Lecture 1 - Development of the Digestive System Flashcards
Foregut and hindgut form during which type of folding of the embryo
cranial and caudal folding
Endoderm from the dorsal yolk sac is incorporated into the embryo forming the
epithelial lining and the glands that are going to make up the inner most lining of our GI tract
the cranial fold with the oropharyngeal membrane as the hinge joint is incorporated as the embryologic ____
foregut
the caudal fold with the cloacal membrane as the hinge joint is incorporated as the emryologic __
hindgut
epithelial lining and glands of the GI tract
endoderm
During body folding (Week 4), endoderm from the ____ portion of yolk sac is incorporated into the embryo, forming the innermost lining of the primitive gut tube (the epithelial lining and glands of the G.I. tract).
dorsal
During lateral folding, yolk sac endoderm is incorporated as embryonic ___
midgut
forms the smooth muscle and connective tissue of the GI tract
Splanchnic (visceral) mesoderm
when we hear “peritoneum” think
abdomen
the serous membrane lining the abdominal cavity (parietal) & organs (visceral)
peritoneum
a double-layer of peritoneum that suspends an organ from the body wall
(can contain CT, fat, blood vessels, lymphatics, nerves)
mesentery
organs which are completely enclosed in mesentery and connected to wall via mesentery
Intraperitoneal
organ that lies against posterior body wall and is covered with peritoneum on anterior surface only
Retroperitoneal
somatic mesoderm or
parietal (body)
splanchnic mesoderm
visceral or dorsal (organ)
what is holding the midgut to the posterior body wall
dorsal mesentery
Formed via visceral mesoderm layers meeting and fusing in midline
dorsal mesentery
The caudal part of the foregut, the midgut, and major part of the hindgut are suspended from the posterior body wall via the
dorsal mesentery
Extends from lower end of esophagus to cloacal region of hindgut
dorsal mesentery
Divisions of dorsal mesentery:
(4)
Dorsal mesogastrium (greater omentum)
Mesoduodenum
Dorsal mesocolon
Mesentery proper
Dorsal mesentery in region of the stomach
Dorsal mesogastrium (greater omentum)
Dorsal mesentery in region of the duodenum
Mesoduodenum
Dorsal mesentery in region of the colon
Dorsal mesocolon
Dorsal mesentery of jejunal and ileal loops
mesentery proper
Derived from the septum transversum:
ventral mesentery
Mesodermal tissue that gives rise to central tendon of diaphragm and connective tissue in the liver
ventral mesentery
associate ventral mesentery with
foregut
Exists only in region of terminal esophagus, stomach, and upper part of duodenum
ventral mesentery
Liver grows in the mesenchyme of the septum transversum, dividing ventral mesentery into:
______– extends from lower portion of esophagus, stomach, & upper portion of duodenum to liver
____– extends from liver to ventral body wall
Lesser omentum – extends from lower portion of esophagus, stomach, & upper portion of duodenum to liver
Falciform ligament – extends from liver to ventral body wall
Free inferior margin of falciform ligament
Contains obliterated umbilical v.
Round ligament of the liver (Ligamentum teres hepatis)
Free margin of lesser omentum connecting duodenum & liver
Contains portal triad (bile duct, portal v., & hepatic a.)
Hepatoduodenual ligament
bile duct, portal v., & hepatic a. make up what
portal triad
enteric nervous system (no connecting to the brain, operates alone) is derived from
neuroectoderm neural crest cells
run from the pharynx and esophagus all the way down to the proximal half the the duodenum
foregut
run from the the distal half of the dueodenum all the way to the proximal 2/3 of the transverse colon
midgut
run from the distal 1/3 of the transverse colon all the way down out through the anus
hindgut
3 unpaired branches off the abdominal artery
celiac (trunk) artery
Superior mesenteric artery
inferior mesenteric artery
the 3 unpaired branches of the abdominal artery and what they supply
foregut?
midgut?
hindgut?
foregot - celiac trunk a.
midgut - superior mesenteric a.
hindgut - inferior mesenteric a.