Embryology Of GI Tract Flashcards
What are the superior mesenteric artery and vein protected by?
The peritoneum at the root of the mesentery
How do you distinguish small bowel from large bowel?
Strips of muscle called taeniae coli run on external surface of large bowel
What are the fatty appendices that hang of the external surface of the large bowel?
Omental appendices
What are the haustra?
On the large bowel, pillow like indentations
What is the attachment of the large intestine?
Ascending and descending colon retroperitoneal plastered to posterior abdominal wall
Intraperitoneal ( transverse colon and sigmoid colon )
What forms a sling around the junction between the rectum and the anal canal?
Puborectalis fibres create a kink in GI tract which gives some control when walking upright
What is the circular muscle just below the skin in the anal canal?
Subcutaneous help to control defaecation
How does the GI tract begin?
One longitudinal tract running from the mouth to the anus subdivided into foregut, midgut and hindgut growing parallel to the abdominal aorta
Single artery that connects to foregut, midgut and hindgut
What is the developing GI tube attached to?
Attached to back of developing embryo by double layer of peritoneum called the dorsal mesentery/mesogastrium
Connected to posterior abdominal wall
Additional connection to anterior abdominal wall called the central mesentery - only connects the FOREGUT
What part of the developing GI tract is connected to both the dorsal mesentery (posterior wall) and ventral mesentery (anterior wall)
Foregut
How does the foregut start?
A small dilation in the gut tube at 4-6 weeks over to the left hand side - going to become the stomach - has an attachment to the front and to the back
What grows anteriorly as a diverticuli from the stomach?
The liver
What grows posteriorly as a diverticuli from the stomach?
Parts of the pancreas
Where does the liver grow into?
Anteriorly into the ventral mesogastrium along with gallbladder and ventral pancreatic bud
Where does the pancreas grow into?
Mainly posteriorly into the dorsal pancreatic bud but small portion anteriorly into the ventral pancreatic bud
Buds should fuse together
Which is why pancreas spreads across all over abdominal cavity
