OB-R
leptin hormone receptor found in many different tissues. Receptor belongs to class I cytokine receptor family. These act through intracellular JAKs (Janus kinases) and STATs (signal transducers and activators of transcription) pathways.
(More? leptin)
obstetric fistula
childbirth injury caused by several days of obstructed labour without prompt medical intervention. Blood supply is interrupted to surrounding tissues (bladder or rectum) leading to tissue death generating a hole or fistula. (More? End Fistula Organisation)
abnormality of forearm with Duane syndrome of eye retraction. In humans, due to mutation in SALL4 gene on chromosome 20q13.13-q13.2.
(More? Kohlhase J, Heinrich M, Schubert L, Liebers M, Kispert A, Laccone F, Turnpenny P, Winter RM, Reardon W. Okihiro syndrome is caused by SALL4 mutations. Hum Mol Genet. 2002 Nov 1;11(23):2979-87.)
omphal
(omphalo) used as a prefix to terms with an umbilical relationship when namimg these structures and associated abnormalities.
omphalocele
a congenital malformation with herniation of abdominal contents through the umbilicus, which can be covered by a membrane. Not to be confused with gastroschisis (para-umbilical hernia) or hypoplasia of abdominal muscles, skin-covered umbilical hernia.
(More? GIT Abnormalities)
omphalomesenteric artery
(vitelline artery) Embryonic artery carrying blood to the yolk sac from the embryo.
(More? Heart Notes)
omphalomesenteric duct
(vitelline duct) A connection through the umbilicus between the yolk sac to the primitive gut that disappears at 8 to 9 weeks of gestation. Many developmental abnormalities are associated with failure of the vitelline duct to resorb, most commonly Meckel's diverticulum.
(More? GIT Abnormalities | GIT Movies | Pubmed omphalomesenteric duct malformations)
(vitelline veins) Embryonic vessels providing the venous pole input into the heart from the umbilicus.
(More? Heart Notes)
(Greek, oo = egg) term used to describe the egg or ovum formed within the ovary (female gonad).
(More? Week 1 - Oogenesis)
(Greek, oo = egg + genesis = origin, creation, generation) process of diploid oogonia division and differentiation into an haploid oocyte (egg) within the ovary (female gonad). Mammalian meiosis will only be completed within the oocyte if fertilization occurs.
(More? Week 1 - Oogenesis)
oogonia
(Greek, oo = egg) diploid germ cells within the ovary (female gonad) which provide the primary oocytes for oocyte (egg) formation. In humans, all oogonia form primary oocytes within the ovary before birth.
(More? Week 1 - Oogenesis)
oophorus
(Greek, oo = egg + phorus = carrying, egg-bearing) cumulus oophorus, used to describe the granulosa cells within the follicle that tether or link the oocyte to the wall of the follicle.
(More? Week 1 - Oogenesis)
(Greek, orthos = straight or rigid, ptera = wing) Order of insects including grasshoppers, locusts, katydids and crickets. Grasshopper neural development has been used as models for mechanisms of neural development.
(More? Other Embryos)
osteoblast
The mesenchymal cells that first differentiate to form the cellular component of bone and produce bone matrix. Osteoblast mature to form osteocytes. Pluripotent mesenchymal stem cells are the common mesenchymal progenitor for several different cell types including: osteoblasts, chondroblasts, muscle, bone marrow stromal cells and adipocytes. Osteoblasts express alkaline phosphatase, collagens and non-collagen bone matrix proteins (osteocalcin) and hormone receptors (PTH, 1,25-dihydroxyvitamin D3, estrogen, glucocorticoids).
Cells that remove bone (bone resorption) by enzymatically eroding the bone matrix. These cells are blood cell (monocyte-macrophage) in origin and fuse to form a multinucleated osteoclast. These cells allow continuous bone remodelling and are also involved in calcium and phosphate metabolism. The erosion cavity that the cells lie iwithin and form is called Howship's lacuna. Osteoclasts express a number of proteolytic Matrix MetalloProteinases (MMPs) including MMP-9, MMP-10, MMP-12 and MMP-14.
(More? Musculoskeletal Development - Bone |Cardiovascular System - Blood)
osteocyte
The mature bone-forming cell, which form the cellular component of bone and produce bone matrix. These cells differentiate from osteoblasts, mesenchymal cells that first differentiate to initially form bone.
Osterix
(Osx) osteoblast-specific transcription factor required for osteoblast differentiation, which inhibits the Wnt pathway activity.
(More? Bone Development | Molecular Development)
otitis media
fluid in the middle ear accompanied by signs and symptoms of ear infection. Common developmental problem, prolonged or repeated occurance can lead to developmental delay in learning, speech and even damage to the middle ear structures.
(More? Senses Notes | Hearing Abmnormalities)
otocyst
(= otic vesicle) the sensory otic placode which sinks into mesoderm to form spherical vesicle (stage 13/14 embryo) that will form components of the inner ear.
Otx2
paired type homeobox gene identified in many species which has a role in early head and brain development.
(More? OMIM - Otx2)
(OSP, Meissner’s plexus, plexus submucosus externus , Schabadasch plexus) A gastrointestinal tract intrinsic neral network, that is one of the two (inner and outer) lying within the submucosa involved in intestinal secretion and gut motility in large mammals. Smaller animals have only a single submucous plexus.
(More? Gastrointestinal Tract Notes)
A cause of infertility due to problems with egg production by the ovaries.
(More? Week 1 - Oogenesis)
use of ultrasound and/or blood or urine tests to monitor ovarian follicle development and hormone production.
(More? Week 1 Notes | Week 1 - Oogenesis)
ovarian stimulation
use of drugs to stimulate the ovaries to develop follicles/eggs. (More? Week 1 - Oogenesis | Human Menstrual Cycle)
oviduct
(= uterine horn, fallopian tube) anatomical structure which in mammals forms a narrow tube extension from the uterine body opening into peritoneal cavity overlying the ovary. The oviduct is lined with laterally paired and has two layers a mucosa (ciliated and secretory epithelium) and a muscularis (inner circular muscle layer and an outer longitudinal layer)
(More? Week 1 - Oogenesis | Week 1 Notes | Blue Histology - Female Reproductive System)
ovulation
process of release of the oocyte from the mature follicle in ovary. In humans, generally a single oocyte is released from a cohort of several maturing follicles.
(More? Week 1 - Oogenesis | Week 1 Notes)
(oxycephalus) or "tower skull" results from premature coronal suture synostosis. One of several skull deformities (scaphocephaly, oxycephaly, plagiocephaly, trigoncephaly) caused by premature fusion (synostosis) of different developing skull sutures.
(More? Skull Notes | Head Notes)
(Greek, "quick birth") an 8 amino acid peptide hormone released from the maternal posterior pituitary, involved in initiation and maintenance of birth labor by acting on the myometrium.
(More? Normal Development - Birth | Birth Overview )
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Search the NIH Medlineplus Medical Dictionary Type the word that you would like to find. If unsure of spelling, type the first few letters, followed by an asterisk(*). |
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Use this page to access brief definitions of specific alphabetically listed 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 Glossary List: Texts listed on page 1 Reading of each notes section, Department of Anatomy Publications, WWW resources from NCBI, AMA (USA), Office of Rare Diseases (USA), PubMed Medline Dictionaries, MSDS, Merck Manual home edn., NHMRC (Australia). 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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