessel | OMIM - Angiopoietin 1 | OMIM - Tie2)

Animalia

The kingdom that includes animals, heterotrophic multicellular organisms that undergo embryonic development.

anlage

(German, anlage = primordium) Term used to describe a developmental structure, tissue or cells which will form a future structure.

anoikis

(Greek, anoikis = "homelessness") A form of cell death that occurs when cells loose contact with the extracellular matrix (ECM).

anosmia

Abnormality of having no sense of smell.
(More? Smell | Sensory Notes)

anovulation

The absence of ovulation, failure for an oocyte (egg) to be released from the ovary.
(More? Week 1 Notes)

anterior

Anatomical term used to describe the front or ventral surface.

anterior neuropore

(rostral, cephalic, or cranial neuropore) The initial "head end" or brain end opening of the neural tube before it closes (humans approximately 24 days postfertilization). The opening at the other "tail end" of teh neural tube is the [P.htm#posterior_neuropore posterior neuropore]. The anatomical location of the anterior neuropore in later brain development is the lamina terminalis, lying behind the pituitary gland. Failure of anterior neuropore to close leads to the neural tube defect (NTD) [#anacephaly anacephaly].
(More? Neural Abnormalities | Neural Tube Defects)

anticodon

The 3 bases on a transfer RNA (tRNA) complementary to the messenger RNA (mRNA) codon.

anticonvulsants

(antiepileptic drugs) A class of therapeutic drugs that are used to prevent and minimize seizures by acting on either ion channels, active transport, or membrane stabilization. In embryology they are teratogenic and increase the occurance of neural tube defects (NTDs). (Drug examples: Carbamazepine, Clonazepam, Ethosuximide, Phenobarbital, Phenytoin, Primidone, Valproic Acid)
(More? Neural Abnormalities | Neural Tube Defects | Drug Use)

Anti-Mullerian Hormone

(AMH, Mullerian Inhibiting Substance, MIS) A secreted factor (transforming growth factor-beta, TGF-beta superfamily) that regulates gonadal and genital tract development. Inhibits paramesonephric (Mullerian) duct development in males.
(More? Male | OMIM - AMH)

antral follicle

(secondary follicle) Term used to describe the developmental stage of ovarian follicle development following preantral (primary) in describing the sequence (primordial, preantral, antral) of follicle development within the ovary. In humans, a number of primordial follicles will begin to develop into primary follicles, some of which will then form antral follicles (secondary), with only a single antral follicle developing into the ovulating follicle (Graafian) each menstrual cycle.
(More? Week 1 - Oogenesis)

antrum

(Latin from Greek, antron = a cave, cavity; a nearly-closed cavity or bulge). Identified anatomically in many structures (ovarian follicle, bone, cardiac, gastric). In the ovary this refers to the follicular fluid-filled space within the follicle.
(More? Week 1 - Oogenesis)

apgar

Non-invasive clinical test designed by Dr Virginia Apgar (1953) carried out immediately on newborn. The name is also an acronym for: ===A===ctivity (Muscle Tone), ===P===ulse, ===G===rimace (Reflex Irritability), ===A===ppearance (Skin Color), ===R===espiration. A score is given for each sign at one minute and five minutes after the birth.
(More? APGAR | History)

aphalangia

The absence of phalanges (long bones) leading to an absent digit, finger or toe as described in the original classical classification of limb deficiencies.
(More? Limb Abnormalities - Classification | Limb Abnormalities - Hand Classification)

apnea

Respiratory term meaning the cessation of breathing.
(More? Respiratory Notes)

apoptosis

(Greek, apo = away from + ptosis = fall) Programmed cell death which occurs in the development of many systems. e.g. between digits, nervous system. Kerr JF, Wyllie AH, Currie AR. Apoptosis: a basic biological phenomenon with wide-ranging implications in tissue kinetics. Br J Cancer. 1972 Aug;26(4):239-57. Review.
(More? [N.htm#necrosis necrosis] | apoptosis )

Apoptosis Inducing Factor

(AIF) A mitochondrial protein associated apoptosis by initial chromatin condensation and high molecular weight DNA fragmentation.

appositional growth

(Latin, appositus = to put near) Term used in describing a specific form of bone growth on a pre-existing surface or growth at the periphery (appositus, past participle of appnere, to put near).

aquaeductus vestibuli

(Latin, aquaeductus vestibuli) See vestibular aqueduct, a tubular component of the inner ear.

arachnoid

(Greek, arachne = spider + -oeides = form) A meshwork (spider web-like) connective tissue covering of the central nervous system, forms part of the meningial layers. Lies between tough outer duramater and fine piamater.

Archaea

(Greek, archein = to begin), also called the Archaebacteria The kingdom (or "domain") of single-celled organisms that live under extreme environmental conditions and have distinctive biochemical features.

Archaebacteria

(Greek, archein = to begin), also called the Archaea The kingdom (or "domain") of single-celled organisms that live under extreme environmental conditions and have distinctive biochemical features.

archenteron

(Greek, arche = beginning + enteron = gut) The "primitive gut," the innermost tube of an animal embryo; lined with endoderm, it will become the digestive tract.

arginine vasopressin

(vasopressin, AVP) A hypothalamus neuropeptide hormone stored in the posterior pituitary (neurohypophysis). The hormones actions include: stimulate liver glycogenolysis, contraction of vascular smooth muscle cells and kidney mesangial cells, antidiuresis in the kidney, and aggregation of platelets. Also in mouse, this hormone has been shown to promote maternal behavior.
(More? Endocrine Development - Hypothalamus | Endocrine Development - Pituitary | OMIM arginine vasopressin)

arrhythmia

(= dysrhythmia) Term refers to cardiac abnormality of heartbeat either fast, slow, or irregular.
(More? Heart Notes)

Arnold-Chiari Malformation

A type of malformation which appears multifactorial (including inherited and acquired). Cerebellar tonsils elongate and herniate through foramen magnum into spinal canal, resulting in compression of parts of the brain and spinal cord, and disruption of cerebrospinal fluid flow. Thought to be fundamentally the same as anencephaly and spina bifida.
(More? Neural Abnormalities)

ART

acronym for Assisted Reproductive Technology. All treatments or procedures that involve the handling of human eggs and sperm for the purpose of helping a woman become pregnant. Types of ART include in vitro fertilization, gamete intrafallopian transfer, zygote intrafallopian transfer, embryo cryopreservation, egg or embryo donation, and surrogate birth.
(More? Week 1 - In Vitro Fertilization)

ART cycle

A process in which 1) an ART procedure is carried out, 2) a woman has undergone ovarian stimulation or monitoring with the intent of having an ART procedure, or 3) in the case of frozen embryos, embryos have been thawed with the intent of transferring them to a woman. A cycle begins when a woman begins taking fertility drugs or having her ovaries monitored.
(More? Week 1 Notes)

ASD

Acronym for #atrial_septal_defect atrial septal defect, a developmental defect in the formation of the dividing septum between the two atria of the heart.
(More? Heart Abnormalities)

asepsis

Term describing a sterile technique, without infection or contaminating microorganisms.

Asherman syndrome

(uterine synechiae, intrauterine adhesions) Maternal syndrome (historic name) resulting from trauma to the gravid uterine cavity, which leads to the formation of intrauterine and/or intracervical adhesions.

ASPM

Acronym for abnormal spindle-like microcephaly-associated protein.

aster

(Latin, aster = star) A star-like object visible in most dividing eukaryotic cells contains the microtubule organizing center.

astral

Having an aster and centrioles that participate in mitosis; characteristic of mitosis in animals and in nonvascular plants.

astral microtubules

Microtubules that extend from each pole of the mitotic spindle without attaching to any other visible structure.

astrocyte

A type of nervous system glial cell (non-neuronal), forms blood-brain barrier.
(More? Neural Notes)

ataxia

(Greek, a = without + taxis = order) Refers to a lack of coordination of muscule movements. Both central and peripherial neurological disorders can generate this loss of coordination.
(More? Neural Notes | Neural Abnormalities | NINDS (USA) Ataxia Telangiectasia)

ataxia telangiectasias

A neurodegenerative disease with no current cure resulting in death in teens or early 20's.
(More? NINDS (USA) Ataxia Telangiectasia | Neural Abnoormalities)

ataxia-telangiectasia mutated

(ATM) A protein kinase involved in early signaling of DNA damage (double-stranded DNA breaks) and initiates the signal transduction cascade at damage sites. ATM phosphorylates substrates involved in DNA repair and/or cell cycle control. See also Rad3-related (ATR) a broad spectrum DNA damage response signaling protein kinase.
(More? DNA Notes OMIM - ataxia-telangiectasia mutated | Entrez - ataxia-telangiectasia mutated)

ataxia-telangiectasia and Rad3-related

(ATR) (= FRAP-related protein 1) A broad spectrum DNA damage response signaling protein kinase.
(More? OMIM - ataxia-telangiectasia and Rad3-related | Entrez - ataxia-telangiectasia and Rad3-related)

atresia

(Greek, a = without + tresis = perforation) Term used for anatomical closing or absence of a cavity or opening that should exist. Used as an antomical, pathological and clinical term: esophageal atresia, biliary atresia, duodenal atresia, jejunal atresia, choanal atresia, vaginal atresia, urethral atresia, pulmonary atresia, bronchial atresia, tricuspid atresia.
(More? see [#atretic_follicle atretic follicle])

atretic follicle

An ovarian follicle that fails to mature and degenerates. Also called "atresia" referring to the process of degeneration of the ovarian follicle. At any one time the majority of follicles are destined not to complete maturation and degeneration can occur at any stage (from type 4-7).
(More? Week 1 Notes | Ovary Notes)

atrial septal defect

(ASD) Heart defect, abnormal opening or hole in the septum between right and left atria. Normally allows left to right blood shunting, though additional cardiac abnormalities causing higher right side pressure (pulmonary stenosis or tricuspid atresia) allow right to left blood shunting.
(More? Heart Abnormalities)

atrioventricular junction

(AVJ) the heart (cardiac) region lying between the two atria and the two ventricles. In the mature heart the opening is closed on the left by the mitral valve (a bicuspid valve, has two distinct leaflets) and on the right by the tricuspid valve (three distinct leaflets).
(More? Heart Notes)

atrophy

Term describing the wasting away of tissue.

auditory neurons

Neurons of the auditory ganglia (cochlear ganglia) of cranial nerve 8 (CNVIII) involved with sound detection. These neurons form as part of the anterior ventromedial otocyst epithelium and migrate into the periotic mesenchyme at the anterior part of the developing otocyst. At this location they differentiate and extend dendrites towards the developing sensory epithelia and axons to connect with central brainstem targets.

(More? Inner Ear | Hearing Notes)

auricular hillocks

External ear (auricle) embryonic origin, a series of 6 external "bumps" three on each of pharyngeal arch 1 and 2.

(More? External Ear | Hearing Notes)

Automated Auditory Brainstem Response

(AABR) The basis of a neonatal hearing test that uses a stimulus delivered through earphones and detected by scalp electrodes. Computer ananalysed electrical measurement of activity through nuclei in the hearing central neural pathway.
(More? Child Notes - Neonatal Hearing Screening)

autonomic nervous system

Involuntary nervous system; coordinates the responses of smooth muscles, cardiac muscles, and other effector organs including those of the endocrine, digestive, excretory, respiratory, and cardiovascular systems.
(More? Neural Crest Notes)

autosomal

The term decribing all the chromosomes that contribute to a cell's genetic material, except for the sex chromosomes X, Y.
(More? DNA Notes)

autosomal inheritance

Some hereditary diseases are described as autosomal which means that the disease is due to a DNA error in one of the 22 pairs that are not sex chromosomes. Both boys and girls can then inherit this error. If the error is in a sex chromosome, the inheritance is said to be sex-linked.
(More? DNA Notes)

autotroph

(Greek, autos = self + trophos = feeder) An organism that makes its own organic molecules from simple inorganic compounds (like carbon dioxide water and ammonia).

alveolar

(Latin, alveus = cavity or hollow) Term used in relation to the alveoli of the lungs. The final functional sac of the respiratory tree where gas exchange occurs between the alveolar space and the pulmonary capillaries.
(More? [respire.htm Respiratory Notes])

alveolar stage

(Latin, alveus = cavity or hollow) (aveolar phase) Term used to describe lung development, the final histological/developmental stage (Pseudoglandular, Fetal Canalicular, Terminal sac, Alveolar). This stage occurs from late fetal/neonate. The final functional sac of the respiratory tree exists, where gas exchange occurs between the alveolar space and the pulmonary capillaries.
(More? Respiratory Notes)

alveoli

(Latin, alveus = cavity or hollow) The final functional sac of the respiratory tree where gas exchange occurs between the alveolar space and the pulmonary capillaries.
(More? [respire.htm Respiratory Notes])

auditory tube

(eustacian tube, otopharyngeal tube, pharyngotympanic tube) A narrow canal connecting the middle ear space to the back of the oral cavity. The tube allows ventilation protection and clearance for the middle ear cavity. Ventilation is the pressure equalization in the middle ear. Clearance is to allow fluid drainage from the middle ear. Embryonic origin is from the first pharyngeal pouch. In development, the canal is initially both horizontal, short and very narrow leading to poor drainage and easy blockage.
(More? Middle Ear | Hearing Notes | Abnormal Hearing Notes)

axial mesoderm

Alternative name for the [N.htm#notochord notochord], an early embryonic structure lying in the midline of mesoderm within the early trilaminar embryo.
(More? [N.htm#notochord notochord] | Neural Notes | Week 3 Notes)

axial process

The precursor to the notochord. In the early embryo (week 3) epiblast structure extending from the primitive node (Hensens node) crainally, which will eventuall differentiate to for the [[N#notochord|notochord], the mesoderm structure that later replaces the axial process.
(More? notochord | Neural Notes | Week 3 Notes)

axoneme

The basic structure in cilia and eukaryotic flagella; consists of parallel microtubules in a characteristic "9 + 2 pattern".
(More? Week 1 Notes)

AZF regions

regions on the long arm of Y chromosome (AZFa, b, and c) deletions of which result in severe damage to spermatogenesis with azoospermia or severe oligozoospermia.
(More? Week 1 - Spermatogenesis | Week 1 Abnormalities)

azoospermia

Term describing the absence of spermatazoa, a male reproductive abnormality.
(More? Week 1 - Spermatogenesis | Week 1 Abnormalities)

Glossary Comments

Use this page to access brief definitions of specific embryology terms. Additional information can be accessed from links listed at the end of each definition. Glossary from the UNSW Embryology program compiled and written by Dr Mark Hill. Reference material used in preparing this glossary list includes: texts listed on page 1 "Reading" of each notes section, Department of Anatomy Publications, WWW resources from NCBI, NIH, OMIM, NHMRC (Australia), AMA (USA), Office of Rare Diseases (USA), PubMed Medline Dictionaries, MSDS, Merck Manual home edn. and WHO ART terminology (2009).

These notes are for Educational Purposes Only Please email Dr Mark Hill if you wish to make a comment about this current project.

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, April 26) Embryology A. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/A

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G
Retrieved from ‘https://embryology.med.unsw.edu.au/embryology/index.php?title=A&oldid=2996’
Powered by MediaWiki