Flashcards in Lower Gastrointestinal Tract Deck (134)
What do you find in the mesentery of the small intestine?
Nerves, blood vessels and lymphatics.
What do you call the permanent folds in the jejunoileum?
What are the strips of longitudinal muscle in the wall of the colon called?
What are the outward bulges of the colon called?
Name the four regions of the colon.
Ascending, transverse, descending, sigmoid.
What does "uncinate" mean?
What do you call the "arches" of arteries in the mesentery?
Where does the superior mesenteric artery arise?
From the aorta, just below the coeliac artery.
Where does the superior mesenteric artery run?
Downwards behind the splenic vein, and in front of the left renal vein, then over the uncinate process of the pancreas and part 3 of the duodenum.
What branches does the superior mesenteric artery give off?
Branches to the pancreas and duodenum, then branches to the mesentery of the jejunoileum, then branches down and to the right in the retroperitoneum (ileocolic towards caecum, right colic to ascending colon), then a branch upwards into the transverse mesocolon (middle colic to transverse colon).
Where does the inferior mesenteric artery arise?
Below the pancreas and duodenum at the level L3.
What are the branches of the inferior mesenteric artery?
The left colic artery (supplies distal 1/3 of transverse colon, and descending colon), sigmoid branches (supply sigmoid colon), and superior rectal artery (supplies upper part of rectum - lower parts of rectum supplied by internal iliac artery).
Which two arteries anastomose to form an arcade in the transverse mesocolon?
Middle colic and left colic arteries.
What do the veins in the GI tract anastomose to form instead of joining the inferior vena cava, and where do they join?
The hepatic portal vein, formed behind the pancreas.
What level is the aortic bifurcation at?
Where does the hepatic portal vein take blood from and to?
Blood from the GI tract, spleen and pancreas, to the liver.
What veins form the portal vein?
Superior and inferior mesenteric veins, and the splenic vein.
What is different about the foregut from the midgut and hindgut during development of the embryo?
The foregut is attached the the abdominal wall by a double fold of peritoneum and the front and at the back (dorsal mesogastrium, and ventral mesogastrium), this allows the momentum to develop when the foregut rotates on its long axis. The midgut and hindgut are only attached to the abdominal wall by a double fold of peritoneum at the back.
Where does the attachment of the ventral mesogastrium end up after rotation of the foregut?
Along the lesser curvature, having swung round to the right.
Where does the attachment of the dorsal mesogastrium end up after rotation of the foregut?
Along the greater curvature, having swung round to the left.
What develops in the ventral mesogastrium?
What develops in the dorsal mesogastrium?
What is the opening called that leads into the lesser sac (omental bursa)?
Epiploic foramen (foramen of Winslow).
In the embryo, what is the midgut continuous with?
The Vitelline duct (yolk stalk), which is later obliterated.
Which artery runs up into the rectus sheath past the arcuate line to supply the rectus abdomens muscles?
Inferior epigastric artery.
What happens at the tip of the 9th costal cartilage?
The external oblique muscles, internal oblique muscles, and transverses abdomens muscles become aponeurotic.
Where is the transpyloric plane?
Along the line drawn between the tips of the 9th costal cartilages.
It is half way between the suprasternal notch and the pubic symphysis.
It is at vertebral level L1.
What's the name of the curved line on the lateral aspect of the six-pack where the muscles become aponeurotic?
Where does the linea semilunaris meet the costal margin?
At the tip of the ninth costal cartilage.