Question

question 6
the posterior (dorsal) ramus:
a supplies motor and sensory neurons to the thoracic area
b supplies motor and sensory neurons to skin and muscles of the back
c supplies motor and sensory neurons to the vertebral column
d is a plexus arising from the lumbar area

Explanation:

The posterior (dorsal) ramus of a spinal nerve branches off from the main nerve trunk. It specifically innervates (supplies) the skin and muscles of the back. The thoracic area is mainly innervated by intercostal nerves (from the anterior rami in most thoracic regions). The vertebral column has multiple components, but the key function of the posterior ramus is related to the back's skin and muscles. A plexus (like the lumbar plexus) is a network of nerves formed by anterior rami, not the posterior ramus.

Answer:

B. supplies motor and sensory neurons to skin and muscles of the back