Innervation of Splenius capitis.

Innervation of Splenius capitis.

• A. Dorsal rami of the middle cervical nerves (C4-C8)
• B. Intercostal nerves
• C. Thoracodorsal nerve
• D. Long thoracic nerve

Answer: (A)

Splenius capitis is innervated by the dorsal rami of the middle cervical spinal nerves, typically from C4 to C8. These dorsal rami supply the intrinsic back muscles, including the splenius group, enabling actions like head extension, lateral flexion, and rotation. This pattern fits its location in the posterior neck and its segmental innervation. Intercostal nerves go to the intercostal muscles and thoracic skin, the thoracodorsal nerve to the latissimus dorsi, and the long thoracic nerve to the serratus anterior, so they do not innervate splenius capitis.

Splenius capitis is innervated by the dorsal rami of the middle cervical spinal nerves, typically from C4 to C8. These dorsal rami supply the intrinsic back muscles, including the splenius group, enabling actions like head extension, lateral flexion, and rotation. This pattern fits its location in the posterior neck and its segmental innervation. Intercostal nerves go to the intercostal muscles and thoracic skin, the thoracodorsal nerve to the latissimus dorsi, and the long thoracic nerve to the serratus anterior, so they do not innervate splenius capitis.