Small & Large Intestines Flashcards
What are the regions of the small intestine?
Duodenum, jejunum, ileum
What are the regions of the large intestine?
Cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal
Blood supply of the foregut
Celiac trunk
Blood supply of the midgut
Superior mesenteric artery
Blood supply of the hindgut
Inferior mesenteric artery
What does the superior mesenteric artery supply?
Midgut
What organs are in the midgut?
Jejunum, ileum, cecum, appendix, ascending colon, transverse colon
Where will the superior mesenteric artery arise from?
Abdominal aorta at level of L1
Name seven branches of the superior mesenteric artery
- Inferior pancreaticoduodenal artery
- Middle colic artery
- Right colic artery
- Ileocolic artery
- Appendicular artery
- Jejunal arteries
- Ileal arteries
What does the middle colic artery supply?
Transverse colon
What does the right colic artery supply?
Ascending colon
What does the ileocolic artery supply?
Cecum
Blood supply of transverse colon
Middle colic artery
Blood supply of ascending colon
Right colic artery
Blood supply of cecum
Ileocolic artery
Veins of the abdomen mirror arteries and drain into…
superior or inferior mesenteric veins
Superior mesenteric vessels have 15-18 branches for…
jejunum and ileum
Superior mesenteric vessels unite to form loops called ___ that give rise to ___
loops called arterial arcades that give rise to vasa recta
What vessel drains jejunum and ileum?
Superior mesenteric vein
The superior mesenteric vein unites with ___ to form ___
unites with splenic vein to form portal vein
Superior mesenteric vessels are surrounded by…
superior mesenteric plexus
What are the sympathetic and parasympathetic innervations of superior mesenteric vessels?
Sympathetic: T8-T10 (greater and lesser splanchnic nerves)
Parasympathetic: Vagus nerve
Intestines are held in place in relation to organs and abdominal walls by…
principle mesentery
Where is the root of the mesentery?
Duodenal junction/flexure (left side of L2) to ileocolic junction (right side of SI joint)
What are lacteals?
Specialized lymphatic vessels in intestinal villi of the jejunum and ileum that absorb fat
Mesenteric lymph nodes drain to…
superior mesenteric lymph nodes
Where will lacteals drain through?
Juxta-intestinal, mesenteric, and superior central lymph nodes in principle mesentery
Terminal ileal lymph branches drain to…
ileocolic nodes along ileocolic artery
Where in the small intestine are Peyer patches found?
Ileum lymphoid tissue nodules
T8-10 sympathetic fibers innervate…
small intestines via superior mesenteric plexus
Greater, lesser, and least splanchnic nerves provide sympathetic innervation to…
small intestines
Where will sympathetic fibers innervating the small intestines synapse?
Celiac and superior mesenteric ganglia
What provides parasympathetic innervation to the small instestines?
Posterior vagal trunks
Where will posterior vagal trunks parasympathetic fibers synapse?
Postsynaptic neurons in intestinal wall
Name the components of the large instestines
Cecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anal canal
What are epiploic (omental) appendices?
Small fatty projections off the large intestines
What are teniae coli?
Three distinct longitudinal bands of muscle beginning at the base of appendix
What are haustra?
Sacculations of colon wall between teniae coli
Where is Toldt fascia? What is contained within it?
Between mesocolon and retroperitoneum (large intestines)
CT containing lymphatic channels
Which part of the large intestines is the blind pouch?
Cecum
The right lower quadrant of the cecum sits where in relation to the skeleton?
Iliac fossa
What is inferior to the junction of terminal ileum and ileocecal orifice/valve?
Cecum
What is the vermiform appendix? Where is it? What does it contain?
Blind diverticulum located on posteromedial aspect of cecum containing lymphoid tissue
Ascending colon is continuous with…
cecum on the right side of abdomen
Where does the ascending colon ascend to?
Right lobe of liver
Where does the ascending colon end?
Right colic flexure (hepatic flexure)
Where is the ascending colon in relation to the peritoneum?
Secondarily retroperitoneal
Where is the right paracolic gutter?
Wide space between ascending colon and lateral abdominal wall
What is the longest and most mobile part of large instestines?
Transverse colon
Where does the transverse colon begin and end?
Right colic flexure to the left colic flexure (splenic flexure)
What attaches the splenic flexure to the diaphragm?
Phrenicolic ligament
The transverse colon will usually land at the level of…
umbilicus
Where is the descending colon in relation to the peritoneum?
Secondarily retroperitoneal
Where is the left paracolic gutter?
Narrow space lateral to the descending colon
Where does the descending colon begin and end?
Left colic flexure to left iliac fossa
What attaches the sigmoid colon to the pelvic wall?
Sigmoid mesocolon
What is the fold of peritoneum surrounding the vermiform appendix?
Mesoappendix
Where does the sigmoid colon begin and end?
Descending colon to rectum (S3)
Where is the rectum?
Within the true pelvis
What artery supplies the cecum?
Ileocolic artery, a terminal branch of superior mesenteric artery, branches into the appendicular artery
What artery supplies the ascending colon and right colic flexure?
Right colic artery from superior mesenteric artery
Which arteries supply the transverse colon?
Middle colic artery and marginal artery
What is the marginal artery?
Anastomotic artery between right colic artery, middle colic artery, left colic artery, and sigmoid arteries
It parallels and extends the length of the colon, supplying the transverse colon
Veins of the cecum, ascending colon, right colic flexure, and transverse colon drain into…
superior mesenteric vein
The inferior mesenteric artery is a branch of…
abdominal aorta
Descending and sigmoid colon make up the…
hindgut
The inferior mesenteric artery arises at around what level?
L3
What does the inferior mesenteric artery supply?
Descending and sigmoid colon (hindgut)
What arteries branch from the inferior mesenteric artery?
- Left colic artery
- Sigmoid arteries
- Superior rectal artery
Which arteries supply the descending and sigmoid colon?
- Left colic artery
- Sigmoid arteries
- Superior rectal artery
The inferior mesenteric vein drains into… then…
splenic vein then hepatic portal vein
Ileocolic, right colic, and middle colic lymph nodes drain along arteries to…
superior mesenteric lymph nodes
Innervation of ascending and transverse colon
Superior mesenteric nerve plexus provides sympathetic and parasympathetics
Same as small intestines
Sympathetic innervation of colon
Lumbar splanchnic nerves to inferior mesenteric plexus and superior hypogastric plexus
Parasympathetic innervation of colon
Pelvic splanchnic nerves (S2-S4) to inferior hypogastric plexus