Large Intestine Flashcards
Where does the large intestine extend from?
ileocecal junction to anus
How long is the large intestine?
1.5 m
What is primary function of the large intestine?
convert liquid contents of the ileum into semisolid feces by absorbing water
also involved in sythesis of vitamins requiring bacterial action like vitamin k (blood clotting)
What is the large intestine made up of?
cecum
appendix
colon
rectum and anal canal
What is the cecum?
blind pouch found below ileocecal junction
What does the ileal fold do?
prevent backflow of feces into small intestine
What does the ileal fold surround?
ileal orifice
What does the ileal fold make when it fuses together?
frenula
What is the appendix?
narrow muscular tube which contain lymphoid tissue in its walls
Where does the appendix rise from?
posteromedial aspect of cecum and attaches to mesentery of ileum by mesoappendix
What is the most common position of the appendix?
retrocecal
What is the second most common position of the appendix?
pelvic
What does the colon consist of?
ascending colon
transverse colon
descending colon
sigmoid colon
What does the ascending colon run from?
ileocecal junction to right colic flexure
What does the transverse colon run from?
right colic flexure to left colic flexure
What does the descending colon run from?
left colic flexure to pelvic brim
What does the sigmoid colon run from?
pelvic brim to front of sacrum where it becomes rectum
cecum and appendix are intraperatoneal?
yes
ascending and descending colon are retroperitoneal?
yes
transverse and sigmoid colon lie within the peritoneal cavity?
yes
What are taeniae coli?
three narrow longitudinal bands of muscle seen most prominently in cecum and ascending colon
What is haustra of colon?
sacculations or outpounchings of the colon
What is omental appendices?
small masses of fat which are covered with visceral peritoneum which extend from colon
What is the rectum and anal canal?
terminal portion of large intestine
What is the blood supply to the small and large intestine?
superior and inferior mesenteric artery
What are the branches of the superior mesenteric artery?
inferior pancreaticoduodenal artery Jejunal and Ileal arteries Ileocolic artery Right colic artery Middle colic artery
What does the inferior pancreaticoduodenal artery supply?
pancreas and distal part of duodenum
What does the Jejunal and ileal arteries supply?
jejunum and ileum
What does the ileocolic artery supply?
ascending colon, cecum, and appendix
What does the right colic artery supply?
ascending colon
What does the middle colic artery supply?
transverse colon
What are the branches of the inferior mesenteric artery?
left colic artery
sigmoid arteries
superior rectal artery
What does the left colic artery supply?
descending colon
What does the sigmoid arteries supply?
sigmoid colon
What does the superior rectal artery supply?
rectum and upper part of anal canal
What is so special about the marginal artery?
anastomotic channel which helps prevent bowel infarction because it connects to all the branches and allows astigmatic circulation
What is the vasa recta?
straight terminal branches from marginal artery to large intestine
What is the innervation of the large intestine for the cecum and right 2/3 of transverse colon?
autonomic fibers from superior mesenteric plexus
What is the innervation of the large intestine for the left 1/3 of transverse colon to upper part of anal canal?
autonomic fibers from inferior mesenteric plexus and hypogastric plexus
