Which structure is innervated by postganglionic sympathetic fibers that supply the abdominal and pelvic viscera?

Which structure is innervated by postganglionic sympathetic fibers that supply the abdominal and pelvic viscera?

• A. Heart
• B. Lungs
• C. GI Tract
• D. Skeletal muscle

Answer: (D)

Postganglionic sympathetic fibers to the abdominal and pelvic viscera mostly target smooth muscle and glands to regulate motility, secretion, and vascular tone. These fibers originate in the prevertebral ganglia (such as the celiac, superior mesenteric, and inferior mesenteric ganglia) and travel with arterial plexuses to reach the gastrointestinal tract, as well as kidneys, bladder, and reproductive organs. Skeletal muscle, however, is innervated by somatic motor neurons rather than postganglionic sympathetic neurons. The heart and lungs receive sympathetic input as well, but they are thoracic structures, not part of the abdominal/pelvic viscera. So the GI tract best fits the description.

Postganglionic sympathetic fibers to the abdominal and pelvic viscera mostly target smooth muscle and glands to regulate motility, secretion, and vascular tone. These fibers originate in the prevertebral ganglia (such as the celiac, superior mesenteric, and inferior mesenteric ganglia) and travel with arterial plexuses to reach the gastrointestinal tract, as well as kidneys, bladder, and reproductive organs. Skeletal muscle, however, is innervated by somatic motor neurons rather than postganglionic sympathetic neurons. The heart and lungs receive sympathetic input as well, but they are thoracic structures, not part of the abdominal/pelvic viscera. So the GI tract best fits the description.