Sympathetic Nervous System

Question 1

3 options to body wall

Answer 1

1. Normal (T1-L2)
2. Ascend (T1-T5) to Cervical Ganglia
3. Descend (T6-L2) to L3-CX1

Question 2

How do the spinal nerves Innervate the head and neck?

Answer 2

• Internal Carotid Nerve/Plexus
• Spinal nerves to symp. ganglia ascend to superior cervical ganglion and then follow Common Carotid Artery to all head & neck (“vessel hoppers”)

Question 3

Options to thorax and abdomen

Answer 3

• Thorax (T1-T5): Sympathetic ganglion to organ
• Abdomen (T6-L2): Pass through sympathetic ganglion without synapsing, synapse in pre-vertebral ganglia (Celiac (T6-T8), Superior Mesenteric (T9-T11), or Inferior Mesenteric(T12-L2))

Question 4

What spinal nerves form the Greater Splanchnic Nerve, the Lesser Splanchnic Nerve, and the Least Splanchnic Nerve and where do these nerves synapse?

Answer 4

• Greater Splanchnic (T6-T8) to Celiac Ganglion
• Lesser Splanchnic (T9-T11) to Superior Mesenteric Ganglion
• Least Splanchnic (T12-L2) to Inferior Mesenteric Ganglion

Question 5

What is the exception to the rule of 2 Neurons?

Answer 5

The nerve to the Adrenal Medulla forms the Greater Splanchnic Nerve but does not synapse at the Celiac Ganglion. Instead, it goes through it, so that only a single neuron innervates the Adrenal Medulla.

Question 6

What ganglia do sympathetic cardiac nerves come from?

Answer 6

Middle Cervical Ganglion to Sympathetic Ganglion at T5