Wk3 Endo Flashcards
Term
Definition
primitive gut
The largely undifferentiated embryonic gastrointestinal tract
diverticulum
A pouch from a tube, as in the pouches on the primitive gut which become endodermal organs
head fold
The fold which takes the future heart and head ventrad after the gastrula stage
tail fold
The fold opposite the head fold
lateral folds
The folds on the left and right side of the embryo forming at the same time as head and tail folds
foregut
The gut and its derivatives from the mouth to mid-duodenum. Blood supplied by celiac artery
midgut
The gut from the inferior duodenum to first two-thirds of the transverse colon. Blood supplied by superior mesenteric artery
hindgut
The gut from the last third of the transverse colon to the anus. Blood supplied by inferior mesenteric artery.
oropharyngeal membrane
The membrane that initially seals the anterior end of the gut tube shut at the mouth
cloacal membrane
The membrane that initially seals the posterior end of the gut tube shut at the cloaca
lateral plate mesoderm
The most lateral embryonic mesoderm, consisting of a dorsal leaflet of somatic mesoderm separated by the coelom from the more ventral splanchnic mesoderm
splanchnic mesoderm
The ventral leaflet of lateral plate mesoderm which gives rise to the dorsal mesentery and the connective tissue and smooth muscle associated with the gut. Also gives rise to the heart and blood vessels
somatic mesoderm
The dorsal leaflet of lateral plate mesoderm which gives rise to the body wall, the sternum and ventral dermis. Also gives rise to the pericardium.
coelom
The embryonic cavity in the lateral plate mesoderm which gives rise to the pericardial, pleural and peritoneal cavities.
mesentery
Connective tissue which suspends the primitive gut from the body wall in the body cavity.
neural crest
A highly migratory cell type deriving from the neural folds and generating a diverse array of cell types throughout the body, including the enteric nervous system.
enteric nervous system
The nervous system consisting of neurons with their cell bodies in the gut. Derived from the neural crest, it controls peristalsis.
pharynx
The early, undivided future trachea and esophagus
alpha-fetoprotein
A serum albumin-like protein made by the yolk sac and fetal liver.
peritoneum
The visceral cavity inferior to the diaphragm
retroperitoneal
Lying dorsal to the dorsal wall of the peritoneum.
allantois
A diverticulum of the primitive gut which becomes incorporated into the umbilicus. In the embryos of birds and reptiles, it stores nitrogenous waste.
umbilicus
The connection between the fetus and the placenta, covered by a derivative of the amnion, incorporating the yolk sac, allantois and connecting stalk. The umbilical arteries and vein run through it.
urorectal septum
The septum which divides the cloaca into the urogenital sinus and rectum and divides the cloacal membrane into the urogenital membrane and anal membrane generating the perineum.
urogenital sinus
After division of the cloaca, the urogenital cavity, later contributing to bladder and urethra
cloaca
The transient common vestibule for products of the kidneys, gut and gonads. An adult structure in birds and reptiles.
stenosis
Abnormal narrowing of a channel.
atresia
Absence through degeneration.
fistula
An abnormal passage or channel.
