|Embryology - 26 Feb 2017 Expand to Translate|
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- 1 Glossary Links
- 2 I
- 2.1 ICD
- 2.2 ICMART
- 2.3 ICSH
- 2.4 idiogram
- 2.5 idiopathic
- 2.6 ICSI
- 2.7 IHBD
- 2.8 ileocecal valve
- 2.9 ileum
- 2.10 immunisation
- 2.11 implantation
- 2.12 incidence rate
- 2.13 incomplete abortion
- 2.14 incus
- 2.15 induced abortion
- 2.16 induced pluripotent stem cell
- 2.17 induction
- 2.18 infantile hemangioma
- 2.19 infectious disease
- 2.20 infective dose
- 2.21 infective endocarditis
- 2.22 inferior
- 2.23 infertility
- 2.24 infranasal depression
- 2.25 infundibulum
- 2.26 inguinal canal
- 2.27 Inhibin A
- 2.28 Inhibin B
- 2.29 iniencephaly
- 2.30 initial segment
- 2.31 inner cell mass
- 2.32 inner phalangeal cells
- 2.33 inner pillar cells
- 2.34 isthmus
- 2.35 insular cortex
- 2.36 insulin
- 2.37 integument
- 2.38 interatrial septum
- 2.39 interferons
- 2.40 interferon-alpha
- 2.41 interfollicular epidermis
- 2.42 interleukins
- 2.43 internal auditory meatus
- 2.44 International Classification of Diseases
- 2.45 interphase
- 2.46 interstitial cell
- 2.47 interstitial cells of Cajal
- 2.48 interstitial cell stimulating hormone
- 2.49 interstitial growth
- 2.50 interstitial pregnancy
- 2.51 intrahepatic bile duct
- 2.52 interventricular septum
- 2.53 interzone
- 2.54 intestine
- 2.55 intestinal aganglionosis
- 2.56 intestinal immune system
- 2.57 intra-amniotic infection
- 2.58 intra-amniotic inflammation
- 2.59 intracytoplasmic sperm injection
- 2.60 intra-embryonic coelom
- 2.61 intraflagellar transport
- 2.62 intrahepatic bile ductule
- 2.63 intramembranous ossification
- 2.64 intrapartum
- 2.65 intrauterine
- 2.66 intrauterine device
- 2.67 intrauterine growth restriction
- 2.68 inversion mode
- 2.69 in vitro
- 2.70 in vitro fertilization
- 2.71 in vitro maturation
- 2.72 in vivo
- 2.73 in vivo fertilization
- 2.74 inotropes
- 2.75 involution
- 2.76 Iodine
- 2.77 ischemia
- 2.78 islets of Langerhans
- 2.79 isoflavone
- 2.80 isolated levocardia
- 2.81 isotropic
- 2.82 isotropic band
- 2.83 isotropic resolution
- 2.84 isthmus
- 2.85 IUD
- 2.86 IUGR
- 2.87 IUI-donor
- 2.88 IVF
- 2.89 Izumo sperm-egg fusion protein 1
- 3 Glossary Comments
- 4 Glossary Links
- 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
- Acronym for International Classification of Diseases the World Health Organization's classification used worldwide as the standard diagnostic tool for epidemiology, health management and clinical purposes. This includes the analysis of the general health situation of population groups. It is used to monitor the incidence and prevalence of diseases and other health problems.
- Acronym for the International Committee for Monitoring Assisted Reproductive Technology.
- "ICMART is an independent, international non-profit organization that has taken a leading role in the development, collection and dissemination of worldwide data on assisted reproductive technology (ART). We provide information on availability, effectiveness and safety to health professionals, health authorities and to the public."
- Acronym for Cell Stimulating Hormone an anterior pituitary hormone.
- (karyogram, chromosome map) Term describing a drawing or photograph of the chromosomes of a particular cell.
- (Greek, idios = one's own + pathos = suffering) Term used clinically to describe a condition which is unexplained (obscure, unknown cause) or has no other clinical or biochemical associated abnormality.
- (More? Abnormal Development)
- An acronym for IntraCytoplasmic Sperm Injection, An in vitro fertilization procedure in which a single spermatozoa is injected directly into an oocyte; this procedure is most commonly used to overcome male infertility problems.
- An acronym for intrahepatic bile duct
- (ICV, Bauhin's valve) Gastrointestinal tract muscular region (sphincter) lying at the junction between the ileum and the cecum. Function is to prevent reflux of colonic contents into the ileum. Named after Gaspard Bauhin (1560-1624), a Swiss botanist, anatomist, and physician, thought to be the first to describe the ileocecal valve.
- (More? Intestine Development | Gastrointestinal Tract Development)
- (Greek, eilein = to twist) Gastrointestinal tract region forming the distal part of small intestine (bowel) and also the longest (adult 3.5 m length) part anatomically between the jejunum and large intestine. In the embryo, forms as a midgut loop initially attached to the yolk sac and during the embryonic period then lies herniated to the ventral abdominal wall.
- (More? Intestine Development | Gastrointestinal Tract Development)
- (immunization) Clinical term describing the process of inducing immunity to an infectious agent by administering a vaccine. There are several different viruses that can impact upon normal development and associated with the genital tract.
- (more? Viral Infection)
- The term used to describe the process of conceptus invasion of the uterus endometrium (epithelium and underlying stroma) by the blastocyst (conceptus). This process follows conceptus adplantation (attachment) to the endometrium. Abnormal implantation is where this process does not occur in the body of the uterus (ectopic) or where the placenta forms incorrectly. In humans, implantation occurs during the second week of development.
- Statistical term referring to the proportion of the developmental or postnatal population who contract a condition or disease during a specified time period. Postnatally, this reflects the number of new cases of disease over a given time period usually 1 year.
- Previous term for retained products of conception where part of the placenta or fetal membranes remains within the uterus.
- (Latin, incus = anvil) One of the three ossicles (bones) of the middle ear (incus - malleus - stapes) that convert mechanical vibration into fluid movement within cochlea. The incus and the malleus embryonically form initially as a single structure from [Meckel's cartilage, later formation of a joint separates the two bones.
- (More? Hearing - Middle Ear Development)
- (therapeutic abortion) A surgical, pharmaceutical or other medical procedure used to end a pregnancy.
induced pluripotent stem cell
- (IPS cell) A reprogrammed adult stem cell to form an embryonic stem cell, from which tissues or whole animals can develop.
- Developmentally, the term is used to describe the process by which one cell population influences the development of neighbouring cells. Clinically or medically, the term is used to describe the process of artificially inducing labour.
- (More? Birth)
- (IH) One of the most common skin birthmarks appearing as a benign vascular neoplasm, not noted at birth but developing in the neonate and later postnatally. There are several known risk factors: female sex, white non-Hispanic race/ethnicity, and preterm birth. Though described as benign, a recent study has statistically linked these skin anomalies with low birth weight (LBW).
- (More? Integumentary Abnormalities | Abnormal Development | Birth - Low Birth Weight | PMID 18940356)
- (contagious disease) A bacterial, viral or fungal organism that is transferred from one organism to another by four main methods of transmission (contact, vehicular, airborne or vector). Contagiousness refers to the ease of transmission of the infective agent.
- The number of cells (pathogens) required that are required to infect a host and is typically measured in postnatal organisms. A recent study has shown that human pathogens using local action do have lower infective doses, but are not less virulent than those using distant action.
- Shigella and Giardia lamblia require about 10 cells to start an infection.
- Vibrio cholera and Staphylococcus aureus require about 103–108 cells cells to start an infection.
- (IE) An infectious disease of the heart, caused by a blood borne bacteria (Staphylococcus aureus or Streptococcus sp.). The infection can lead to cardiac damage including destruction of valve tissue.
- Anatomical term meaning below, beneath or lying below, a relative anatomical term.
- Reproductive term meaning not fertile, therefore unable to produce offspring. Infertility can be due to many different causes (genetic, environmental, unknown) and also associated with many systems (germ cell formation, endocrine abnormalities, abnormalities of the reproductive tract).
- (More? Genital System - Abnormalities | Human Abnormal Development | Spermatozoa Development | Oocyte Development | Fertilization | Week 1)
- (philtrum) Anatomically the surface midline vertical groove in the upper lip. Embryonically formed by the fusion of the frontonasal prominence (FNP) with the two maxillary processes of the first pharyngeal arch. Cleft palate (primary palate) occurs if these three regions fail to fuse during development. Fetal alcohol syndrome is also indicated by flatness and extension of this upper lip region.
- The uterus funnel-shaped initial segment of uterine tube (oviduct or Fallopian tube) opening into peritoneal cavity and connected to the ampulla. The peritoneal opening sitting over the ovary.
- The anatomical pathway for male testes descent from the abdominal cavity (fetal) into the scrotum.
- (More? Genital - Male Development)
- A glycoprotein hormone is secreted by the corpus luteum and placenta and regulates pituitary follicle stimulating hormone (FSH). The hormone acts in negative feedback regulation of FSH during pregnancy. Measurement of Inhibin A levels is also used as a second-trimester maternal serum marker for Down syndrome.
- A glycoprotein hormone is secreted by early antral follicles during the luteo-follicular transition of the menstrual cycle and regulates pituitary follicle stimulating hormone (FSH). In humans, during the early follicular phase high inhibin B concentrations allow the selection of a single follicle by decreasing the FSH serum levels.
- A fatal neural tube defect of initiation of neural tube closure at the level of the brain.
- (More? Lecture - Ectoderm Development | PMID 19379086)
- (axon initial segment) Neuron cell body (soma) specialized cellular subdomain at the beginning of the axon, which during neuronal development excludes somatodendritic proteins from the axon and helps maintain neuronal polarity. This cytoplasmic region also contains unique cytoskeletal proteins (βIV spectrin and ankyrin G) involved in clustering voltage-sensitive sodium channels (Nav) at high density to enable action potential spike initiation and propagation.
- (More? Lecture - Neural Development)
inner cell mass
- (embryoblast) In an early mammalian embryo, at the blastocyst stage a small group of inner cells that will eventually grow into the embryo itself and subsequently into the adult. The remainder of cells that form the wall are the trophoblast cells.
inner phalangeal cells
- In the cochlea a single row of cells, that along with and three rows of outer phalangeal cells (Deiter's cells), are the hair cell supporting cells.
inner pillar cells
- Within the organ of Corti cells arranged in rows and form a boundary between the single row of inner hair cells and three rows of outer hair cells. These cells have surface-associated microtubule bundles.
- (Greek, isthmus = narrow passage) Term used to describe an anatomical narrowing in a structure or tube.
- (insula, insulary cortex, insular lobe) Neural term describing the cerebral cortex structure located deep within the lateral fissure between the temporal lobe and the frontal lobe.
- A protein hormone, produced by specialized cells of the pancreas, that regulates glucose uptake; a signal for the absorptive state; promotes the synthesis of glycogen and inhibits its breakdown.
- (More? Endocrine - Pancreas Development)
- (Latin, in = on, tegmen = a roof, covering) term used to describe the skin and its associated structures.
- (IAS) The wall (septum) that develops between the two atria in heart (cardiac) development. In the embryo, this septum develops as a sequence of mesenchymal structures bridging the left and right atrial opening (primary atrial foramen) forming a primary and secondary atrial septum.
- A cytokine that interferes non-specifically with the reproduction of viruses.
- (IFNalpha) cytokine used to treat several malignant and nonmalignant diseases, especially hepatitis C.
- (IFE) Term used to describe regions of the cellular (keratinocytes) outer layer of skin, the epidermis, lying between hair follicles. The keratinocyte epidermal cells are an ectoderm derived tissue.
internal auditory meatus
- (internal acoustic meatus, IAM) An anatomical canal in which CN VII and CN VIII ganglia reside and pass through to the brainstem. This bony canal lies between the posterior surface of the petrous pyramid and the bony labyrinth within the dense petrous bone. Also associated clinically with the site where acoustic neuromas may occur.
International Classification of Diseases
- (ICD) The World Health Organization's classification used worldwide as the standard diagnostic tool for epidemiology, health management and clinical purposes. This includes the analysis of the general health situation of population groups. It is used to monitor the incidence and prevalence of diseases and other health problems. Within this classification "congenital malformations, deformations and chromosomal abnormalities" are (Q00-Q99) but excludes "inborn errors of metabolism" (E70-E90).
- (More? International Classification of Diseases | Abnormal Development | Stillbirth and Perinatal Death | WHO ICD-10 | WHO ICD online | History PDF)
- The part of the cell cycle in which the chromosomes are not condensed and the cytoplasm is not dividing.
- (More? Mitosis)
- (Leydig cell) Alternative name for Leydig cell found within the male gonad (testis). A cell that is involved in androgen (testosterone) production.
interstitial cells of Cajal
- (ICC) Neural cells located in the gastrointestinal tract (enteric nervous system) located within the smooth muscle wall (tunica muscularis) that act as electrical pacemakers to coordinate muscular slow wave contraction propagation. There is some evidence which suggests rather than neural crest, that these cells are mesenchymal (like gastrointestinal smooth muscle) in origin. There is also species variablity in plexus formation. In humans, interstitial cells of Cajal (ICC) myenteric plexus (ICC-MP) forms first, then intramuscular (ICC-IM) and deep muscular plexus (ICC-DMP) which are not fully differentiated at birth.
interstitial cell stimulating hormone
- (ICSH, gonadotropin, lutropin, Interstitial Cell Stimulating Hormone, ICSH) Glycoprotein hormone releasd from anterior pituitary hormone that acts on the gonad and has a role in male and female reproduction. In male, stimulates testis interstital cell (Leydig cell) production of testosterone. In female, increase in concentration during the menstrual cycle triggers ovulation (release of the oocyte).
- The form of cartilage growth which occurs from within during development and leads to an increase of cartilage mass. The second form of cartilage growth is appositional growth, on the surface, and occurs mainly in the adult.
- (cornual pregnancy) A form of ectopic pregnancy, less common than tubal pregnancy and occurs in 2 to 4% of all ectopic pregnancies. The gestation develops in the uterine portion of the fallopian tube lateral to the round ligament.
- (More? Ectopic Implantation)
intrahepatic bile duct
- (IHBD) These ducts in the liver transport bile secreted from hepatocytes to the hepatic duct. The cells that line the IHBD are biliary epithelial cells generated from bipotent hepatoblasts around the portal vein.
- (IVS) The cardiac wall (septum) that develops between the two ventricles in heart (cardiac), this process is called ventricular septation. In humans, this septation process begins in week 5 of development the ventricular wall initially has two separate components; a superior membranous septum and an inferior muscular septum.
- Term used in musculoskeletal joint development, refers to the initial site of higher cell density at the position of future joints.
- (More? Joint Development)
- (bowel) Term used to describe the midgut and hindgut portion of the gastrointestinal tract running from after the stomach to the anus. This can also be anatomically subdivided into the small intestine (small bowel) and the large intestine (large bowel).
- (Hirschsprung's Disease, aganglionic colon, megacolon, congenital aganglionic megacolon) Gastrointestinal tract abnormality due to a lack of enteric nervous system (neural ganglia) in the intestinal tract responsible for gastric motility (peristalsis). In general, its severity is dependent upon the amount of the GIT that lacks intrinsic ganglia, due to an earlier developmental lack of neural crest migration into those segments. Historically, Hirschsprung's disease takes its name from Dr Harald Hirschsprung (1830-1916) a Danish pediatrician (of German extraction).
intestinal immune system
- System consists of gastrointestinal tract functional regions and cells including: Peyer's patches, isolated lymphoid follicles, cryptopatches and mesenteric lymph nodes.
- An embryonic or fetal infection initially of the amniotic fluid by a range, and often combination of, usually bacterial or viral pathogens. These infections can be more common with premature rupture of fetal membranes (PROM) and can be from genital tract organisms such as; group B streptococci, Chlamydia trachomatis, Neisseria gonorrhoeae, mycoplasmas, aerobic Gram-negative bacilli (coliforms) and facultative and anaerobic endogenous organisms (peptococci, peptostreptococci, and Bacteroides). The other route of infection is trans-placental transfer of specific pathogens such as; Treponema pallidum, Listeria monocytogenes, Toxoplasma gondii, trypanosomes, and plasmodia.
- (More? Human Abnormal Development)
- (IAI) Clinical term describing an inflammation within the amniotic fluid, can be detected as an elevated amniotic fluid interleukin (IL)-6 concentration, and can be associated with an intra-amniotic infection. Has also been shown to be a risk factor for preterm delivery (within 48 h) associated with combined placenta previa and vaginal bleeding.
- (More? PMID 20146660)
intracytoplasmic sperm injection
- (ICSI) An in vitro fertilization procedure in which a single spermatozoa is injected directly into an oocyte, this procedure is most commonly used to overcome male infertility problems.
- The "horseshoe-shaped" space (cavity) that forms initially in the third week of development in the lateral plate mesoderm that will eventually form the 3 main body cavities: pericardial, pleural, peritoneal. The intra-embryonic coelom communicates transiently with the extra-embryonic coelom.
- (IFT) process by which cilia containing microtubules are formed on cells. Recent research has shown an important roles for cell cilia in different systems during embryonic development.
intrahepatic bile ductule
- (canals of Hering) The gastrointestinal tract liver ducts located between the bile canaliculi and interlobular bile ducts. Histologically, located near the outer edge of a classic liver lobule as a simple cuboidal epithelium lined partially by cholangiocytes and hepatocytes.
- 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
- The term used to describe the process of replacement of a membranous mesenchyme with bone by osteoblasts (bone-forming cells). Mesenchymal cells (osteoprogenitor cells) differentiate into osteoblasts at the initial sites of ossification (ossification centre). Occurs in skull (mandible, maxilla, cranial vault) and clavicle. The majority of the skeleton is formed by ann alternative process of bone formation on a cartilaginous template, endochondral ossification.
- The time in between the beginning of labor and delivery at birth (parturition).
- (More? Birth)
- Term means lying within the uterus, usually referring to within the cavity of the uterus body rather than the uterine tubes.
- (IUD) A clinical material used in preventing implantation, and therefore pregnancy. The mani role of the device is to effect spermatozoa as they pass through the uterine cavity. The other roles of the device may be to: generate an inflammatory response, increase local production of prostaglandins to inhibit implantation, increase oocyte motility in the uterine tube, and inhibit spermatozoa motility in the uterine cavity.
(More? Medline Plus - Birth Control)
intrauterine growth restriction
- (IUGR, intrauterine growth retardation, fetal growth restriction) Term used to descibe clinically a fetus that has not reached its growth potential because of genetic or environmental factors. Abnormal development measured as less than 10th percentile for gestational age, not easy to detect before 32 weeks. This poor fetal growth can have fetal, placental or maternal causes.
- An ultrasound processing method of volume analysis for the visualization of fluid-filled fetal structures such as; heart chambers, vessel lumen, stomach, gallbladder, renal pelvis, and the bladder. Post-processing inverts the gray scale of the volume voxels showing the normally anechoic structures in 3D or 4D renderings. This technique has been used to identify cardiac anomalies.
- (Latin, vitro = glass) In a test tube, used to describe any process that does not occur in its natural environment (in vivo). In development, often associated with In Vitro Fertilization (IVF).
- (More? In Vitro Fertilization)
in vitro fertilization
- (IVF) A number of different techniques or procedures that involves fertilization outside of the body or medical assistance with fertilization. The resulting embryos are then transferred back into the woman's uterus through the cervix.
in vitro maturation
- (IVM, in vitro maturation of human oocytes) A term used to describe a range of techniques for developing ovarian follicles and oocytes outside of the body.
- (More? In Vitro Maturation | Assisted Reproductive Technology | Ovary Development | Oocyte Development | Fertilization | Week 1)
- (Latin, vivo = life) Term used describe any process that occurs in its natural (normal) environment.
in vivo fertilization
- The natural biological mechaism of fertilization that occurs within the body.
- (More? Fertilization)
- Drugs that increase the force of cardiac contraction by acting on the autonomic nervous system.
- General term describing when something turns in upon itself. Used to describe the uterine changes that occur following pregnancy, a process of tissue catabolism of the uterus.
- (Greek, ioeides = violet) An element named for the color of its vapour. It is an essential element required for the synthesis of thyroid hormone, which in turn is required for normal neural development.
- A lack of oxygen in a tissue or organ due to decreasd blood flow by any mechanism (obstruction, narrowing or damage to blood vessels). Leads to hypoxia in the tissue.
islets of Langerhans
- A small cell clusters spread throughout the exocrine pancreas with an endocrine (hormonal) function.
- (More? Endocrine - Pancreas Development)
- A member of a group (isoflavones) of plant compounds with structural similarity to human 17β estradiol. In the diet these can found in soy and red clover products and may exert modest hormonal effects in women, for example a small increase in breast density in premenopausal women.
- (IL) A rare (1 per 22 000 births) situs anomaly where there is a normal heart position (left-sided heart, levocardia) and a dextro position (right-side) of the abdominal viscera.
- (Greek, iso = same + tropos = a turning) Meaning to have the same properties in all directions.
- (I-band, Greek, iso = same + tropos = a turning) Skeletal muscle histology term, describing the light banding pattern formed by sarcomere organisation between the dark anisotropic bands (A-bands).
- Term used in clinical imaging techniques, such as computed tomography, where an equal resolution in the x, y, and z axes, results in voxels that are cubic in shape.
- (Greek, isthmos = a narrow passage, a land-bridge, a connecting band) A term used to describe anatomical structures with a similar physical structure. Uterine isthmus is the region between the uterine body (corpus) and the cervix.
- An acronym for IntraUterine Device, a clinical material used in preventing implantation, and therefore pregnancy.
- (More? intrauterine device)
- An acronym for IntraUterine Growth Restriction or Retardation, described as less than (<) 10th percentile for gestational age, not easy to detect before 32 weeks. It is thought that a combination of genetic effects and environmental programming (uterine nutritional, oxygenation, endocrine factors, etc.) may have a role in low birth weight and future health problems.
- An acronym for Intra-Uterine Insemination using donated sperm.
- Acronym for In Vitro Fertilization, a procedure that involves medical intervention in the normal fertilization process. There are currently many different ways in which fertilization may occur using these clinical techniques. For example, removing eggs from a woman's ovaries, fertilizing them outside her body, then transferring back into the woman's uterus through the cervix.
Izumo sperm-egg fusion protein 1
- (IZUMO1, Japanese, Izumo = a Japanese shrine to marriage) A spermatozoa protein identified as key in the process of spermatozoa-oocyte fusion. A 350 amino acid (Mr 38958 Da) protein of the Ig superfamily and a single-pass type I membrane protein. The extracellular Ig domain has a putative glycosylation site, not required for its function.
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. 2017 Embryology I. Retrieved February 26, 2017, from https://embryology.med.unsw.edu.au/embryology/index.php/I
- © Dr Mark Hill 2017, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G