descending colon

The descending colon is the continuation of the transverse colon after the left colic flexure, where the colon loses its mesentery.

Gross anatomy

The descending colon measures up to 25 cm in length and is secondarily retroperitoneal. It descends down attached to the left posterior abdominal wall into the left iliac fossa where it continues as the sigmoid colon. Peritoneum covers the anterior and lateral surfaces.

Relations

• anteriorly: loops of small intestine, anterior abdominal wall, greater omentum
• posteriorly: posterior abdominal wall
  • distal descending colon crosses over external iliac and gonadal vessels
• laterally: left paracolic gutter
• medially: left infracolic space

Blood supply

• arterial
  • branches of inferior mesenteric artery
    • descending branch of left colic artery: proximal descending colon
    • sigmoid arteries: distal descending colon
• venous: similarly named veins draining to the splenic vein and portal venous system

Nerve supply

• sympathetic: inferior mesenteric plexus
• parasympathetic: via pelvic splanchnic nerves (S2-S4)

Lymphatic drainage

Lymphatics travel with vessels to the inferior mesenteric group.

Siehe auch:

• Arteria mesenterica inferior
• Colon sigmoideum
• Kolon
• Mesenterium
• peritoneal cavity
• Dünndarm
• left colic flexure
• portal venous system
• Kolon transversum
• sigmoid arteries
• Arteria colica sinistra

und weiter:

• anterior pararenal space
• inframesocolic space