|Embryology - 1 Dec 2023 Expand to Translate|
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- 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
- A genetics term used to describe a technique for staining chromosomes during metaphase. The resulting banding pattern is seen for centromeric or constitutive heterochromatin, the centromere appears as a stained band compared to other regions. There are several other chromosome staining techniques, including G-banding, R-banding and Q-banding.
- (More? Molecular Development - Genetics)
- Abbreviation of "caesarian section" also can be further shortened as acronym C/S (see caesarian section).
- (More? caesarean)
- (c-section, C/S) The surgical delivery of fetus through an abdominal incision, named after the roman emperor Caesar who was delivered by this method. Please note the UK/Australian "Caesarean" versus USA "Cesarean" spelling differences.
- (More? caesarean)
- (French, cafe-au-lait = coffee with milk; birthmark) describes the characteristic colour of the hyperpigmented skin patch. The common name reflects the presence at birth (congenital) or appearing in early infancy. Pigment is produced by produced by melanocytes, solitary feature is common, multiple café-au-lait macules are associated with various genetic syndromes including Neurofibromatosis type 1 and 2.
- (CB, nucleolar accessory bodies, coiled body, gems) Ramon y Cajal originally identified (1903) these small structures located in the cell nucleus. They have various suggested functions including ribonucleoprotein functions and RNA maturation. During the cell cycle they disassemble and reassemble, and are localized to the nucleolar periphery or within the nucleoli. The protein coilin is located within Cajal bodies.
- (More? Santiago Ramón y Cajal | image - CBs | image - CB electron micrograph | image - Fragile X protein and CB)
- Acronym for Congenital Anomaly of the Kidney and Urinary Tract.
- (More? renal)
calcium channel blocker
- (nifedipine) A clinical tocolytic agent used to inhibit labor (labor-inhibiting), slowing or halting uterine contractions. These drugs are used clinically to treat premature labor and permit continued fetal growth before parturition. Act on uterine smooth muscle cells to directly block the influx of calcium ions through the cell membrane, inhibit the release of sarcoplasmic reticulum (SR) intracellular calcium and increase calcium efflux from the cell.
- (More? birth)
- A histological feature seen in the developing ovarian follicle granulosa layer of some species, including human. Appears as a spherical space staining as an eosinophilic region and contains basal lamina components (type IV collagen and laminin) similar to thiose of the follicular basal lamina. Named named after Emma Louise Call (1847 - 1937) one of the first American women physician and Sigmund Exner (1846 – 1926) an Austrian physiologist. Also present in a range of human ovarian tumours.
calmodulin-dependent protein kinase II
- (CamKII, CaM kinase II) A signaling protein serine/threonine protein kinase in pathways that use calcium ions Ca(2+) as a second messenger. A recent mouse study has shown that the CamKII isoform, gamma 3 isoform is involved in signaling for oocytes arrested at meiotic metaphase II to resume meiosis (not cortical granule release) following fertilization.
- (leukocyte L1) A calcium and zinc binding protein (36 kDa) that forms about 60% of soluble cytosol protein in human neutrophil granulocytes, and is also found in monocytes, macrophages and epithelial cells. During the neonatal period, the high fecal calprotectin (f-calprotectin) values observed in preterm infants may be linked to the establishment of gut bacteria.
- (More? PLoS)
- The term used to describe the skull formed from frontal, parietal and occipital bones.
- A term describing abnormal development resulting in a permanent flexion contracture of a finger or toe.
- (More? Fetal Alcohol Syndrome)
- (fetal canalicular, canalicular phase) Term used to describe lung development, after early embryonic the second of the histological/developmental stages (pseudoglandular, fetal canalicular, terminal sac, alveolar). This stage occurs during the fetal period from week 16 to 24. During this stage there is lung bud mesenchymal angiogenesis and cellular differentiation into different stromal cell types (fibroblasts, myoblasts and chondrocytes).
- (canceled cycle) An in vitro fertilization (ART) cycle in which ovarian stimulation was carried out but which was stopped before eggs were retrieved, or in the case of frozen embryo cycles, before embryos were transferred.
- (More? Assisted Reproductive Technology)
- Acronym for Chronic Atypical Neutrophilic Dermatosis with Lipodystrophy and Elevated temperature. A very rare syndrome due to mutation in Proteasome Subunit, Beta-Type, 8 (PSMB8) gene that make up proteasomes in the cells.
- (pentalogy of Cantrell) A rare human developmental syndrome involving 5 key abnormalities: midline abdominal wall defect, lower sternum defect, anterior diaphragm defect, diaphragmatic pericardium defect and congenital heart malformation.
- (More? OMIM 313850)
- The process by which sperm become capable of fertilizing an egg, requires membrane changes, removal of surface glycoproteins and increased motility.
- The smallest blood vessels within the cardiovascular system, typically less than 10 µm in internal diameter, even smaller vessels can be found within the neural cortex (less than 5 µm). Like all blood vessels they are lined by a simple squamous epithelium formed by endothelial cells. In embryonic development they form initially from "blood islands" within both embryonic and extra-embryonic mesoderm.
- Tooth developmental stage occurring after bud and before the bell stage. Refers to the bud folding inward and acquires initially the form of an inverted cap and later the form of a bell.
- Tooth stages: lamina | placode stage | bud stage | cap stage | bell stage | all stages | Tooth Development
- (More? tooth)
- (Latin, kaput = "head"; succedaneus = "acting as substitute") Clinical term for the swelling of the scalp in a newborn often due to pressure from the uterus or vaginal wall, prior to and during birth, in the head-first (vertex) position. Appears to be a transient swelling and sometimes discolouration lasting several days and requiring no treatment.
- (CO) A colourless and odorless gas formed mainly as a by-product of incomplete combustion of hydrocarbons and can cause cytotoxicity by tissue hypoxia. Carbon monoxide enters circulation though the respiratory system, binding to haemoglobin to form carboxy-haemoglobin (COHb), with fetal haemoglobin binding with a greater affinity.
- (COOH-PLL) A cryoprotective agent that has been used to reduce damage by cryopreservation in mammalian stem cells and more recently in storing oocytes.
- (More? stem cells)
- Term used in early heart development to describe the initial gelatinous or sponge-like connective tissue separating the myocardium and the heart tube endothelium.
- The name given to the initial embryonic vessels that will form the systemic venous system. This vascular system, like most early vessels, develop initially bilaterally and symmetrical.
- (cardiomyocyte) The mature cardiac (heart) muscle cell. Cardiac muscle cells are striated, joined by specialised junctions (intercalated discs) and innervated by the autonomic nervous system.
- (CTG, cardiotocogram, electronic fetal monitor, EFM) Clinical prenatal monitoring test, usually in the third trimester, measuring both the fetal heartbeat and the maternal uterine contractions.
- (More? Heart Rate Development)
- Carnegie stages are a system of classifying embryonic development based on the external features and related internal changes that affect appearance and growth of the embryo. Note that the stages are not directly dependent on either age or size, but upon the appearance of specific embryonic features. Early human and other species embryos can be classified by these stages. The term "carnegie stages" are named after the famous USA Institute which began collecting and classifying embryos in the early 1900's.
- Clinical term describing a uterine fleshy mass containing pieces of placenta and products of conception that have not been expelled after a miscarriage or abortion.
- (More? Placenta - Abnormalities)
- (CNC) Human genetic disorder, a rare familial disease characterized by a predisposition to develop multiple endocrine tumours including Cushing's syndrome.
- The narrowing of the blood vessels in the neck, carotid arteries, that supply blood to the brain.
- The connective tissue formed from mesoderm by the process of chondrogenesis. In the embryo cartilage initially forms most of the skeleton and is later replaced by bone (ossification). In the adult, cartilage is found in many skeletal regions including the surface of bone joints.
- Clinical genetic term for the testing of genetic relatives for a mutation that has been identified in the first affected family member.
- (More? Abnormal Development - Genetic)
- (Greek, cata = down + ballein = to throw) The reactions of metabolism that break down complex molecules, such as those in food.
- The end of active growing phase of the life cycle of the hair, between growing phase (anagen) and resting stage (telogen).
- (More? hair)
- (β-Catenin) Beta-catenin is a protein that binds E-cadherin in the formation of intercellular adhesions. In development, the protein is also a key component of the Wnt signaling intracellular pathway that controls cell proliferation and differentiation.
- (Latin, cauda equina = horse's tail) The lower end, caudal, extension of the mature spinal cord. This anatomical feature develops due to the growth, in length, of the vertebral column while the spinal cord does not elongate at the same rate.
- (More? Lecture - Neural Development)
- (Latin, caudal = tail) Anatomical term referring to structures that are more towards the tail.
- (posterior neuropore, Latin, caudal = tail) The opening of the early neural tube at the spinal cord end or the tail region. Initially when the neural plate folds and fuses it leaves two openings at either end cranial and caudal that close later. In humans, the caudal neuropore closes from Carnegie stage 12 (about 26 days) over a day. Failure of caudal neuropore to close can lead to the neural tube defect (NTD) spina bifida.
- Term used to describe the process of formation of a space within an existing solid object. This process occurs developmentally in a number of different structures: in the early blastocyst forming the blastocoel, within early somites forming the somitocoel.
cavum septi pellucidi
- (CSP, cavum septum pellucidum) Part of the septohippocampal system, a brain space filled with cerebrospinal fluid (CSF) present during fetal development and lost postnatally (85% fuse by 3–6 months of age). The septum pellucidum forms the medial walls of the lateral ventricles as a thin plate of two laminae that fuse, failure to fuse forms this cavity. This space is visible in fetal ultrasound scans and is one of the landmark parameter for the measurement of Head Circumference (HC) when determining fetal age/growth.
- (More? ultrasound | Figure - Ventricular space cartoon | head | Fetal Development | birth | PMID3813041)
- Acronym for Cord Blood Units, used in defining quantities of placental cord blood collected.
- (More? Stem Cells - Cord Blood)
- Acronym for circulating cell-free fetal DNA a form of short lived fetal DNA from fetal cells circulating in the maternal blood. The basis of Non-Invasive Prenatal Testing (NIPT).
- Acronym for Connective tissue growth factor (CTGF), Cystein rich protein (Cyr61), and Nephroblastoma overexpressed gene (nov). A family of both positive and negative regulatory proteins involved in many different cellular processes (survival, cell adhesion, migration, and proliferation). Three genes involved in the Wnt1 signalling pathway (WISP-1, WISP-2, WISP-3) have been shown to be highly related to the CCN family of genes.
- (More? notochord)
- Protein of the tetraspanin family, that span the cell membrane 4 times, found on the cell surface. This protein is expressed on the oocyte surface and is required for spermatozoa fusion during fertilization.
- Acronym for Congenital Diaphragmatic Hernia, a musculoskeletal abnormality of the respiratory diaphragm. The most common form being the B#Bochdalek herniaBochdalek hernia.
- (More? Congenital Diaphragmatic Hernia)
- (caecum, Latin, caecus = "blind") Anatomical term describing within the gastrointestinal tract a pouch that connects the ileum with the ascending colon of the large intestine. This is also where the appendix is located.
- The process by which a parent cell gives rise to two daughter cells that carry the same genetic information as the parent cell. All body cells divide by the process called mitosis, except germ cells which undergo meiosis. Meiosis is a DNA reductive cell division (diploid to haploid).
- The historic theory that states: (1) All organisms are composed of one or more cells; (2) cells themselves are alive and are the basic living unit of function and organization of all organisms; (3) all cells come from other cells.
- (More? UNSW Cell Biology)
- A normal gene (proto-oncogene) which when mutated can cause unregulated cellular growth and proliferation, cancer.
- The lumen or cavity of neural tube lying within the spinal cord filled with cerebrospinal fluid and is continuous with ventricular system of the brain. In the embryo, this develops from the neural tube lumen at the level of the spinal cord.
- The theory that states "DNA specifies RNA, which specifies proteins."
central nervous system
- (CNS) The part of the nervous system made up of the brain and spinal cord. Both structures form from the neural tube which is ectoderm in origin.
centre of ossification
- (ossification centre, ossification center) The region where bone formation commences within embryonic connective tissue. In endochondral ossification, this process occurs within cartilage. In membranous ossification, this process occurs within a membrane. In addition the terms primary and secondary ossification centres refer to the timing of the bone forming process, early developmental centres are primary.
- A pair of small cylindrical structures each about 0.2 micron in diameter and 0.4 micron long, that lie at right angles to one another; present at each pole of the mitotic spindle in animal cells and in some other eukaryotes.
- (Latin, centripetal = center seeking) Term used to describe the direction of growth, movement or migration.
- The point at which the two chromatids of a single chromosome are joined.
- (More? mitosis)
- Cell structure formed from one or two centrioles and the surrounding pericentriolar material. The centrosome is the cell's main microtubule-organizing center (MTOC) and has a role in the assembly of cilia. Each dividing cell begins G1 phase with two centrioles (mother and daughter centrioles of the previous cell cycle) these then duplicate in the S phase and then segregate in M phase by association with spindle poles during mitosis.
- (More? mitosis | PMID 21576395)
- (Greek, kephale = head) Term used to relate to the head or sometimes towards the upper body.
- (More? head)
- (Greek, kephale = head) Alternate clinical (obstetric) term for vertex presentation used in birth, referring to when the fetal head is closest to the cervix, hence "presentation". The most common and safest human birth position.
- (More? birth)
- Abnormality of failure of the skull to correctly close during the antenatal period. Characterized by herniation of the meninges and may present with herniation of brain, or developmental delay. Confirmed by imaging of herniated meninges.
- (More? neural abnormalities)
- (cervical cerclage, tracheloplasty, cervical stitch) Clinical procedure for the treatment of cervical incompetence or insufficiency.
- (More? Birth - Preterm)
- (Latin, cerebellum = little brain) A central nervous system component formed from the rhombencephalon (hindbrain) region of the neural tube. The cerebellum is required for coordinated motor activities. Cells within the cerebellum are formed by the ventricular zone of the roof of the fourth ventricle and the second germinal zone (Rhombic lip).
- A narrow ventricular cavity within the mesencephalon formed from the cavity within the neural tube.
- (More? neural)
cerebral cavernous malformation
- (CCM) Vascular abnormalities of the central nervous system, mainly in the cerebellum and retina. These vascular lesions occur as densely packed vascular sinusoids lined by a thin endothelium and no intervening parenchyma. In humans, occurs as sporadic (80%) or a familial disease (20%), the latter caused by heterozygous germline mutations in any of the three so far identified CCM genes (CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10).
- Term describing genetically-based developmental abnormalities in both the central nervous system (brain, spinal cord) and renal (kidney) function. For example: X-linked oculocerebrorenal syndrome of Lowe, Joubert syndrome and Bardet-Biedl syndrome.
- (cerebral cortex, grey matter, cortex) Embryonic structure that will form the cerebral cortex of the brain. Formed in sequence from neural tube, prosencephalon (primary vesicle), telencephalon (secondary vesicle) then cerebrum or cortex.
- The ear wax which is secreted by apocrine glands in the ear canal (external auditory meatus).
- (cerclage, tracheloplasty, cervical stitch) A clinical birth procedure involving circumferential banding or suture of the cervix early (between 12 -14 weeks) or when required to prevent or treat passive dilation prior to completion of pregnancy (37 weeks), described as cervical insufficiency.
- In development of the central nervous system brain region, the most caudal early neural tube flexure (cranial flexure, pontine flexure and cervical flexure)) lying between spinal cord and rhombencephalon.
- (More? neural)
- (CI) A clinical term describing a painless and progressive dilatation and effacement of the cervix that may lead to second trimester abortions or preterm delivery. It has also been described as inability of the uterine cervix to retain a pregnancy in the absence of uterine contractions. The condition may in some instances treated clinically by cervical cerclage. The biological basis is currently undetermined with some evidence showing a genetic relationship.
- (More? Uterus Development)
- There is some data that shows the risk of spontaneous preterm labour and delivery increases in women who have a short cervix. Transvaginal ultrasound can be used to measure cervical length. Both medical therapies and treatments including cerclage have been used to prevent preterm delivery.
cervical mucus plug
- (CMP) During early pregnancy, glands located at the cervical junction between vagina and uterus secrete mucus that forms a plug or barrier between these two structures.
- (More? Birth)
- A rare type of ectopic pregnancy with implantation at the cervical canal, occurring with an incidence ranging between 1:1,000 and 1:18,000 pregnancies. Clinically, when an associated haemorrhage occurs a hysterectomy is usually performed.
- Clinical birth term describing the hormonal softening of the cervix to allow expansion in preparation for birth.
- (More? Birth)
Cervical Screening Program
- (National Cervical Screening Program) Clinical term for the detection of DNA from specific strains of human papillomavirus (HPV) from cervical samples. In Australia, this test will replace the "Pap Smear" test that identified pathological cells. Specific types of HPV infections are known precursors of cervical cancer and are also being preventively treated by the HPV vaccine.
- (More? Cervical Screening Program | human papillomavirus | National Cervical Screening Program | HPV vaccine)
- An embryonic developmental feature visible in the head region between Carnegie stage 14 to 16. It is a surface ectodermal depression associated with pharyngeal arch development at the level of the neck and marks the location where the 2nd pharyngeal arch grows over the lower 3rd and 4th arches. It is a transient surface feature lost with this overgrowth
- (Latin, cervix = neck) The female anatomical region of the uterus forming a canal that opens and connects to the vagina.
- (More? Uterus Development)
- The surgical delivery of fetus through abdominal incision. Named after the roman emperor Caesar who was delivered by this method. Please note the UK/Australian "Caesarean" versus USA "Cesarean" spelling differences.
- (More? Birth)
- Each letter sands for an associated disorder of the syndrome: Coloboma on the eye , Heart, Atresia of choanae (choanal atresia), Retardation of growth , Genital malformations, Ear malformations and/or deafness. CHARGE syndrome has an estimated birth incidence of 1 in 12,000 and is a common cause of congenital anomalies. Most affected individuals with CHARGE syndrome have mutations involving the chromodomain helicase DNA-binding protein-7.
- (Chiari I and II malformation, Arnold-Chiari malformation) Developmental abnormality with a reduced posterior fossa and herniation of the hindbrain (cerebellum, brainstem) through the foramen magnum. The two types differ in severity: Type I can be asymptomatic and Type II (Arnold-Chiari malformation) is more severe and can have other associated abnormalities, such as myelomeningocele.
- (chemotaxis, attractive guidance cue) A positive chemotaxis guidance or cue, where a substance stimulates the cell migration or growth of part of a cell towards a target. In development, this can also be combined with chemorepellent guidance, inhibiting growth or migration in a particular direction.
- (repulsive guidance cue) A negative chemotaxis guidance, where a substance inhibits the cell migration or growth of part of a cell towards a target. In neural development, a series of chemoattractive and chemorepellent cues guide axon growth during the formation of neural connections.
- (More? semaphorin 3a)
- (chemoattractive) The movement of a cell or part of a cell towards a higher (or, in some cases, a lower) concentration of a particular substance (chemical or protein) produced or located at a target region in the embryo.
- An externally worn brace commonly used for the treatment of scoliosis and thoracic hypokyphosis in some European countries, though not commonly used in either North America or the United Kingdom. The brace corrects by a system of multipoint pressure zones and expansion chambers. Dr. Chêneau fabricated the original "Chêneau Brace" in 1979.
- (More? Image - Chêneau brace | Musculoskeletal_System_-_Abnormalities#Scoliosis|Scoliosis]] | Axial Skeleton Development | Musculoskeletal System - Abnormalities)
- (Greek, chiasma = cross; plural, chiasmata) The sites of exchange of DNA between homologous chromosomes during meiosis; visible during prophase of meiosis I.
- (More? meiosis)
- (Greek, pronounced ky-MIR-uhs) A mythical monster with the head of a lion, the body of a goat, and the tail of a serpent. Today used to describe a mixing of biological molecules either: 1. animals that have been genetically engineered 2. development studies where different species cells have been mixed, example chick-quail chimera, 3. Modified proteins containing parts of 2 different proteins.
- (More? Neural Crest Development)
- (C. abortus, Chlamydia psittaci) A Chlamydiae species gram-negative bacteria associated with genital tract infections that causes abortion (chlamydiosis in pregnancy) and fetal death in mammals, including humans, and a major cause of fetal loss in sheep (ovine enzootic abortion) and cattle.
- (C. trachomatis, chlamydia) A gram-negative bacteria associated with genital tract infections. Infection has been identified as a risk factor for tubal ectopic pregnancy, associated with uterine tube damage. An infected mother can during childbirth also pass chlamydia to the neonate.
- An organic compound mainly used as a broad spectrum, non-systemic fungicide. This chemical has also been shown to inhibit mouse ovarian development through endocrine disruption.
- An abnormality of nose development where forming a congenital nasal obstruction, where there is a failure of the posterior nasal cavity (choanae) to communicate with the nasopharynx.
- Bile duct epithelial cell derived from hepatoblasts during embryonic liver development. These cells line the bile duct system and have apical cilia. Cholangiocytes function (mechano-, osmo-, and chemo-sensory) to regulate the fluidity and alkalinity of canalicular bile by reabsorptive and secretory events adjusting the final secreted bile composition. Abnormalities associated with these cells development or function are called cholangiociliopathies (polycystin-1, polycystin-2, and fibrocystin).
- (cholangiogram) A diagnostic x-ray imaging of the biliary tree to bile duct using fluorescent fluids introduced either directly into the liver (percutaneous transhepatic cholangiography) or by endoscopy (endoscopic retrograde choledochography).
- Bile Pathway: bile canaliculi → intrahepatic bile ductules (canals of Hering) → interlobular bile ducts → intrahepatic bile ducts → left and right hepatic ducts merge to form → common hepatic duct (exits liver) → joins cystic duct (from gall bladder) forming → common bile duct → joins pancreatic duct → forming hepatopancreatic ampulla (ampulla of Vater) → enters duodenum
- (More? Gastrointestinal Tract - Liver Development | Gastrointestinal Tract - Gall Bladder Development)
- Inflammation of the gall bladder generally caused by gallstones obstructing the duct from gall bladder to common bile duct and can occur in maternal gall bladder during pregnancy.
- (More? Gastrointestinal Tract Development | Medline Plus Acute cholecystitis (Gallstones) | The Merck Manual Cholecystitis)
- Term used to describe skeletal malformation due to perturbation of chondrocyte differentiation program at the growth plate.
- The process of forming cartilage, embryonically a connective tissue formed from mesoderm in the body or neural crest in the head region. In the embryo, cartilage initially forms most of the skeleton and is later replaced by bone (ossification). In the adult, cartilage is found in many skeletal regions including the surface of bone joints.
- Clinical term for placental abnormality of increased blood vessel numbers within chorionic villi. Detected by pathology counting of blood vessels in histological sections of the placenta and associated with a number of development environment (gestational diabetes, smoking, high altitude) and abnormalities (gastroschisis).
- (More? Placenta Development)
- Historical term for the notochord.
- (More? notochord)
- Within the heart ventricles, a series of tendinous chords connecting the ventricular papillary musclular walls with the atrioventricular valves (bicuspid, tricuspid). The ventricular wall attachment is through the trabeculae (trabeculae carneae).
- A patterning morphogen secreted by the dorsal Spemann organiser and localised in Brachet's cleft during frog (Xenopus) gastrulation. The protein binds to ventralizing TGF-beta, blocking its activity, and is therefore a dorsal signal.
- Clinical term for an abnormality arising from remnants of the embryonic notochord developing into a rare type of cancer. Nearly all chordomas express the T-box transcription factor brachyury.
- (CA) An intraamniotic puerperal infection described as having 3 forms: histologic, clinical (clinical chorioamnionitis, IAI), and subclinical. Intraamniotic infection is a common (2-4%) event in labor and the systemic inflammatory response can also lead to preterm birth and neonatal complications. Chronic chorioamnionitis (CCA) refers to a persistent or otherwise long-lasting infection.
(chorio-decidual space, intervillous space, maternal lacunae) Placenta development term for the series of smaller spaces (lacunae), formed by trophoblast cells, that fuse together to form the maternal blood-filled space within the placenta.
- The extraembryonic membrane generated from trophoblast and extraembryonic mesoderm that forms placenta. chorion and amnion are made by the somatopleure. The chorion becomes incorporated into placental development. The avian and reptilian chorion lies beside the egg shell and allows gas exchange.
- (More? Placenta Development)
- The fluid-filled extraembryonic coelom (cavity) formed initially from trophoblast and extraembryonic mesoderm that forms placenta. chorion and amnion are made by the somatopleure. The chorion becomes incorporated into placental development. The avian and reptilian chorion lies beside the egg shell and allows gas exchange. In humans, this cavity is lost during week 8 when the amniotic cavity expands and fuses with the chorion.
- (More? Placenta Development)
- (frondosum = leafy) The chorion found on conceptus oriented towards maternal blood supply where the majority of villi form and proliferate, will contribute the fetal component of the future placenta.
- (laeve = smooth) The smooth chorion found on conceptus away from maternal blood supply (towards uterine epithelium and cavity) with very few villi present.
- (CG, human chorionic gonadotropin, hCG) A hormone see human chorionic gonadotropin.
- (CSH, human lactogen) A hormone synthesized within the placenta by syncytiotrophoblast cells. This protein hormone (190 amino acid) has a structure is similar to pituitary growth hormone.
- (More? Placenta Development | Lecture - Placenta Development | OMIM - chorionic somatomammotropin hormone)
chronic histiocytic intervillositis
- (massive chronic intervillositis, chronic intervillositis) Rare placental abnormality and pathology defined by inflammatory placental lesions, mainly in the intervillous space (IVS), with a maternal infiltrate of mononuclear cells (monocytes, lymphocytes, histiocytes) and intervillous fibrinoid deposition.
- (massive chronic intervillositis, chronic histiocytic intervillositis) Rare placental abnormality and pathology defined by inflammatory placental lesions, mainly in the intervillous space (IVS), with a maternal infiltrate of mononuclear cells (monocytes, lymphocytes, histiocytes) and intervillous fibrinoid deposition.
chronic lung disease
- (CLD) Neonatal chronic lung disease can be caused by prolonged mechanical ventilation (MV) and oxygen-rich gas with premature infants.
chronic myelogenous leukemia
- (CML, chronic myeloid leukemia) Clinical term for a leukocyte (white blood cell) cancer associated with a genetic abnormality of a chromosomal translocation (swapping) that occurs to generate the Philadelphia chromosome. The Philadelphia chromosome t(9;22)(q34;q11) has part of chromosome 9 combined with chromosome 22 that disrupts a gene leading to a Bcr-abl fusion protein.
- (More? Philadelphia chromosome)
- (placental villi) The embryonic functional region of the placenta, singular is villus. These villi develop throughout 3 stages. Primary villi initially form from trophoblast cells (syncitiotrophoblast, cytotrophoblast) extending into the maternal decidua from the edge of the implanting conceptus. Secondary villi then form when these finger-like projections from the chorionic membrane fill with extra-embryonic mesoderm. Tertiary villi form when this core mesoderm differentiates to form blood vessels, establishing the placental circulation within the villi. Villi continue to form throughout development increasing the surface area for placental exchange. Part of this region can be removed for prenatal testing for genetic abnormalities, the technique is called chorionic villus sampling.
- Placental pathology which can occur following placental infection leading to maternal inflammation of the villous stroma, often with associated intervillositis.
chorionic villus sampling
- (CVS) The taking a biopsy of the placenta, usually at the end of the second month of pregnancy, to test the fetus for genetic abnormalities.
- A vascular complex in 3rd and 4th ventricle that differentiates to act as an endorgan synthesizing and secreting cerebrospinal fluid (CSF) into the ventricular space of the brain.
- (More? Ventricular System Development)
- The name given to adrenal medulla cells, due to their histological staining with potassium dichromate (brown).
- (Greek, chroma = color) A diffuse material within the nucleus of a non-dividing eukaryotic cell; consists of DNA and proteins.
- (More? Genetics)
- (Greek, chroma = color + soma = body, because it is stained by certain dyes) double stranded DNA coiled around histones. Condenses during mitosis and meiosis.
- (More? Genetics)
- Histological staining technique developed in the late 1960s and 1970s, that allow the differentiation of mitotic chromosomes on the basis of a unique pattern of light and dark banding.
- (More? Genetics)
- Term used to describe the growth process of intestinal tract epithelium crypts of Lieberkühn (intestinal glands) number increase during mainly postnatal intestine growth.
- (More? Intestine Development
- (cryptorchidism) A male genital abnormality where the testes remain undescended in the abdominopelvic cavity.
- (Latin, cilium = eyelid) Cellular extensions named from the hair-like appearance of a cilium; singular, cilium. In many tissues, cilia are found as epithelial cell apical surface motile specializations. In the uterine tube epithelium, after ovulation used to move the unfertilized egg, then the fertilized zygote, then blastocyst during the first week of development.
- (Latin, cilium = eyelid) An epithelium named on the basis of the cells having surface hair-like appearance of a cilium; singular, cilium. In many tissues, cilia are found as epithelial cell apical surface motile specializations. In the uterine tube epithelium, after ovulation used to move the unfertilized egg, then the fertilized zygote, then blastocyst during the first week of development.
- Genetic diseases related to the structure and function of cell surface specialization, the primary cilium, required in developmental signaling and sensory functions.
- (More? PMID 19421068 | PMID 19477114)
- (Latin, cilium = eyelid) Cellular extension named from the hair-like appearance of a cilium; plural, cilia. In many tissues, cilia are found as epithelial cell apical surface motile specializations. In the uterine tube epithelium, after ovulation used to move the unfertilized egg, then the fertilized zygote, then blastocyst during the first week of development. Two main types motile cilium and primary cilium.
- (CLZ) Drug that is a cyclic adenosine monophosphate (cAMP) modulator, acting as a phosphodiesterase inhibitor and increasing cAMP levels. Used clinically in adult conditions and diseases (muscle pain, peripheral vascular disease, heart failure), developmentally has been shown to influence the steady state of the meiotic stage, delaying meiotic resumption.
- (More? Cell Division - Meiosis)
- Central nervous system structure forming part of the fornicate gyrus along with the parahippocampal gyrus. The central nervous system has an ectoderm origin forming neural plate then neural tube.
- Genetic material structure found in prokaryotes (bacteria), and in eukaryote energy-producing organelles (mitochondria, chloroplasts). Some viruses may also have circular DNA, as either single stranded or double stranded DNA.
- Tongue surface specialisation of large size, and vary in number from eight to twelve forming an inverted letter V shape on the dorsum of the tongue immediately in front of the foramen cecum and sulcus terminals. The three types of papillae from numerous to few are: filiform, fungiform and circumvallate.
- (More? Histology HE | Histology VG | Drawing - circumvallate papillae | Tongue Development | Taste Development)
- (Latin, cis = on the same side) DNA sequences that through transcription factors or other trans-acting elements or factors, regulate the expression of genes on the same chromosome.
- (More? Molecular Development)
- Historic term describing the germinating or formative point in the yolk of an egg, particularly for birds.
- (More? Chicken Development)
- Respiratory tract epithelial cells on the luminal surface of airways. These cells have a dome shaped cytoplasmic protrusion and no cilia and their function is secretory and xenobiotic. Clara cells can act as progenitor cell in small airways replacing injured terminally differentiated epithelial cells.
- (More? Respiratory System Development)
Clara cell secretory protein
- (CCSP) A protective lung protein secreted from non-ciliated bronchiolar epithelial cells in the conducting airways of mammals. The protein increases in expression level post-natally and is thought to have antioxidant, immunomodulatory, and anticarcinogenic properties.
- A protein family which forms a component of tight junctions located between cells in the subapical region of the lateral membranes. These proteins in epithelial cells can interact with Eph/ephrin proteins during development to affect cell migration and allow cell sorting to occur.
- (cells of Claudius) Cells of the inner ear cochlea, columnar cells with microvilli overlying the basilar membrane and extend from Hensen's cells to the spiral prominence. Barrier cells that lie external to the organ of corti in endolymph.
- (Latin, clavis = key, -cula = small, "collar bone") The bone which locks shoulder to body. In mammals, the clavicle is one of the first bones to ossify by a mix of intramembranous and endochondral ossification from two centres of ossification within a single condensation. The suggested bird equilivalent, the furculae (wishbone), ossifies only by intramembranous within a single center in each condensation.
- A series of rapid cell divisions following fertilization in many early embryos; cleavage divides the embryo without increasing its mass.
- A feature of cell division forming a structure or groove in the cytoplasm during cytokinesis (division of cell cytoplasm following mitosis). The furrow forms in the cell membrane in a dividing cell as the contractile ring tightens.
- An anatomical gap or space occuring in abnormal development in or between structures. Most commonly associated with cleft lip and cleft palate. Term is also used to describe the external groove that forms between each pharyngeal arch during their formation.
- (More? Palate Development | Head Development | Lecture - Head Development | Medline Plus - Cleft Lip and Palate)
- An abnormality of face development leading to an opening in the upper lip. In the embryo, beginning in week 6 (Carnegie stage 16), there is a fusion of the maxillary processes of the first pharyngeal arch and the midline region of the frontonasal prominence. By week 7 (Carnegie stage 19) this fusion event is completed forming the upper lip, maxilla and primary palate. Clefting of the lip and or palate occurs with 300+ different abnormalities. Depending on many factors, this cleft may extend further into the oral cavity leading to a cleft palate. In most cases clefting of the lip and palate can be repaired by surgery.
- (More? Cleft Lip and Palate | Palate Development | Lecture - Head Development | Medline Plus - Cleft Lip and Palate)
- An abnormality of early fetal face development leading to an opening (cleft) in the palate either the hard, soft or both portions. Palate formation commences in the embryo with the primary palate formation in week 7 (Carnegie stage 19) and then completed in the early fetus by secondary palate formation from week 9 (fetal). Secondary palate formation is by the two palatal shelves, arising from the maxilla lateral to the tongue, elevating and fusing with each other in the midline with the nasal septum. Clefting of the palate occurs more frequently in females (57%) than in males (43%) and in most cases clefting of the lip and palate can be repaired by surgery.
- (More? Cleft Palate | Palate Movie | Palate Development | Head Development | Lecture - Head Development | Medline Plus - Cleft Lip and Palate)
- A human genetic bone disease due to a heterozygous mutation in Runx2.
- (More? Bone Development)
- (Greek, klinein = to bend, slope or incline and dactylos = digit, finger or toe) a curving of the fifth (little) finger toward the fourth (ring) finger. Can be associated with a number of genetic syndromes (Trisomy 21 (Down syndrome) and Klinefelter (XXY) syndrome), environmental abnormalities (Fetal Alcohol Syndrome) or other skeletal abnormalities.
- Clinical experimentation on patients and are designated as phase I, II, or III, based on the type of question and number of people in the study.
- Phase I clinical trials researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
- Phase II clinical trials the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
- Phase III clinical trials the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
- (text modified from NIH Clinical Trials site)
clinical pregnancy with fetal heart beat
- WHO ART terminology (2009) definition: "pregnancy diagnosed by ultrasonographic or clinical documentation of at least one fetus with heart beat. It includes ectopic pregnancy."
- A musculoskeletal abnormality of development resulting in permanent curving of the fifth finger, usually toward other fingers and can also be seen for other fingers or toes.
- (cloacal cavity) The term describing the common cavity into which the intestinal, genital, and urinary tracts open in vertebrates. Located at the caudal end of the embryo it is located on the surface by the cloacal membrane. In many species this common cavity is later divided into a ventral urogenital region (urogenital sinus) and a dorsal gastrointestinal (rectal) region.
- Forms the external lower membrane limit (caudal end) of the early gastrointestinal tract (GIT). This membrane is formed during gastrulation by ectoderm and endoderm without a middle (intervening) layer of mesoderm. The membrane breaks down to form the initial "anal opening" of the gastrointestinal tract. The upper end of the gastrointestinal tract has a similar embryonic membrane, the buccopharyngeal membrane.
- A term used to describe the appearance of plasma cell nuclei due to the clumping of the chromatin at the nucleus periphery. More clearly seen in tissue plasma cells that the bone marrow smear, where they are sometimes confused with the basophilic erythroblasts.
- (CC) A fertility drug taken orally to promote the process of follicle/egg maturation in superovulation therapy. The drug stimulates the hypothalamus to release GnRH, activating the HPG axis to induce ovulation. (CC) an anti-estrogen (MRL-41) therapy for WHO group II (eu-oestrogenic) infertility associated with polycystic ovary syndrome. Used for more than 40 years it is a simple, cheap treatment, with low side effects and yields a 25% live birth rate. Alternative therapeutics being considered are metformin, aromatase inhibitors and low-dose FSH.
- (Greek, klon = twig) A population of genetically identical individuals or cells descended from a single ancestor.
- (More? Dolly the Sheep)
- The historic common (slang) term for talipes equinovarus a congenital deformity of the foot (occurs approximately 1 in 1,000 births).
- (More? talipes equinovarus)
- Historic clinical term for a symmetrical joint swelling occurring in patients of both sexes between 5 to 20 years of age with congenital syphilis. Joint swelling is usually in the knees, but can also affect the ankles, elbows, wrists and fingers. Named after Henry Hugh Clutton who first described the condition in 1886.
- Acronym for Central Nervous System. The structures formed from the neural tube, the brain and spinal cord.
- ectoderm - neural plate - neural tube - central nervous system
- (More? neural)
- (Latin, coacervatus = heaped up) Discrete tiny droplet into which proteins and polysaccharides can spontaneously concentrate.
- The uterine epithelium feature located where the blastocyst had entered the uterine wall. In humans, seen approximately day 12 following fertilization.
- (More? Week 2)
- (Latin coartare = to press together) Term used to describe a narrowing (stricture, constriction) associated with aortic arch developmental abnormality.
- (More? cardiovascular abnormalities)
coarctation of the aorta
- (Latin coartare = to press together) Term used to describe a developmental abnormality of narrowing (stricture, constriction) of the aortic arch.
- (More? cardiovascular abnormalities)
- A depression in the plasma membrane, lined with clathrin molecules; an intermediate structure in receptor-mediated endocytosis.
- (cumulus-oocyte complex) Acronym for Cumulus-Oocyte Complex.
- The paired inner ear hearing structure that converts mechanical vibrations into an electrical neural signal to be eventually passed to the auditory cortex, how we "hear". The cochlea has many internal structures that embryonically form from the simple epithelium of the otocyst (otic vesicle), which itself formed in early embryonic development from the otic placode. Note there is no "r" on the end of the word.
- (bionic ear) A generic term term for the medical device that is implanted into the head to aid hearing in a deaf person. First developed in and successfully used 1978 by Graeme Clark, there are now a variety of different implant devices. By the year 2000 more than 13,000 children worldwide have received these implants.
- Embryonic hearing structure, which will form the coiled cochlear duct and contribute to the saccule.
- A bony channel containing the fibrous periotic duct. It connects the basal turn of the cochlea perilymphatic space with the subarachnoid space of the posterior cranial cavity.
- (CNVIII, vestibulocochlear ganglia) The auditory component of the vestibulocochlear ganglia containing the neural cell bodies of the cochlear nerve.
- A protein forming the major constituent of the inner ear extracellular matrix.
- (Cochrane Database) An international organisation in which people find, appraise and review specific types of studies called randomised controlled trials. The Cochrane Database of Systematic Reviews contains regularly updated reviews on a variety of health issues and is available electronically as part of the Cochrane Library. There is a Video explaining the Cochrane Review process.
- (More? Statistics | Cochrane Collaboration | Cochrane Australia | Cochrane evidence | cochrane library | Video - Cochrane Review process)
- Refers to two alleles that each contribute to the phenotype of a heterozygote.
- A group of three nucleotides that specifies a single amino acid residue.
- Greek, koilma = cavity) Term used to describe a fluid-filled cavity or space. Placental vertebrate development have both extraembryonic (outside the embryo) and intraembryonic (inside the embryo) coeloms. The extraembryonic coeloms include the yolk sac, amniotic cavity and the chorionic cavity. The initial single intraembryonic coelom located in the lateral plate mesoderm will form the 3 major body cavities: pleural, pericardial and peritoneal.
- (More? Coelomic Cavity Development)
- A sampling of extracoelomic fluid usually for an early prenatal diagnostic technique.
- An organic molecule (but not a protein) that is a necessary participant in an enzyme reaction.
- A genetic term for a multi-protein subunit complex required to keep the sister chromatids together until their separation at anaphase (both in mitosis and meiosis). Cohesin also with a transcriptional coactivator (mediator) form rings that connect two DNA segments. In embryonic stem cells, this physically and functionally connects the enhancers and core promoters of active genes.
- A helical fibrous abundant protein of the extracellular matrix. The regular structure found principally in the structural protein collagen; the collagen helix consists of three polypeptide chains.
- The chicken middle ear ossicle (bone) forms from the proximal ectomesenchyme of the second pharyngeal arch. The footplate of the bone inserts into the inner ear oval window and the shaft then spans the middle ear cavity and the artilaginous extracolumella inserts into the tympanic membrane.
- The maternal mammary gland secretion that occurs at birth which precedes the secretion of milk.
- (More? Mammary Glands)
- A neural developmental abnormality occurring as an enlargement of the brain occipital horns resulting from white matter in the posterior cerebrum failure to develop. The brain occipital horns refer to the posterior or rear portion of the lateral ventricles (cavities) of the brain.
- A type of chromatography in which the stationary phase is an insoluble material packed into a glass or metal column.
- An association between individuals of two species in which one organism benefits without harming the other one, as in commisural bacteria in the gastrointestinal tract.
- Neural term for the axon connections formed between the bilaterally symmetrical central nervous system that allow communication between the two halves.
- Bacteria that postnatally populate the gastrointestinal tract and assist in processing waste products of digestion.
common cardinal vein
- (duct of Cuvier) Early vein that occurs as a pair of transverse vessels that drain the anterior and posterior cardinal veins into the sinus venosus.
- Membrane-associated structures that allow small molecules to pass freely between two adjacent cells.
comparative genomic hybridization
- (CGH, comparative genomic hybridisation, chromosomal microarray analysis) A prenatal screening technique that allows detection of chromosomal abnormalities. This new technique is currently also being developed and tested for in vitro fertilization screening.
- A molecule whose inhibitory effects on an enzyme can be overcome by increased substrate concentration.
- A set of blood proteins that attack microbial invaders.
complementarity determining region
- (CDR) The segment of an immunoglobulin molecule most involved in binding antigen; so called because its shape is complementary to that of the antigen.
- Types of diseases which aggregate in families but do not segregate in a Mendelian fashion.
- (CT, CT scan, CAT) A new imaging technique begun in 1970's using x-ray and a computer to produce images either as individual slices or reconstructed to give three dimensional (3D) views of specific anatomical regions or structures. See also multidetector computed tomography (MDCT) that uses several detectors.
- The entire product of conception, that is all the structures derived from the original zygote. This includes not only the embryo, then fetus, but also the placenta and membrane components formed from this original cell. All the conceptus components therefore also share the same genetic content formed by fertilization.
- (More? Week 1)
- Acronym for Coronary Heart Disease.
- (More? Cardiovascular Abnormalities)
- (chondroitin sulfate) An extracellular matrix glycosaminoglycan of alternating sugars (N-acetylgalactosamine and glucuronic acid). A proteoglycan is formed when it is attached to a protein. In zebrafish, expression is required for normal cardiac atrioventricular canal formation.
- (More? Lecture - Extracellular Matrix | PMID 19890913)
- The term used to describe one of the two major classes of hearing loss involving external and middle ear abnormalities (other form is sensorineural loss).
- Already present at birth, often used to describe defects present at birth, congenital anomalies or congenital defects. The euphemism or informal term "birth defects" is not an appropriate description to be used.
- (More? Human Abnormal Development)
congenital adrenal hyperplasia
- (CAH, adrenal virilism) Abnormality of the fetal adrenal cortex, alters cortisol and androgens with different effects dependent upon sex: in females masculization of the external genitalia; in males, disorder often unnoticed until postnatally. In both sexes, accelerated skeletal growth and sexual maturation is seen in late childhood. Caused by a deficiency or absence of the enzyme 21-hydroxylase in the adrenal cortex. Grouped with the Disorders of Sex Development (DSD).
- Developmental abnormalities detected before or present at birth. There are no internationally agreed definitions for congenital anomalies and there are a range of classifications including the International Classification of Diseases (ICD), developed by the World Health Organization (WHO) to enable comparability for mortality statistics.
- (More? Human Abnormal Development)
congenital dislocated hip
- (congenital hip dislocation, congenital hip dysplasia, developmental dysplasia of the hip, DHH) See the preferred term developmental dysplasia of the hip (DHH), which includes presentation following a normal examination of the hips in the newborn period. Term refers to a spectrum of musculoskeletal disorders of hip instability due either to the femoral head being able to move outside the acetabulum (luxation or dislocation), or abnormally within the acetabulum (subluxation or partial dislocation).
congenital rubella syndrome
- (CRS) Term describing the fetal developmental effects of a maternal rubella virus infection during pregnancy, especially during the first trimester, causing a constellation of congenital malformations. CRS can also cause miscarriage, fetal death, or stillbirth. ICD-11 KA72.8 Congenital rubella syndrome.
- Term describing the linking (connecting) region of the embryonic disc to the chorionic membrane wall by a short region (stalk) of extraembryonic mesoderm. The connecting stalk relative to the embryonic disc lies lies at the caudal end below both the primitive streak and the cloacal membrane. This extraembryonic mesoderm will later develop blood vessels and contribute to the placental cord (umbilical cord) structure. In humans, this early structure forms during week 3 of development.
- (gap junction protein) Family of transmembrane proteins that assemble to form channels between two adjacent cells for rapid cell communication (signaling). A gap junction is formed from six connexin molecules on one cell forming a hemi-channel (connexon) which attaches to the same structure on an adjacent cell. (Cx26, Cx31, Cx43, Cx40)
- (More? - Cell Junctions)
- (Cx43) A gap junction protein expressed in the human placenta required for the fusion of cytotrophoblast cells to form a syncytiotrophoblast cell.
- (More? - Cell Junctions | PMID 18783825)
- A developmental form of cell to cell signaling that arrests cell division in a population of cells when they reach a high or specific density and contact each other. It is seen in epithelial and mesenchymal development and is also a key anticancer mechanism, limiting the proliferative activity of cells. Cancer cells grown in vitro do not respond to contact inhibition.
- Clinical term for a reason why a drug or vaccine must not be given to a patient.
- A diagnostic test named after Robin Coombs (1921-), a British immunologist who developed a technique of using antibodies that are targeted against other antibodies used in the test for erythroblastosis fetalis (Haemolytic disease of the newborn).
- (More? Placenta Development- Abnormalities | Blood Groups and Red Cell Antigens Hemolytic disease of the newborn)
copy number variation
- (CNV) Genetics term referring to a variability in genome DNA when comparing differences of two or more genomes. The size difference ranges from one kilobase to several megabases in size and occupy about 5–12% of the human genome.
- (human umbilical cord blood, HUCB) A term used to describe blood collected from the placenta usually after birth. Has been identified as a source of stem cells with potential therapeutic uses and is stored in Cord Blood Banks throughout the world.
- (More? Placenta Development | [[Stem Cells - Placental Cord Blood])
- (umbilical cord knot) Term describing umbilical or placental cord knotting. A knot is a general term describing a compact intersection of interlaced material, such as cord, ribbon, or rope. This occurs in about 1% prevents the passage of placental blood, pseudoknots also occur usually with no effect.
- A term used to describe at birth the presence of the umbilical cord between the fetal presenting part and the cervix, with or without membrane rupture.
- A term used to describe at birth the descent of the umbilical cord through the cervix alongside (occult) or past (overt) the presenting part in the presence of ruptured membranes (incidence of 0.1% to 0.6%).
- (atrial natriuretic peptide-converting enzyme) A cardiac enzyme (protease) also found in the pregnant uterus that activates atrial natriuretic peptide (ANP). ANP is a cardiac hormone that regulates blood pressure. A recent study (PMID 22437503) suggests that corin and ANP together have a role in placentation, by promoting trophoblast invasion and spiral artery remodelling.
- An eye structural component of the cornea. In chicken, formed by a two-stage process of collagen fibril deposition, a primary stroma secreted by epithelial cells and a secondary stroma by the invading neural crest cells (corneal keratocytes).
- (More? Sensory - Vision Development)
Cornelia de Lange Syndrome
- (CdLS) genetic abnormality due to partial deficiency for NIPBL, which encodes a cohesin regulator, is associated with small changes in the expression of many genes. Resulting in a class of multi-organ system birth defect syndromes termed cohesinopathies, named for the chromatin-associated protein complex cohesin, which mediates sister chromatid cohesion. Both a mouse (PMID 19763162) and zebrafish (PMID 22039349) model has recently been described for this disorder.
- (More? PMID 19763162 PMID 22039349 PMID 15146185)
- (interstitial pregnancy) Actually means a pregnancy in the rudimentary horn of a bicornuate uterus, the term is used to describe an interstitial pregnancy.
- (More? Ectopic Implantation)
- The granulosa cells that directly surround the oocyte, within the antral follicle of the ovary. These cells are released along with the oocyte at ovulation and provide physical protection and the initial structural barrier that spermatazoa must penetrate during fertilization. Other granulosa cells within the follicle include: membrana granulosa and cumulus oophorus.
- Embryonic origin (mouse) for all coronary vessels is from angiogenic sprouts of venous endothelial cells from the sinus venosus.
- (More? Coronary Circulation Development)
- (Latin, corpus = body) Histology term for a characteristic feature of the prostate of rounded eosinophilic bodies located in the secretory alveoli. The average diameter is about 0.25 mm (up to 2 mm) and appear from the seventh month of fetal development. Their number increases with age (in particular past 50) and may undergo calcification and may also appear in semen.
- (Latin, corpus = body, albicans = whitish) The histological structure formed by luteolysis of the corpus luteum in the ovary. If implantation does not occur and the hormone hCG is not released the corpus luteum degenerates and the structure is white, not yellow, because of the absence of steroid hormone synthesis/accumulation.
- (Latin, corpus = body, luteum = yellow) The remains of ovarian follicle formed after ovulation that acts as an endocrine organ (produce progesterone and oestrogens) supporting pregnancy and preventing menstruation (loss of the endometrial lining). Formed during the luteal phase (secretory phase) of the menstrual cycle by proliferation of both follicular granulosa cells (granulosa lutein cells) and thecal cells (theca lutein cells), which produce progesterone and oestrogens. If fertilization and pregnancy does not occur, the corpus luteum degenerates to form the corpus albicans. Regnier de Graaf (1641 – 1673) first observed it in the ovary of a cow as a yellow structure, the yellow colour is caused by accumulation of steroidal hormones.
- (Latin, corticalis = at the outside) outer layer, used in association with medulla (innner layer or core) a general anatomical description that can be applied to describing an organ with a layered structure. Term is also used to describe the outer cellular (grey matter, cerebral cortex) layer of the central nervous system.
- (Latin, corticalis = at the outside) like the bark of a tree, usually combined with medulla meaning the core. Also used to describe the outer cellular layer of the central nervous system.
- The oocyte cytoplasm prior to fertilization contains just beneath the plasma membrane (cortical) many specialized secretory vesicles (granules). After fertilization, these vesicles fuse with the plasma membrane, releasing their contents, which block polyspermy.
- (More? Fertilization)
- The outer neural tube region where post-mitotic neuroblasts migrate too along radial glia to eventually form the adult cortical layers.
- (More? Neural System Development)
- (pyramidal tract) Neural term describing the central nervous system connection between the cortex (sensorimotor areas) and the spinal cord involved with mainly the motor (skeletal muscle) control. Within the brainstem about 80% of the fibres crossover to opposite sides (pyramidal decussation) and continue to descend in the spinal cord lateral white column of the opposite side. The remaining 20% of the fibres do not cross (ipsilateral) in the ventro-medial white column, to innervate bilaterally the more medially located motor neurons of the axial and proximal muscles. At birth this pathway has not completed myelination, which continues postnatally, and leads to the presence of the primitive reflex called the Babinski reflex.
- (More? Neural System Development | Neural Exam - Newborn reflexes - plantar reflex | Neonatal Development | Medline Plus - Babinski's reflex)
- An endocrine steroidal hormone produced by the adrenal cortex. Clinically, corticosteroids are also used for lung maturation of the premature neonate.
- (More? Endocrine - Adrenal Development | Endocrine System Development | Respiratory System Development)
- (CRH) A hypothalamic neuropeptide hormone, which is also produced by embryonic trophoblast and maternal decidua cells, with receptors in several reproductive organs. Thought to have a role in endometrial decidualization, blastocyst implantation and early maternal tolerance.
- ("sharing the same blood") Genetic term refers to the property of being from the same kinship as another person and therefore sharing genetic material. The percentage of consanguinity between any two individuals decreases fourfold as the most recent common ancestor recedes one generation.
- (More? Abnormal Development - Genetic)
- (Greek, kotyle = a deep cup) In the embryos of seed plants, the "seed leaves," in which nutrients are stored for use after germination. In placental animals, the term is also to describe the leaf-like structure of the placenta surface as placental septa grow into the intervillous space. These villi clusters (15 -30) are the cotyledons and appear in humans during the second trimester (fourth and fifth months) of development.
- (More? Placenta Development)
- (Bulbourethral 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.
- (More? Genital - Male Development)
- (midbrain or cephalic flexure) In development of the central nervous system brain region, the most cranial early neural tube flexure (cranial flexure, pontine flexure and cervical flexure)), lying between the mesencephalon and prosencephalon, of the three flexures (bends) that initially form as the nueral tube grows and elongates.
- (More? Neural System Development)
- (rostral, cephalic or anterior) The opening of the early neural tube in the head region. Initially when the neural plate folds and fuses it leaves two openings at either end cranial and caudal that close later. In humans, the cranial neuropore closes at Carnegie stage 11 (about 24 days) within a few hours; closure is bidirectional, it takes place from the dorsal and terminal lips and may occur in several areas simultaneously.
- (More? Neural System Development)
- (CFNS) A human X-linked developmental disorder caused by a mutation in ephrin-B1 affecting mainly females. Characterised by abnormal development of cranial and nasal bones, craniosynostosis (premature coronal suture fusion), and other extracranial anomalies (limb polydactyly and syndactyly).
- (More? Skull Development)
- A common destructive tumorogenic lesions of the hypothalamus and pituitary gland that can occur when remnant cells from Rathke's pouch remain forming a tumour.
- Abnormal development of the neural tube defect class with an abnormal opening of the skull and vertebral column.
- Abnormal development of the neural tube defect class, with failure of fusion of the entire neural tube.
- The term describing the premature closure of the skull sutures, or fusion of skull bones, that may cause skull and brain abnormalities. There are at least 8 different disorders with six related to the fibroblast growth factor receptor (FGFR); Pfeiffer syndrome, Apert syndrome, Crouzon syndrome, Beare-Stevenson syndrome, FGFR2-related isolated coronal synostosis, Jackson-Weiss syndrome, Crouzon syndrome with acanthosis nigricans (AN), and Muenke syndrome.
- Acronym for Cyclic-AMP response element binding protein. CREB is a member of the basic region leucine zipper (bZIP) family of transcription factors and requires phosphorylation to become a biologically active transcriptional activator. CREB binds to CRE (Cyclic-AMP response element) which is the final target of many extracellular and intracellular signals (e.g. cAMP, calcium, neurotrophins).
- (More? Molecular Development)
- Acronym for Cyclic-AMP response element binding protein A involved in gene activation. Drosophila have two genes (A and B-17A) encoding the cAMP response element binding (CREB) protein family members. These proteins have mammalian equilivants with RNA polymerase II transcription factor activity, DNA binding, transcription factor activity, protein homodimerization activity.
- (More? Molecular Development)
- The term describing a neurological abnormality due to insufficient thyroid hormone during neural development. The main cause of this disorder is an insufficiency or lack of iodine in the diet.
Cri du Chat syndrome
- (CdCS) Describes a genetic disorder from a deletion of variable size on the short arm of chromosome 5 (5p-). The incidence ranges from 1:15,000 to 1:50,000 live-born infants. The main clinical features are a high-pitched monochromatic cry, microcephaly, broad nasal bridge, epicanthal folds, micrognathia, abnormal dermatoglyphics, and severe psychomotor and mental retardation. Other malformations may occur in cardiac, neurological and renal abnormalities, preauricular tags, syndactyly, hypospadias, and cryptorchidism.
- Anatomical structure of the head, describing the skull perforated portion of ethmoid bone that allows passage of olfactory axons from nasal epithelium to olfactory bulb.
- (cysteine-rich secretory protein) A a group of proteins (CRISP1, CRISP2) recently suggested to have a role in spermatozoa-oocyte (sperm-egg) fusion through binding to egg-complementary sites.
- (More? Fertilization)
- (CRISPR-Cas9) Acronym for Clustered Regularly Interspaced Short Palindromic Repeats, a research molecular biology technology used for genome engineering. Also called CRISPR/Cas9 (CRISPR-associated nuclease 9) technique that can be used to specifically knock out a gene of interest. While a powerful research technique there are concerns about its possible application to human embryos. Nature News 12 March 2015
- Inner ear structure associated with equilibrium located in the ampulla of the membranous semicircular canals a region with both supporting and hair cells. The hair cell cilia are embedded in the gelatinous cupula.
- (critical period of development) The term used to describe a developmental time when exposure to a teratogen can lead to a developmental abnormality, which can be further divided into an early major and later minor developmental abnormality. The defined critical period will differ in timing and length for different systems.
- Acronym for Crown-Rump Length also historically called the "greatest length" (GL). Used in embryology to accurately stage the early embryo. Used in clinical ultrasound as a measurement between the periods of 7 to 13 weeks as an accurate estimation of the gestational age.
- (CRL, greatest length, GL) A measurement used in embryology to more accurately stage the early embryo. Measured from the curvature at the top (crown) to the curvature at the bottom (rump) of the "C-shaped" early embryo. Used in clinical ultrasound as a measurement between the periods of 7 to 13 weeks as an accurate estimation of the gestational age.
- (CPs) A gastrointestinal tract immune system structure formed by small clusters of lymphoid cells with an immature lymphocyte phenotype and dendritic cells located in the in the basal lamina propria. Part of the gut-associated lymphoid tissue (GALT) and hypothesized as a possible site of extrathymic T cell development.
- A technique for freezing tissue or cells to preserve for use at a later date. In this report, cryopreserved embryos are referred to as frozen embryos.
- The term describing an anomaly of eye development, with a continuity of the skin from the forehead to the cheek over a malformed eye. Classified into three types: complete, incomplete and abortive.
- (More? Sensory - Vision Abnormalities)
- An abnormality of either unilateral or bilateral testicular descent, occurring in < 30% premature and 3-4% term males. Descent may complete postnatally in the first year, failure to descend can result in sterility.
- Acronym for chorionic somatomammotropin hormone, a placental hormone.
- An epithelial layer formed by cells with a cuboidal shape (morphology), compared to the other two main hsitological cell shapes (squamous, columnar). Cuboidal, equal height and width, for example, endodermal or peripheral ectodermal layers of the trilaminar embryo.
- (COC) Describes the complex of cells released at ovulation, consisting of the oocyte and the surrounding granulosa cells (cumulus cells).
- (Latin cumulus = a little mound Greek, oon = egg + phorus = bearing) The granulosa cells that form a column of cells that attaches the oocyte to the antral follicle wall within follicles of the ovary. This column of cells is broken or separates during ovulation to release the oocyte from its follicle attachment. Other granulosa cells within the follicle include: membrana granulosa and corona radiata.
- Term used to describe a molecular heterodimer formed by combination of two growth factors; growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15). Cumulin acts on oocyte associated granulosa cells activating TGF-beta signaling pathways (both SMAD2/3 and SMAD1/5/8), promoting proliferation, and expression of genes associated with oocyte-regulated granulosa cell differentiation.
- In the vestibular system, the basophilic material on the cupulae of the semicircular ducts, an postnatal ageing phenomenon seen in some vestibular labyrinth.
- (hypercortisolism) A relatively rare metabolic hormonal disorder caused by prolonged exposure of the body’s tissues to high levels of the adrenal hormone cortisol, most commonly affects adults aged between 20 to 50 and also the obese with type 2 diabetes.
- (More? Endocrine - Adrenal Development | NIH - NIDDK)
- (Chemokine, Cx3C motif, Ligand 1; fractalkine, neurotactin) A chemokine identified in both membrane-bound and soluble isoforms. May be involved in implantation, as expressed on uterine glandular epithelial cells during the mid-secretory phase of the menstrual cycle. After implantation expressed by syncytiotrophoblasts (apical microvillous plasma membrane).
- Clinical term referring to a blue coloration of the skin and mucous membranes due to the presence of deoxygenated haemoglobin. Can be due to several different causes including cyanotic heart disease.
cyanotic heart disease
- Clinical term referring to a congenital heart abnormality (defect) resulting in lack of oxygen that causes cyanosis, a blue coloration of the skin and mucous membranes due to the presence of deoxygenated hemoglobin.
- Drug used in the treatment of various cancers and some autoimmune disorders. It is converted in the liver, by oxidase enzymes, to its active forms and has identified developmental teratogenic activity.
- (cyemic, cyemata) Historic term referring to the embryonic cells of the conceptus.
- The pathological term describing a fibrous capsule containing fluid.
- (Greek, kytos = hollow vessel or container) Prefix referring to a "cell" or "cellular", as is the the suffix "-cyte".
- (Greek, kytos = hollow vessel + chroma = color) One of a set of heme-containing electron carrier proteins in mitochondria that change color as they accept or donate electrons.
- (Greek, kytos = hollow vessel + kinesis = movement) The division of the cell cytoplasm and its contents that occurs following mitosis in cell division leading to two separate daughter cells. This process overlaps mitosis telophase and generates two separate plasma membranes.
- A virus that for infection of early embryos is fatal, infection of later fetuses can lead to blindness, deafness, cerebral palsy, and mental retardation.
- (protoplasm) Cell biology term for the the cell compartment lying inside the plasma membrane and outside the nucleus.
- (CPLs, oocyte cytoplasmic lattices) Intracellular structures found in mammalian oocytes and preimplantation embryos. Their suggested role is to restrict the localization of maternal effect genes. In mice 2 such genes, Padl6 and Mater, are required for development beyond the two-cell stage.
- The "cellular" trophoblast layer surrounding (forming a "shell") the early implanting conceptus. Beginning at uterine adplantation, proliferation and fusion of these cells is thought to form a second outer trophoblast layer, the syncytiotrophoblast. The cytotrophoblast layer contributes to formation of the placental villi, the functional component of the fetal placenta.
- (cytosine triphosphate) One of the four types of nucleotides (ATCG) that make up DNA. This nucleotide base pairs with guanine by 3 hydrogen bonds. This nucleotide is also associated with the epigenetic process of methylation, forming 5-methylcytosine, that leads to transcriptional gene silencing in vertebrates.
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.
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Cite this page: Hill, M.A. (2023, December 1) Embryology C. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/C
- © Dr Mark Hill 2023, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G