Question

the skeletal muscles are innervated by ______.

a spinal nerves and cranial nerves
b spinal nerves only
c cranial nerves only
d spinal nerves and autonomic nerves
e cranial nerves and autonomic nerves

Explanation:

Identify the target tissue and its control

Using the Muscle Innervation knowledge point
Skeletal muscles are voluntary muscles controlled by the somatic nervous system. They require neural stimulation to contract.

Analyze the nervous system pathways

Using the Spinal Nerves and Cranial Nerves knowledge points

• Spinal Nerves innervate skeletal muscles of the limbs and trunk below the neck.
• Cranial Nerves innervate skeletal muscles of the head and neck (e.g., facial expression, mastication, and eye movements).
• Autonomic nerves innervate cardiac muscle, smooth muscle, and glands, not skeletal muscle.

Evaluate the given options

• A: Correctly identifies both spinal and cranial nerves as the sources of skeletal muscle innervation.
• B & C: Incorrect because they exclude one of the major groups of nerves that innervate skeletal muscles.
• D & E: Incorrect because autonomic nerves do not innervate skeletal muscles.

Answer:

• (A) spinal nerves and cranial nerves (Correct answer)
• (B) spinal nerves only
• (C) cranial nerves only
• (D) spinal nerves and autonomic nerves
• (E) cranial nerves and autonomic nerves