Mesenteric Vessels, Intestines

Gross Anatomy


Superior Mesenteric Artery and Small Intestine, Inferior Mesenteric Artery and Large Intestine


Anatomy Tables for Today's Topic

Branches of the Superior and Inferior Mesenteric Arteries
Veins
Viscera
Lymphatics
Nerves

Branches of the Superior and Inferior Mesenteric Arteries

Artery Source Branches Supply to Notes
appendicular posterior cecal, anterior cecal or ileocolic no named branches vermiform appendix despite its variable origin, appendicular artery is nearly constant in its course posterior to the terminal part of the ileum
cecal, anterior ileocolic a. may give off the appendicular a. anterior surface of the cecum anterior cecal a. supplies the ileocecal junction
cecal, posterior ileocolic a. may give off the appendicular a. posterior surface of the cecum posterior cecal a. supplies the ileocecal junction
colic, left inferior mesenteric a. ascending br., descending br. descending colon left colic a. anastomoses with the middle colic a and the sigmoid a.to form part of the marginal a.
colic, middle superior mesenteric right br., left br. transverse colon middle colic a. anastomoses with the right colic a. and the left colic a. to form part of the marginal a.
colic, right superior mesenteric (or br. of) ascending br., descending br. ascending colon right colic a. anastomoses with the ileocolic a. and the middle colic a. to form part of the marginal a.
gastroduodenal common hepatic a. supraduodenal aa., retroduodenal aa., posterior superior pancreaticoduodenal a., anterior superior pancreaticoduodenal a., right gastro-omental a. upper duodenum, upper part of the head of the pancreas; greater curvature of the stomach on the right gastroduodenal a. supplies the lowest portion of the foregut and its derivatives
ileocolic superior mesenteric a. colic br., anterior cecal br., posterior cecal br., appendicular a., ileal br. cecum, appendix, terminal portion of the ileum colic br. of the ileocolic a. participates in the formation of the marginal a.
intestinal superior mesenteric a. arterial arches jejunum, ileum intestinal aa. are 12-15 in number and are found in the mesentery
marginal formed by anastomoses of branches of the ileocolic a., right colic a., middle colic a., left colic a., sigmoid a. colic brs. colon an important anastomosis for the large intestine
mesenteric, inferior abdominal aorta at the level of the L3 vertebral body left colic a., sigmoid aa.(2-3), superior rectal a. splenic flexure, descending colon, sigmoid colon, superior part of rectum branches of the inferior mesenteric a anastomose in the marginal artery
mesenteric, superior abdominal aorta at the level of the lower 1/3 of the L1 vertebral body inferior pancreaticoduodenal a., middle colic a., jejunal a., ileal a., right colic a., ileocolic a. inferior part of the head of the pancreas, distal duodenum, jejunum, ileum, cecum, appendix, ascending colon, transverse colon superior mesenteric a. supplies the midgut derivatives; brs. of the superior mesenteric a. participate in formation of the marginal artery
rectal, superior inferior mesenteric a. two unnamed branches superior part of the rectum superior rectal a. is the continuation of the inferior mesenteric a. after the sigmoid brs. are given off; it anastomoses with the middle rectal a. and the inferior rectal a.
sigmoid inferior mesenteric a. ascending br., descending br. sigmoid colon sigmoid aa. are 2-3 in number; they anastomose with the left colic a. to help form the marginal a.

Veins

Vein Tributaries Drains Into Regions Drained Notes
mesenteric, inferior superior rectal v., sigmoid v., left colic v. splenic v. (or the junction of the splenic v. and superior mesenteric v.) gut from the left colic flexure distally (hindgut derivatives) when the inferior mesenteric v.joins the splenic v., it courses lateral to the 4th part of the duodenum
portal v. formed by the union of the superior mesenteric v. and the splenic v.; tributaries: posterior superior pancreaticoduodenal v., right gastric v., left gastric v. divides into right and left branches before entering the liver; into the liver sinusoids all of the gut and its glands portal v. connects with the vena caval drainage at 1) esophagus, 2) rectum, 3) umbilicus, 4) retroperitoneal gut structures; portal v. courses between two capillary beds (gut and liver)
rectal venous plexus no named tributaries superior, middle & inferior rectal vv. rectum and anal canal; anus rectal venous plexus is a site of portal-caval anastomosis
vena cava, inferior formed by the union of the paired common iliac vv; tributaries: lumbar vv. 1-4, right ovarian/testicular v., renal vv., right suprarenal v., right inferior phrenic v., hepatic vv. right atrium all of the body below the level of the respiratory diaphragm the inferior vena cava is longer than the abdominal aorta

Viscera - Alphabetical

Organ/Part of Organ Location/Description Notes
appendix, vermiform terminal portion of the cecum which has a small dead-end lumen vermiform appendix is attached to the posteroinferior surface of the cecum; it is usually located behind the cecum in the right iliac fossa; pain from the appendix projects to McBurney's point on anterior abdominal wall (1/3rd distance along an imaginary line from the anterior superior iliac spine to the umbilicus); it has a complete peritoneal covering and a small mesentery (mesoappendix)
appendix epiploica fat-filled pendants of peritoneum projecting from the visceral peritoneum on the surface of the large intestine there are many appendices epiploices on the large intestine (except the rectum) and none on the small intestine; also known as: omental appendage
ascending colon part of the large intestine that is continuous with the cecum proximally and the transverse colon at the right colic (hepatic) flexure ascending colon is retroperitoneal
cecum first part of the large intestine which is located in the right lower quadrant cecum is continuous with the ileum (small intestine) at the ileocecal valve; it is continuous with the ascending colon distally; it is intraperitoneal but lacks a mesentery; the vermiform appendix is attached to its posteroinferior surface
descending colon part of the large intestine that is continuous with the transverse colon at the left colic (splenic) flexure and the sigmoid colon at the pelvic brim descending colon is retroperitoneal
duodenojejunal junction part of the small intestine where the duodenum is continuous with the jejunum duodenojejunal junction is located in the left upper quadrant; it is suspended by the suspensory muscle (ligament) of the duodenum; the inferior mesenteric v. passes to left side of the duodenojejunal junction
duodenum proximal segment of the small intestine C-shaped; the duodenum has 4 parts: 1st or superior, 2nd or descending, 3rd or transverse, 4th or ascending
haustra multiple pouches in the wall of the large intestine haustra form where the longitudinal muscle layer of the wall of the large intestine is deficient; also known as: sacculations
ileocecal junction point at which the ileum joins the cecum ileocecal valve moderates the flow of intestinal contents from the ileum into the cecum
ileocecal valve a valve that marks the ileocecal junction ileocecal valve is incompetent, not a sphincter; it has superior and inferior lips
ileum most distal part of the small intestine ileum is continuous with the jejunum proximally and terminates at ileocecal junction distally; it is approximately 12 feet in length; it has a thinner wall than the jejunum, lower plicae circulares than the jejunum, more fat in its mesentery than does the jejunum, more complex arterial arcades than the jejunum, shorter arteriae recta than the jejunum
intestine, large part of the intestinal tract distal to the small intestine large intestine is approximately 5 feet long; parts of the large intestine are: cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum; also known as: colon or large bowel
intestine, small part of the small intestine between the stomach proximally and the large intestine distally small intestine is approximately 21 feet long; parts of the small intestine are: duodenum (1 foot long, mostly retroperitoneal); jejunum (8 feet long); ileum (12 feet long)
jejunum part of the small intestine that is continuous with the duodenum proximally (at the duodenojejunal junction) and the ileum distally (no obvious landmark for its termination) jejunum is approximately 8 feet in length; wall of the jejunum is thicker than the wall of the ileum; plicae circulares (circular folds) are more pronounced in the jejunum than in the ileum; mesentery of the jejunum has less fat than that of the ileum; arterial arcades of the jejunum are more simple than those of the ileum; arteriae recta are longer in the jejunum than they are in the ileum
mesentery peritoneum connecting jejunum & ileum to posterior abdominal wall also known as: mesentery of small intestine
mesoappendix peritoneum connecting the vermiform appendix to the mesentery of the small intestine the cecum is retroperitoneal, but the appendix has its own mesentery which contains its blood supply - a clinically relevant detail during appendectomy
omental appendage fat-filled pendants of peritoneum projecting from the visceral peritoneum on the surface of the large intestine there are many omental appendages on the large intestine (except the rectum) and none on the small intestine; also known as: appendix epiploica
right colic flexure junction of the ascending colon and the transverse colon right colic flexure lies anterior to the lower part of the right kidney and inferior to the right lobe of the liver; also known as: hepatic flexure
sigmoid colon part of the distal large intestine located within the lower left quadrant sigmoid colon is continuous proximally with the descending colon at the left pelvic brim; it is continuous distally with the rectum at the level of the 3rd sacral vertebra; it is suspended from posterior abdominal wall by the sigmoid mesocolon
sigmoid mesocolon peritoneum connecting the sigmoid colon to posterior abdominal wall branches of the inferior mesenteric a. approach the sigmoid colon within the sigmoid mesocolon; ascending preganglionic parasympathetic axons course through the sigmoid mesocolon on their route from the pelvis (S2,3,4) to the descending colon
teniae coli band of longitudinal smooth muscle on the surface of the large intestine there are three teniae coli, named according to their position on the transverse colon: tenia omentalis (located at the line of attachment of the omental apron), tenia mesocolica (located at the line of attachment of the transverse mesocolon), tenia libera ("free" tenia - it has no mesenteric attachment obscuring it)
transverse colon part of the large intestine located between the left and right colic flexures transverse colon is continuous proximally with the ascending colon at the right colic (hepatic) flexure; it is continuous distally with the descending colon at the left colic (splenic) flexure; it is suspended from the posterior abdominal wall by the transverse mesocolon
transverse mesocolon peritoneum connecting the transverse colon to the posterior abdominal wall transverse mesocolon represents the fusion of the transverse mesocolon with one layer of the greater omentum in the embryo; it forms the floor of the lesser peritoneal sac

Lymphatics

Structure Location Afferents from Efferents to Regions drained Notes
cisterna chyli between the abdominal aorta and the inferior vena cava anterior to the body of the L1 or L2 vertebra right and & left lumbar trunks; possibly the intestinal trunk thoracic duct all of the body below the respiratory diaphragm; all of the abdominal and pelvic viscera cisterna chyli is an enlargement of the lower end of the thoracic duct; it occurs in about 25% of individuals
intestinal lymphatic trunk left side of the abdominal aorta or between the abdominal aorta and the inferior vena cava near the level of the superior mesenteric artery union of efferent lymphatic vessels from the celiac nodes and superior mesenteric nodes left lumbar trunk or the cisterna chyli/thoracic duct large and small intestines intestinal lymph trunk carries lymph that is rich in fat; drains into the left lumbar trunk (70%), cisterna chyli (25%) or right lumbar trunk (5%)
lateral aortic nodes along the inferior vena cava and abdominal aorta from the aortic bifurcation to the aortic hiatus of the diaphragm common iliac nodes; lymphatic vessels from the posterior abdominal wall and viscera efferents form one lumbar trunk on each side lower limb; pelvic organs; perineum; anterior and posterior abdominal wall; kidney; suprarenal gland; respiratory diaphragm also known as: lumbar nodes; the intestinal trunk drains into to the left lumbar trunk; the lumbar trunks unite to form the thoracic duct/cisterna chyli
lumbar nodes along the inferior vena cava and abdominal aorta from the aortic bifurcation to the aortic hiatus of the diaphragm common iliac nodes; lymphatic vessels from the posterior abdominal wall and viscera efferents form one lumbar trunk on each side lower limb; pelvic organs; perineum; anterior and posterior abdominal wall; kidney; suprarenal gland; respiratory diaphragm also known as: lateral aortic nodes; the intestinal trunk drains into to the left lumbar trunk; the lumbar trunks unite to form the thoracic duct/cisterna chyli
lumbar trunk between the lumbar vertebral bodies and inferior vena cava (right) or aorta (left) at the upper end of the lumbar chain of nodes lumbar (lateral aortic) nodes; the intestinal trunk joins the left lumbar trunk thoracic duct/cisterna chyli left lumbar trunk - left side of the body below the respiratory diaphragm, gut; right lumbar trunk - right side of body below the diaphragm lumbar trunks unite to form the lower end of the thoracic duct; an enlargement of the lower end of the thoracic duct (called the cisterna chyli) occurs in about 25% of individuals, and when it is present, the lumbar trunks drain into it
thoracic duct between the esophagus anteriorly and the thoracic vertebral bodies posteriorly formed by the union of the lumbar lymph trunks, sometimes dilated to form a cisterna chyli junction of the left subclavian v. and the left internal jugular v. all of the body and limbs below the respiratory diaphragm; the left side of the chest, left upper limb and the left side of the head and neck above the diaphragm thoracic duct is the largest lymphatic vessel; it passes through the aortic hiatus on the right side of aorta; it swings to the left side of the esophagus at the T4-T5 intervertebral disc (at the level of the sternal angle)

Nerves

Nerve Source Branches Motor Sensory Notes
splanchnic, greater thoracic neurons in the intermediolateral cell column of spinal cord levels T5-T9; the greater thoracic splanchnic nerve arises by multiple contributions from the sympathetic trunk no named branches celiac ganglion; preganglionic fibers supply the adrenal medulla which releases epinephrine and norepinephrine into the blood pain from the abdominal viscera greater thoracic splanchnic n. passes through the crus of the respiratory diaphragm; postganglionic processes from the celiac ganglion spread down the aorta and distribute with its branches; they innervate the vascular smooth muscle of these vessels and the organs supplied
splanchnic, least thoracic neurons in the intermediolateral cell column of spinal cord level T12 no named branches renal plexus pain from the kidney and suprarenal gland least thoracic splanchnic n. passes through the crus of the diaphragm; it synapses in minute ganglia located in the renal plexus
splanchnic, lesser thoracic neurons in the intermediolateral cell column of spinal cord levels T10-T11; the lesser thoracic splanchnic nerve arises by multiple contributions from the sympathetic trunk no named branches aorticorenal ganglion pain from the kidney and suprarenal gland lesser thoracic splanchnic n. passes through the crus of the respiratory diaphragm; postganglionic processes from the ganglion supply vascular smooth muscle of branches of the renal a. and suprarenal aa.; kidney and suprarenal gland
vagus n. medulla: dorsal motor nucleus (GVE preganglionic parasympathetic); inferior ganglion (GVA); nucleus ambiguus (SVE); superior ganglion (GSA); inferior ganglion(SVA) >auricular br., pharyngeal br., superior laryngeal, superior and inferior cervical cardiac brs., recurrent laryngeal n., thoracic cardiac brs., brs. to the pulmonary plexus, brs. to the esophageal plexus, anterior and posterior vagal trunks SVE: intrinsic muscles of the larynx, pharynx (except stylopharyngeus), and palate (except tensor veli palatini); GVE: smooth muscle of the respiratory tree & gut (proximal to the left colic flexure), heart; secretomotor: mucous glands of the larynx, respiratory tree, pharynx and gut; secretomotor to digestive glands GSA: skin of the external auditory meatus; GVA: viscera of head, neck, thorax & abdomen proximal to the left colic flexure; SVA: taste from the epiglottis also known as: CN X, 10th cranial nerve; the vagus n. passes through the jugular foramen to exit the posterior cranial fossa; vagus means "wanderer" in reference to its extensive distribution to the body cavities
aorticorenal ganglion preganglionic sympathetic via the lesser thoracic splanchnic n. brs. to the renal plexus vascular smooth muscle of the brs. of the renal aa. pain from the kidney, suprarenal gland, upper ureter a sympathetic ganglion; located above or near the origin of the renal a. from the abdominal aorta
celiac ganglion preganglionic sympathetic axons arrive via the greater thoracic splanchnic n. postganglionic sympathetic axons distribute via the celiac plexus along brs. of the celiac trunk vascular smooth muscle of the brs. of the celiac trunk pain from the stomach, liver & biliary system, spleen, upper half of the duodenum & pancreas a sympathetic ganglion; usually 2 celiac ganglia are located on the abdominal aorta at the origin of the celiac trunk; brs. of the vagal trunks pass through the celiac ganglion without synapsing
mesenteric ganglion, inferior preganglionic sympathetic axons from the intermesenteric plexus and the 2nd lumbar splanchnic n. contributes to the inferior mesenteric plexus; contributes to the superior hypogastric plexus vascular smooth muscle of brs. of the inferior mesenteric a. pain from descending colon and sigmoid colon; pain from upper rectum a sympathetic ganglion; located on the abdominal aorta at the origin of the inferior mesenteric a.; may be a series of small, indistinguishable ganglia rather than a single large one
mesenteric ganglion, superior preganglionic sympathetic axons from the celiac plexus contributes to the superior mesenteric and intermesenteric plexuses vascular smooth muscle of brs. of the superior mesenteric a. pain from the lower half of the pancreas and duodenum, jejunum, ileum, cecum, appendix, ascending colon and transverse colon a sympathetic ganglion; located on the abdominal aorta at the origin of the superior mesenteric a.
myenteric ganglia preganglionic parasympathetic via anterior and posterior vagal trunks (gut proximal to the left colic flexure) and pelvic splanchnic nn. (gut distal to the left colic flexure) postganglionic parasympathetic via many short fibers smooth muscle of the gut wall none minute ganglia located within the myenteric plexus; parasympathetic terminal ganglia
submucosal ganglia of the gut preganglionic parasympathetic arrive via branches of the anterior and posterior vagal trunks (gut proximal to the left colic flexure) and pelvic splanchnic nn. (gut distal to the left colic flexure) postganglionic parasympathetic via many short fibers secretomotor to glands in the mucosa of the gut none terminal parasympathetic ganglia; parasympathetic terminal ganglia; also known as: Meissner's plexus
preaortic ganglia splanchnic nn. plexuses to abdominal and pelvic viscera vascular smooth muscle of vessels that supply abdominopelvic viscera pain from abdominopelvic viscera also known as: collateral ganglia which include the celiac ganglion, aorticorenal ganglion, superior mesenteric ganglion and inferior mesenteric ganglion; preganglionic parasympathetic axons of vagal trunk origin pass through the preaortic ganglia but do not synapse there
esophageal plexus right and left vagus (X) nn.; thoracic visceral brs. of the sympathetic trunk anterior and posterior vagal trunks preganglionic parasympathetic axons from the vagus n. supply smooth muscle and glands of the thoracic esophagus and abdominal gut and its derivatives proximal to the left colic flexure; postganglionic sympathetic axons from the thoracic visceral brs. supply vascular smooth muscle in the esophageal vessels vagus: GVA from the esophagus and abdominal gut proximal to the left colic flexure; thoracic visceral brs.carry pain from the esophagus during development of the gut, the stomach and esophagus rotate 90° to the right with the result that the left and right vagus nerves mix in the esophageal plexus and emerge as anterior and posterior vagal trunks
hypogastric n. superior hypogastric plexus inferior hypogastric plexus supplies vascular smooth muscle of the pelvic viscera pain from the pelvic viscera paired; hypogastric n. lies inferior to the common iliac vessels; it contains postganglionic sympathetic axons
hypogastric plexus, inferior hypogastric nn. and sacral splanchnic nn. (postganglionic sympathetic axons); pelvic splanchnic nn. (preganglionic parasympathetic axons from the ventral primary rami of spinal nerves S2-S4) contributes branches to: uterine/vaginal plexus, vesical plexus, prostatic plexus sympathetic: supplies vascular smooth muscle of vessels supplying the pelvic viscera; parasympathetic: supplies smooth muscle of the pelvic viscera pain from the pelvic viscera; general visceral afferent from the pelvic viscera inferior hypogastric plexus lies between the pelvic viscera and the pelvic wall
hypogastric plexus, superior intermesenteric plexus and lumbar splanchnic nn. (postganglionic sympathetic axons) hypogastric nn. (right and left) vascular smooth muscle of the pelvic viscera (sympathetic) pain from the pelvic viscera; general visceral afferent from the pelvic viscera superior hypogastric plexus is the continuation of the intermesenteric plexus; it crosses the pelvic brim
iliohypogastric n. lumbar plexus (ventral primary ramus of spinal nerve L1) lateral and anterior cutaneous brs. muscles of the lower abdominal wall skin of the lower abdominal wall, upper hip and upper thigh iliohypogastric n. receives a contribution from T12 in approximately 50% of cases

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Some of the material presented in these tables is contained in the book:
MedCharts Anatomy by Thomas R. Gest and Jaye Schlesinger
Published by ILOC, Inc., New York. Copyright 1995.

Content of these tables has been edited for use in this course by Patrick W. Tank, Ph.D.
Copyright 2007, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences.

Unauthorized use is prohibited.