abdominal organs and blood supply: mid and hindgut

superior mesenteric artery

supplies the midgut

• branches off the ventral surface of the abdominal aorta directly below the celiac trunk

• Branches

  • Middle colic a.

    • Supplies transverse colon.

  • Right colic a.

    • Supplies ascending colon.

  • Ileocolic a.

    • Supplies distal ileum, cecum, appendix and 1st part of ascending colon.

  • Multiple branches to the jejunum and ileum.

midgut organs

• 2nd half of duodenum

• Jejunum

• Ileum

• Cecum

• Appendix

• Ascending colon

• Transverse colon

cecum

found in LRQ

• responsible for absorption of water from substances that are passing from the ileum into the large intestine

appendix

found in LRQ

• described as a vestigial organ that has some immune function

• storage for bacteria to aid in digestion

McBurney’s Point

point at which people often feel pain when experiencing discomfort from their appendix

• midpoint of a line drawn from umbilicus to ASIS

left colic flexure

Junction between the transverse colon and descending colon

• End of superior mesenteric supply (transverse) and start of inferior mesenteric supply (descending)

• End of vagus parasympathetic innervation (transverse) and start of pelvic splanchnic parasympathetic innervation (transverse)

• landmark in ULQ

inferior mesenteric artery

branches off the ventral surface of the abdominal aorta approximately 4 cm. above the bifurcation of the aorta into the common iliac aa.

• supplies the hindgut

• branches:

  • Left colic a.

    • Supplying the descending colon.

  • Sigmoid aa.

    • Descending and sigmoid colon.

  • Superior rectal a.

    • Proximal rectum

    • Has important anastomoses with the middle rectal a. (off the internal iliac a.) and inferior rectal a. (off the internal pudendal a.) arteries along the rectum.