The ear receives its sympathetic innervation from which spinal levels?

The ear receives its sympathetic innervation from which spinal levels?

• A. T1-T4
• B. T5-T9
• C. T10-T12
• D. C1-C4

Answer: (A)

The ear’s sympathetic supply comes from the first four thoracic spinal levels. Preganglionic neurons reside in the intermediolateral cell column from T1 to T4, their axons exit the spinal cord and enter the sympathetic trunk, and they ascend to synapse in the superior cervical ganglion. From there, postganglionic fibers ride along the carotid arteries into the head, reaching the ear to provide vasomotor control and other sympathetic functions. Because the head and neck sympathetic outflow originates from T1–T4, that’s why these levels are the source for ear innervation. Levels lower down (T5–T12) or higher up in the cervical region don’t supply the head’s sympathetic pathways in the same way.

The ear’s sympathetic supply comes from the first four thoracic spinal levels. Preganglionic neurons reside in the intermediolateral cell column from T1 to T4, their axons exit the spinal cord and enter the sympathetic trunk, and they ascend to synapse in the superior cervical ganglion. From there, postganglionic fibers ride along the carotid arteries into the head, reaching the ear to provide vasomotor control and other sympathetic functions. Because the head and neck sympathetic outflow originates from T1–T4, that’s why these levels are the source for ear innervation. Levels lower down (T5–T12) or higher up in the cervical region don’t supply the head’s sympathetic pathways in the same way.