Advanced Sympathetic Innervation of the Abdomen Quiz

Q1. Why are abdominal prevertebral ganglia positioned near major branches of the abdominal aorta?

• They are somatic ganglia supplying abdominal wall muscles
• They are sensory ganglia for cutaneous nerves
• They receive only parasympathetic fibers from the vagus
• Their position facilitates sympathetic distribution along major periarterial plexuses

Q2. Which feature makes sympathetic innervation of the adrenal medulla unusual compared with most abdominal viscera?

• Preganglionic fibers synapse directly on adrenal chromaffin cells
• Postganglionic fibers from the vagus synapse on chromaffin cells
• Pelvic splanchnic nerves provide its principal secretomotor supply
• The adrenal medulla has only somatic innervation

Q3. Why can interruption of a thoracic splanchnic nerve reduce visceral pain as well as sympathetic efferent transmission?

• Pain fibers terminate in prevertebral ganglia and never reach the spinal cord
• All abdominal pain travels only with the vagus nerve
• Splanchnic nerves contain only skeletal motor fibers
• Visceral pain afferents can travel with sympathetic pathways

Q4. Which pathway best describes sympathetic innervation of a typical foregut organ?

• Thoracic splanchnic nerve to celiac ganglion to periarterial postganglionic fibers
• Phrenic nerve to sympathetic trunk to the organ
• Pelvic splanchnic nerve to dorsal root ganglion to the organ
• Vagus nerve to celiac ganglion to somatic motor fibers

Q5. How does sympathetic innervation generally interact with the enteric nervous system?

• It modulates enteric circuits and generally suppresses digestive activity
• It provides voluntary control of intestinal smooth muscle
• It has no relationship with enteric neural circuits
• It completely replaces the enteric nervous system

Q6. Why may upper abdominal visceral pain be referred to thoracic dermatomes?

• Visceral and somatic afferents converge at related thoracic spinal segments
• Upper abdominal organs are directly innervated by thoracic cutaneous nerves
• The vagus nerve becomes an intercostal nerve in the abdomen
• Prevertebral ganglia directly innervate the skin

Q7. What is the functional significance of periarterial sympathetic plexuses in the abdomen?

• They replace all parasympathetic pathways
• They are located only within the spinal cord
• They carry only somatic motor fibers to abdominal muscles
• They distribute postganglionic sympathetic fibers along arterial routes

Q8. Which statement best describes lumbar splanchnic contributions to abdominal autonomic pathways?

• They are branches of the vagus nerve to the stomach
• They provide somatic motor supply to the anterior thigh
• They connect lumbar sympathetic trunks with lower abdominal and hypogastric autonomic plexuses
• They are parasympathetic branches of S2 to S4

Q9. Why do sympathetic preganglionic fibers destined for abdominal prevertebral ganglia not necessarily synapse in the sympathetic trunk?

• They cannot enter the sympathetic trunk
• They can traverse the sympathetic trunk and synapse later in prevertebral ganglia
• They are already postganglionic before reaching the trunk
• They must synapse in dorsal root ganglia

Q10. Which statement best integrates sympathetic innervation of the abdomen?

• Pelvic splanchnic nerves are the principal sympathetic route to all abdominal viscera
• Somatic lumbar plexus nerves replace autonomic pathways in the abdomen
• Thoracolumbar fibers use splanchnic nerves, prevertebral ganglia, and periarterial plexuses to reach abdominal viscera
• Cranial parasympathetic fibers provide all abdominal sympathetic innervation