Splenius capitis innervation is which of the following?

Splenius capitis innervation is which of the following?

• A. Dorsal rami spinal nerves
• B. Ventral rami spinal nerves
• C. Accessory nerve
• D. Phrenic nerve

Answer: (A)

Splenius capitis is an intrinsic back muscle, and its nerve supply comes from the dorsal (posterior) rami of the spinal nerves. These dorsal rami provide motor innervation to the deep back muscles and sensory innervation to the skin of the back, reflecting the segmental, intrinsic arrangement of this muscle group. The ventral rami supply most of the muscles of the anterior and lateral trunk and limbs, not the deep neck extensor muscles like the splenius capitis. The accessory nerve targets the trapezius and sternocleidomastoid, not the splenius capitis, and the phrenic nerve innervates the diaphragm. So the dorsal rami are the correct innervation.

Splenius capitis is an intrinsic back muscle, and its nerve supply comes from the dorsal (posterior) rami of the spinal nerves. These dorsal rami provide motor innervation to the deep back muscles and sensory innervation to the skin of the back, reflecting the segmental, intrinsic arrangement of this muscle group. The ventral rami supply most of the muscles of the anterior and lateral trunk and limbs, not the deep neck extensor muscles like the splenius capitis. The accessory nerve targets the trapezius and sternocleidomastoid, not the splenius capitis, and the phrenic nerve innervates the diaphragm. So the dorsal rami are the correct innervation.