A 21-year-old man receives a penetrating knife wound in the abdomen and is injured in both the superior mesenteric artery and th
e vagus nerve. Which portion of the colon would most likely be impaired by this injury? A. Ascending and transverse colons.
B. Ascending and descending colons.
C. Transverse and descending colons.
D. Descending and sigmoid colons.
E. Transverse and sigmoid colons.
The ascending and transverse colons will be impaired due to injury because Blood from the superior mesenteric artery and parasympathic nerve fibres from the vagus nerve is collected by the ascending and transverse colon.
However, blood from the lower mesenteric artery and parasympathic nerve fibres from the pelvic splanchnic nerve originating from sacral spinal nerves (S2-S4) is provided by the descending and sigmoid colons.
Hence, the correct answer is A. "Ascending and transverse colons".
