The posterior ramus of a typical spinal nerve innervates the

Deep muscles of the back and the skin of the back.

Explanation:

Spinal nerves are the nerves which originate from the spinal cord of the central nervous system and are involved in the locomotion of the limbs and the trunk of the body.

Each spinal nerve is formed of the axons of the motor neurons (dorsal) and the sensory neurons (ventral root). These root structures unite and split into the dorsal or posterior ramus and the ventral or anterior ramus.

The dorsal ramus supplies the nerves to the dorsal part of the body that is the muscles of the back, dorsal muscles and the skin of the dorsal muscles.

Thus, Deep muscles of the back and the skin of the back is correct.

The posterior ramus of a typical spinal nerve innervates the: deep muscles of the back and the skin of the back. The anterior ramus of a typical spinal nerve innervates the: anterior and lateral trunk and the limbs.

Explanation:

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