Flashcards in Development of the GI Tract Deck (26):
Describe the formation of the primitive gut tube.
The gut tube is formed from the endoderm lining the yolk sac which is then enveloped splanchnic mesoderm which is wrapped around the gut tube to form the mesenteries that suspend the gut tube within the body cavity. The mesoderm immediately associated with the endodermal tube also contributes to most of the wall of the gut tube, which is it's self surrounded by the developing coelom as the result of cranial and caudal folding.
Name the 3 embryonic divisions of the gut.
What is the medical term given to the embryonic future mouth?
What is the medical term given to the embryonic future anus?
What does the foregut derive into in adults?
- Liver and gall bladder
- Duodenum (Proximal to entrance of bile duct)
What does the midgut derive into in adults?
- Duodenum (Distal to entrance of bile ducts)
- Ascending colon
- Proximal 2/3 transverse colon
What does the hindgut derive into in adults?
- Distal 1/3 transverse colon
- Descending colon
- Sigmoid colon
- Upper anal canal
- Internal lining of bladder and urethra
What is the arterial blood supply to the foregut?
What is the arterial blood supply to the midgut?
Superior mesenteric artery
What is the arterial blood supply to the hindgut?
Inferior mesenteric artery
Name the 5 branches of the abdominal aorta from cranial to cephalic.
- Celiac trunk
- Superior mesenteric artery
- Renal artery
- Gondal artery
- Inferior mesenteric artery
Name 2 organs of the gastrointestinal system that have mixed blood supply and name their supplies.
1. Duodenum: The proximal portion until the entry of the bile duct is supplied by the celiac trunk, the distal portion to the entry of the bile duct is supplied by the superior mesenteric artery.
2. Pancreas: The superior pancreaticoduodenal is supplied by the celiac trunk, whereas the inferior pancreaticoduodenal is supplied by the superior mesenteric artery.
Describe the development of the intraembryonic coelom.
It begins as one large cavity. It is later divided by the future diaphragm into the abdominal and thoracic cavities.
In which region(s) of the gut tube does the dorsal mesentery provide suspension?
The foregut, midgut and the hindgut
In which region(s) of the gut tube does the ventral mesentery provide suspension?
The foregut only
What is the 'free edge'?
Where the ventral mesentery finishes
Which sac is known as the greater sac?
Which sac is known as the lesser sac?
Which mesentery, dorsal or ventral, forms the greater omentum?
Which mesentery, dorsal or ventral, forms the lesser omentum?
Where is the lesser sac situated, in-front or behind the stomach?
How are the omenta and the greater and lesser sacs formed?
Rotation of the stomach
Name 2 secondarily retroperitoneal organs.
Describe how the trachea and oesophagus form from the foregut.
A respiratory diverticulum forms in the ventral wall of the foregut at the junction with the pharyngeal duct.
A tracheoesophageal septum then forms.
Name glands formed in the ventral mesentery.
- Biliary system