Dr Ahmed Fathalla Ibrahim SUPERIOR MESENTERIC ARTERY SUPERIOR

Dr. Ahmed Fathalla Ibrahim

SUPERIOR MESENTERIC ARTERY

ILEOCOLIC ARTERY

SUPERIOR MESENTERIC ARTERY SUPPLY: • It is the artery of midgut • It supplies: 1. Duodenum: 2 nd part (below biliary orifice), 3 rd & 4 th parts 2. Jejunum & ileum 3. Cecum & appendix 4. Ascending colon 5. Right 2/3 of transverse colon

SUPERIOR MESENTERIC ARTERY ORIGIN: • It arises as a single branch from the front of abdominal aorta • It lies at the level of lower border of L 1 • Its origin lies behind body of pancreas

SUPERIOR MESENTERIC ARTERY COURSE: • It descends describing a curve with a concavity towards the right • It runs through the root of mesentery of small intestine TERMINATION: • It ends by anastomosing with the ileal branches of ileocolic artery (its own branch)

SUPERIOR MESENTERIC ARTERY RELATIONS: • The artery descends anterior to (crosses) the following structures: 1. Left renal vein 2. Uncinate process of pancreas 3. Third part of duodenum 4. Abdominal aorta 5. Inferior vena cava 6. Right psoas major muscle (+ right ureter) • On its right side (lateral to it): superior mesenteric vein

BRANCHES OF SUPERIOR MESENTERIC ARTERY Inferior pancreaticoduodenal artery: • Runs (as a single or double branches) in the groove between head of pancreas & duodenum • Supplies head of pancreas & duodenum • Ends by anastomosing with superior pancreaticoduodenal artery

BRANCHES OF SUPERIOR MESENTERIC ARTERY Jejunal & ileal branches: • They are 12 to 15 in number • They arise from the left side of artery • They run between the 2 layers of mesentery of small intestine • Each artery divides into 2 branches which anastomose with adjacent branches forming arcades Branches of arcades unite to form 2 nd, 3 rd & 4 th series of arcades. Terminal arcades gives straight end arteries supplying jejunum & ileum • Fewer arcades supply jejunum compared to ileum

BRANCHES OF SUPERIOR MESENTERIC ARTERY Ileocolic artery: • Arise from the right side of artery • Descends downward & to the right (anterior to right psoas major muscle) • Divides into: 1. Superior branch: supplies lower part of ascending colon & anastomoses with descending branch of right colic 2. Inferior branch: divides into the following arteries: • Anterior & posterior cecal • Appendicular (may arise from posterior cecal) • Ileal branches: supply distal part of ileum & anastomose with termination of superior mesenteric artery

BRANCHES OF SUPERIOR MESENTERIC ARTERY Right colic artery: • Arise from the right side of artery • Divides into: 1. Ascending branch: anastomoses with right branch of middle colic artery 2. Descending branch: anastomoses with superior branch of ileocolic artery • Supplies ascending colon & right colic flexure

BRANCHES OF SUPERIOR MESENTERIC ARTERY Middle colic artery: • Arise from the right side of artery • Divides into: 1. Right branch: anastomoses with ascending branch of right colic artery 2. Left branch: anastomoses with ascending branch of left colic artery • Supplies right 2/3 of transverse colon

INFERIOR MESENTERIC ARTERY SUPPLY: • It is the artery of hindgut • It supplies: 1. Left 1/3 of transverse colon 2. Descending colon 3. Sigmoid colon 4. Rectum 5. Upper (endodermal) part of anal canal

INFERIOR MESENTERIC ARTERY

INFERIOR MESENTERIC ARTERY ORIGIN: • It arises as a single branch from the front of abdominal aorta • It lies at the level of L 3 • Its origin lies behind 3 rd part of duodenum

INFERIOR MESENTERIC ARTERY COURSE & RELATIONS: • The artery descends to the left side of abdominal aorta • It lies anterior to left psoas major muscle & left common iliac artery • On its left side (lateral to it): inferior mesenteric vein • Continues in the pelvis as superior rectal artery

BRANCHES OF INFERIOR MESENTERIC ARTERY Left colic artery: • Divides into: 1. Ascending branch: anastomoses with left branch of middle colic artery 2. Descending branch: anastomoses with sigmoid arteries • Supplies: left 1/3 of transverse colon, left colic flexure & descending colon

BRANCHES OF INFERIOR MESENTERIC ARTERY Sigmoid arteries: • • 1. 2. • They are 2 or 3 branches They anastomose with: with Descending branch of left colic artery Superior rectal artery They supply: sigmoid colon

MARGINAL ARTERY

MARGINAL ARTERY • It is formed by the anastomosis between the colic branches of superior & inferior mesenteric arteries • It begins by anastomosis between ileal branches of ileocolic & termination of superior mesenteric artery • It ends by anastomosis between sigmoid branches of inferior mesenteric with superior rectal artery • From the marginal artery, straight end arteries (vasa recta) supply the large intestine