3G. Anatomy of bleeding GI Flashcards
describe the 3 parts of the abdominal organs based on their embryological origins
foregut- oesophagus to mid duodeum/liver, gallbladder,spleen and half of pancreas
midgut- second part of duodeum, 2/3rds of transverse colon, other half of pancreas
hindgut - 1/3rd of transverse colon and anal canal
name the 3 abdominal aorta midline branches
coeliac trunk
superior and inferior mesenteric arteries
name what 3 places the lateral branches on the abdominal aorta supply
kidneys/adrenal glands
gonads- testes/ovaries
body wall
what does the abdominal aorta eventually bifurcate into
common iliac artery - internal and external
which midline branch of abdominal artery comes first
coeliac trunk
which vertebral level does the coeliac artery branch occur
T12
what does the coeliac artery supply
foregut
where is the coeliac trunk in regards to the peritoneum
retroperitoneal
what 3 branches does the coeliac trunk trifurcate into
splenic artery
hepatic artery
left gastric artery
where does the splenic artery have to travel to get to the spleen
along the superior border of the pancreas
describe the spleen in terms of where it is
intraperitoneal organ with left hypochondrium
anatomically related to
- posterior to diaphragm
-anterior to stomach
- inferior to splenic flexure
- medial to the left kidney
which ribs protect the spleen
9-11
do the spleen and liver move with respiration
yes but thats because they are anatomically related to the diaphragm
what vessel supplies the stomach
right and left gastric arteries
right and left gastro-omental arteries
which blood vessels run along the lesser curvature of the stomach
left and right gastric arteries (anastomses)
which blood vessels run along the greater curvature of the stomach
left and right gastro omental arteries (anastomoses)
where does the liver get their blood from
hepatic arteries (left and right) 20/25%
Hepatic portal vein
what are the branches of the superior mesenteric artery
inferior pancreaticduodenal
middle colic
right colic
ileocolic
appendicular
jejunal and ileal
name the branches of the inferior mesenteric artery
left colic
sigmoid arteries
superior rectal arterywh
which artery is a direct continuation of the inferior mesenteric artery
superior rectal artery
which is narrower. The ascending colon or the cecum
ascending colon
what is the left colic flexure also called
splenic flexure
what flexure is more superior and less mobile
splenic flexure (left)
what is the transverse colon suspended by
the transverse mesocolon (anterior border of pancreas)
ascending and descending retro or intra peritoneal
momentarily retroperitoneal
what are paracolic gutters and what are they lined with?
The paracolic gutters are spaces in your abdomen. Imagine two vertical grooves or channels running alongside the sides of your large intestine (colon). One is next to the ascending colon and the other is next to the descending colon
These gutters are lined with a thin layer called the parietal peritoneum, which is a membrane that covers the walls of the abdominal cavity. The main function of these gutters is to help direct the flow of fluids within the abdomen, such as pus, bile, or blood, especially when there’s an infection or injury.
what is identifiable about the sigmoid colon
it is a S shaped loop
where does the sigmoid colon sit in the body
extends from the iliac fossa to the third sacral S3
is the rectum free moving or fixed
fixed
where does the rectum start
S3 vertabra
what is the arterial anastomoses called that is between the branches of the superior and inferior mesenteric arteries
marginal artery of drummond
what blood vessel supplies the hindgut organs
inferior mesenteric artery
where does the hind gut extend to
the proximal half of the anal canal (the pectinate line)
what supplies the remainder of the GI tract after the IMA supplies the hindgut up till half of the anal canal
the internal iliac artery
if a patient is vomiting up blood what could be the cause (2 options)
peptic ulcer in wall of stomach or duodenum
bleeding from the oesophageal varices
what is the sequence of events with the hepatic portal venous system
inferior mesenteric artery gets blood from the hind gut and transports it to the splenic artery (a branch of the coeliac) which gets blood from that and the foregut structures. It then combines with the inferior mesenteric artery which is carrying drained midgut blood to become the hepatic portal vein which takes the blood to the liver to be cleaned. (first pass metabolism) the blood it then taken out the liver by the hepatic veins and given to the IVC which dumps it in the right atrium
how many venous anastomoses are there- describe them
3
distal end of oesophagus
skin and umbilicus
rectum/anal canal
at these sites - distal end of oesophagus
skin and umbilicus
rectum/anal canal
there is a presence of what veins? and what is unique about them
collateral veins - blood can flow both ways either into systemic or hepatic portal venous system. THEY HAVE NO VALVES
in the rectal region, what is present that highlights that blood circulates locally
the venous plexus
superior rectal vein drains into what
inferior mesentery vein
middle and inferior rectal veins connect to what
internal iliac vein
what is portal hypertension
increased BP in portal veins
what pathology causes portal hypertension
cirrhosis
if there is portal hypertension where does blood go
diverted through the collateral veins back into systemic venous system
when blood is diverted through the collateral veins back into systemic venous system due to portal hypertension what does this cause and why
varicose veins (in the collateral veins) as there is much larger volume than usual
