Midgut Flashcards
what is meant by the midgut
from half way along the duodenum
jejunum
ileum
caecum
appendix
ascending colon
to 2/3rds of the way across the transverse colon
blood to the midgut is from where
superior mesenteric artery - L1 on aorta
what suspends the jejenum and ileum to the body wall
the mesentery
the small intestine is how long
6m
where does the jejenum begin
at the duodeno-jejunal junction (proximal 2/5ths)
where does the ileum start and end
jejenum to ileocaecal junction (distal 3/5ths)
what is the appearance of the jejenum
upper, red
what is the appearance of the ileum
lower, pale
describe the wall of the jejenum
thicker, more plicae circularis
describe the wall of the ileum
thinner, less plicae
which is narrower of the jejenum and ileum
jejenum is wider
describe the mesenteric vessels of the jejenum
1 or 2 arcades, long branches to wall
describe the mesenteric vessels of the ileum
numerous short branches from 3 or 4 arcades
describe the adipose tissue of the jejenum
most near root of mesentery
describe the adipose tissue of ileum
all through mesentery
describe the lymphoid tissue of the jejenum
small amount
describe the lymphoid tissue of the ileum
numerous Peyer’s patches
what is the arterial supply of the jejenum and ileum
from jejenul and ileal branches of the superior mesenteric artery - anastomose to form arcades (branches from left side and run in mesentery)
what is the arterial supply of the distal ileum
ileocolic branch of superior mesenteric artery
where does blood from jejenum and ileum drain
superior mesenteric vein via ileocolic, ileal and jejenal veins
lymph from the jejenum and ileum drains where
local nodes then pre-aortic nodes at root of superior mesenteric artery at L1
autonomic nerve supply of jejenum and ileum from where
superior mesenteric plexus
pain from jejenum and ileum referred where
umbilical region
what is the function of the mesentery
attaches the jejenum and ileum to the body wall and allows passage of blood vessels, nerves and lymph but also allows the intestines to move within the abdominal cavity during digestion
what are the sacculations of the large intestine wall called
haustra
what are the fatty tags of the large intestine called
appendices epiploicae
are there fatty tags on the small intestine
no
what is the function of the appendices epiploicae
fat store - range in size from person to person
what is the teniae coli
longitudinal muscle collected into 3 bands on the large intestine
give 3 differences in wall of small and large intestine
small has no fatty tags//large does
wall of small looks smooth // large has haustra
small is a continuous layer of smooth muscle // large has teniae coli
function of the large intestine
absorb water and electrolytes
store undigested material until expelled from body
where is the caecum found
lies at the base of the ascending colon and sits in right iliac fossa
where does the ileum open into the caecum
at the ileocaecal valve
caecum is covered in
peritoneum
describe the ileocaecal valve
2 folds in opening of ileum - circular muscle of wall of ileum is a more effective sphincter
what are the relations of the caecum
small intestine
psoas
iliacus
what is the arterial supply of the caecum
caecal arteries from ileocolic artery: the terminal brnach of superior mesenteric artery
venous drainage of caecum
ileocolic vein to superior mesenteric vein
lymph drainage of caecum
to mesenteric then superior mesenteric nodes (L1)
autonomic nerves of caecum from
superior mesenteric plexus
the tip of the appendix is most often found
posterior to the caecum
where is the appendix found
1/3 along line from ASIS to umbilicus
does the appendix have a mesentery
yes small mesoappendix mesentery
what are 2 functions of appendix
small bacterial store
contain lymph tissue
what is the arterial supply of the appendix
small appendicular artery (branch of ileocolic) runs in mesoappendix
the appendicular artery is a branch of what
ileocolic artery
what is the venous drainage of the appendix
small vein that drains into the posterior caecal vein
pain from appendix is referred where
umbilicus (T10)
lymph drainage of appendix
to mesenteric then superior mesenteric nodes (L1)
autonomic nerves of appendix
superior mesenteric plexus
how long is the ascending colon and where does it go between
15cm long from caecum to transverse colon
the ascending colon is ____peritoneal
retroperitoneal
what is the point where the ascending colon turns and becomes the transverse colon
hepatic flexure
what supplies the ascending colon
ileocolic and right colic arteries (branches of superior mesenteric artery)
what are the relations of the ascending colon
small intestine
greater omentum
iliacus
iliac crest
quadratus lumborum
right kidney
ilioinguinal and iliohypogastric nerves
venous drainage of ascending colon
ileocolic and right colic veins to superior mesenteric vein
lymph drainage of the ascending colon
superior mesenteric nodes - pre-aortic L1
nerves of ascending colon
ANS from superior mesenteric plexus
where does the transverse colon pass between
right colic (hepatic) and left colic (splenic) flexures
what is the name of the mesentery by which the transverse colon is suspended
transverse mesocolon
what are the relations of the transverse colon
greater omentum
pancreas
small intestine
what is the blood supply of the proximal 2/3 of the transverse colon
from middle colic artery from superior mesenteric
what is the blood supply of the distal 1/3 of transverse colon
left colic artery from inferior mesenteric artery
blood from transverse colon drains where
superior and inferior mesenteric veins
lymph from transverse colon drains where
proximal 2/3: pre-aortic nodes at L1
distal 1/3: pre-aortic nodes at L3
ANS of transverse colon
from superior and inferior mesenteric plexuses
what is the parasympathetic supply of the transverse colon
vagus nerve supplies the proximal 2/3
pelvic splanchnic nerves supply the distal 1/3
describe the arterial arcade that supplies the transverse colon
marginal artery that anastomoses between the right, middle and left colic arteries
