Hindgut Flashcards
what is meant by the hindgut
distal 1/3 transverse colon
descending colon
sigmoid colon
rectum
anal canal
what is the blood supply of the hindgut
branches of the inferior mesenteric artery (aorta L3)
where does the descending colon span
from left colic flexure (splenic flexure) to pelvic brim where it becomes sigmoid colon
the descending colon is ____peritoneal
retroperitoneal
what is the arterial supply of the descending colon
left colic and sigmoidal branches of inferior mesenteric artery
venous drainage of descending colon is to
inferior mesenteric vein
lymph from descending colon drains where
local nodes then inferior mesenteric pre-aortic nodes (L3)
nerves of descending colon from
inferior mesenteric plexus and parasympathetic from pelvic splanchnic nerves
relations of descending colon
small intestine
greater omentum
left kidney
quadratus lumborum
psoas
femoral and iliohypogastric and ilioinguinal nerves
does the sigmoid colon have a mesentery
yes, attached to posterior pelvic wall by pelvic mesocolon
where does the sigmoid colon span
from descending colon infront of left external iliac artery to 3rd sacral vertebra where it becomes the rectum
relations of sigmoid colon
bladder (males)
uterus and vagina (females)
rectum
sacrum
arterial supply of the sigmoid colon
sigmoid branches of inferior mesenteric artery
venous drainage of sigmoid colon
veins to inferior mesenteric vein
lymph drainage of sigmoid colon
to inferior mesenteric nodes at aorta (L3)
ANS of sigmoid colon from
inferior hypogastric plexus in pelvis
what does the rectum pass between
sigmoid colon at the sacrum (3rd sacral vertebra) to 2cm infront of tip of coccyx where it pierces pelvic floor and becomes the anal canal
blood supply of rectum
- superior rectal artery from inferior mesenteric artery
- middle rectal artery from internal iliac artery
- inferior rectal artery from internal pudendal
the superior rectal artery is a branch of what
inferior mesenteric
the middle rectal artery is a branch of what
internal iliac artery
inferior rectal artery is a branch of what
internal pudendal
the internal pudendal artery is a terminal branch of what
internal iliac artery
describe the venous drainage of the rectum
superior part to portal system via inferior mesenteric vein
middle and inferior veins to internal iliac and internal pudendal
how is the venous drainage of the rectum described
portal - systemic anastomosis: the superior part of the rectum drains to the IMV which goes to portal system whereas the middle and inferior parts drain to local veins in pelvis which will drain to common iliac veins and then IVC so are systemic
lymph drainage of rectum
superior parts to pre-aortic nodes at L3
distal parts to internal iliac nodes in pelvis
nerves of rectum
inferior hypogastric plexus
length of descending colon
25cm
length of sigmoid colon
25-38cm
length of rectum
13cm
arterial supply: foregut
coeliac axis
arterial supply: midgut
superior mesenteric artery
arterial supply: hindgut
inferior mesenteric artery
lymph drainage: foregut
pre-aortic at T12
lymph drainage: midgut
pre-aortic at L1
lymph drainage: hindgut
pre-aortic at L3
pain: foregut
epigastric
pain: midgut
umbilical
pain: hindgut
supra-pubic
what areas have dual blood supply/dual venous drainage
transition areas
what is the blood supply of the duodenum
proximal = foregut (coeliac axis)
distal = midgut (superior mesenteric)
what is the blood supply of the transverse colon
proximal 2/3 = midgut (superior mesenteric)
distal 1/3 = hindgut (inferior mesenteric)
what is the venous drainage of the rectum
upper part = hindgut (inferior mesenteric + portal system)
lower part = pelvic (internal iliac and systemic)
- portal systemic anastomosis
what is the transition point between parasympathetic supply from vagus and pelvic splanchnic nerves
transverse colon
