Question

Describe the parts of a spinal nerve and their functions (pp. 426-427).

A) Spinal nerves consist of a single part responsible for motor functions.
B) Spinal nerves consist of three parts: the sensory root, motor root, and ganglion.
C) Spinal nerves have two parts, the dorsal and ventral root, which are responsible for sensory and motor functions.
D) Spinal nerves consist of the central root responsible for integrating sensory and motor functions.

Answer 1

Spinal nerves consist of a dorsal root for sensory functions with a ganglion housing sensory neuron cell bodies, and a ventral root for motor functions with neurons in the ventral gray matter of the spinal cord. These roots merge to form a spinal nerve that transmits both sensory and motor information.

Step-by-step explanation:

Spinal nerves are crucial components of the nervous system and they consist of two primary parts: the dorsal root and the ventral root. These roots serve different but complementary functions. The dorsal root, which contains only sensory neurons, enters the spinal cord and has an enlargement called a dorsal root ganglion where the sensory neuron cell bodies are located. The sensory neurons are responsible for transmitting sensory information from the skin, muscles, and other sensory organs to the spinal cord.

On the other hand, the ventral root is made up exclusively of motor neurons, which project from the ventral gray matter of the spinal cord to muscles and other effector organs. These motor neurons are key in executing motor functions, allowing for bodily movements and responses.

Together, the dorsal and ventral roots merge to form the spinal nerve, which carries both sensory and motor information. Each spinal nerve connects to the spinal cord at a specific vertebral level, ensuring that sensory input is processed and motor output is delivered to the correct part of the body.