GI development pt 1 Flashcards
What is the key stage which forms the ventral body wall and gets the gut within a cavity?
• Embryonic folding
What happens when the embryo folds laterally?
- Creates ventral body wall
* Primitive gut becomes tubular
What happens when the embryo folds cranicaudally?
• Creates cranial a caudal pockets from yolk sac endoderm (beginning of primitive gut development)
What are the three embryonic divisions of the gut?
- Foregut
- Midgut
- Hindgut
What does the division of the regions of the foregut determine?
• It’s blood and nerve supply
Where is only opening in the developing embryo?
• Mid gut
How do the divisions of the gut tube help us?
• Gives us structures for blood supply and lymphatic drainage in the adult
What is the stomatodeum?
• Future mouth
What is the proctodeum?
• Future anus
What is the opening into the yolk sac?
Vitelline duct
What is the internal lining of the gut derived from?
• Endoderm
What is the external lining of the gut derived from? What does it become?
• Splanchnic mesoderm
○ Future musculature
○ Visceral peritoneum
Where is the primitive gut tube found?
• In intraembryonic coelom, suspended by a double layer of splanchnic mesoderm
Give 7 structures found in foregut
- Oesophagus
- Stomach
- Foregut
- Pancreas,liver&gallbladder
- Duodenum(proximaltoentranceofbileduct)
What is the blood supply of the foregut?
• Celiac trunk
Give 6 structures found in midgut
- Duodenum(distaltoentranceofbileduct)
- Jejunum
- Midgut
- Ileum
- Cecum
- Ascendingcolon
- Proximal 2/3 transverse colon
What is the blood supply of the midgut?
- Superior Mesenteric Artery
* Superior Mesenteric Vein
Give 7 structures found in hindgut
- Distal1/3transversecolon
- Hindgut
- Descendingcolon
- Sigmoidcolon
- Rectum
- Upperanalcanal
- Internalliningofbladder&urethra
What is the blood supply of the hindgut?
- Inferior Mesenteric Artery
* Inferior Mesenteric Vein
Why is embryonic distinction important in terms of arterial blood supply?
• Each segment receives blood supply from a distinct branch of the abdominal aorta
What structures receive a mixed blood supply?
• Those which develop close to the junction between foregut and midgut
○ Duodenum
§ Proximal to entry of bile duct - Gastroduodenal & superior pancreaticoduodenal artery
§ Distal to entry of bile duct - Inferior pancreatic duodenal artery (SMA)
○ Pancreas
§ Head - Superior pancreaticoduodenal artery (CT)
§ Inferior pancreaticduodenal artery (SMA)
What are the most important arterial trunks for the GI tract?
- The celiac trunk
- The superior mesenteric artery
- Abdominal aota
- Inferior mesenteric artery
How is the intraembryonic coelom divided?
- By the diaphragm into abdominal and thoracic cavities
* Peritoneum and peritoneal cavity
What is the mesoderm of the gut split into?
- Somatic mesoderm
* Splanchnic mesoderm