wk 4 1 bleeding in the gi tract anatomy Flashcards
3 functions of coloin
defence - commensal bacteria
absorption - h20, electrolytes
excretion - stool
which parts of the colon are intraperitoenal/retroperitoneal
intra -caecum ascending - retro transverse - intra descending - retro sigmoidal - intra`
paracolic gutters
part of greater sac of peritoneal cavity (similar to subphrenic/hepatorenal recess)
teniae coli
3 longlitudinal smooth muscls
caecum - distal sigmoid, join at appendix
which flexure - splenic or hepatic lies more superiorly
splenic
mcburneys points corresponds with the appendiceal orrifice, the sorest area in appendicitis, where does it lie
1/3 between right anterior superior iliac spine and umbilicus
sigmoid colon is at risk of twisting round itself, name given and what does it cause
sigmoid volvulus
bowel obstruction
left untreated - risk of infarction
where does the abdominal aorta lie in relation to the vertebral bodies and IVC
vertebral - anterior
IVC - left
what are the 3 midline branches of abdominal aorta, where does each exit thE AORTA
celiac trunk - T12 (foregut)
superior mesenteric - L1 (hindgut)
inferior mesenteric - L3 (hindgut)
lateral branches of abdominal aorta
kidneys/adrenal glands - L1
Gonads - L2
Body wall (posterolateral)
the aorta bifurcates to common iliacs at
L4
jejunal and ileal arteries are similar since they both contain a vasa rectaa and arcades, how do they differ
jejunum - longer vasa rectae (loops)
-larger + fewer arcades (anastamoses)
3 branches of inferior mesenteric artery (l3)
left colic artery
sigmoid arteries
superior rectal artery
marginal arteyr of drummond
arterial anastomoses between IMA and SMA.
allows alternative route if ischaemic
superior rectal artery, a branch of IMA suppplies the proximal half of the anal canal, what supplies the rest
internal iliac artery
splenic vein drains
foregut structures ot hepatic portal
which vein drains blood from midgut/ hinfgut structures
midgut - superior mesenteric vein
hindgut - inferior mesenteric vein
there are 3 areas of anastamosis in the portal-system, which have no valves and blood can flow in both directions, where are these
distal end of oesophagus
skin around umbilicus
anal canal
the distal end of oesophagus is an anastomoses site, where does the inferior/superior part drain into
inferior - hepatic
superior - azygous
caval system
systemic blood flow (vena cava)
t/f epigastric veins drain into caval system
true
t/f para-umbilical veins drain to caval system
false
to hepatic portal along round ligament of liver
which part of the 3 anastomoses drains into the internal iliac veins
inferior ppart of gi tract
causes of portal hypertension, what does it lead to
liver pathology (cirrhosis) tumour
reversal of blood flow
what can cause haematemesis 2
bleeding from oesophageal varices
peptic ulcer in wall of stomach/duodenum