Question

multiple choice 2 points
voluntary motor impulses leave the spinal cord via the ________ of gray matter.
posterior horn
anterior funiculus
anterior horn
posterior funiculus
lateral horn

Explanation:

Identify the functional regions of spinal gray matter

Using the Spinal Cord Functions and Somatic Nervous System Control knowledge points

• The gray matter of the spinal cord is divided into functional regions: posterior (dorsal) horns, anterior (ventral) horns, and lateral horns.
• Sensory information enters the spinal cord dorsally through the posterior horn.
• Motor signals exit the spinal cord ventrally.

Locate voluntary motor neurons

Using the Somatic Nervous System Control knowledge point

• Voluntary motor control is mediated by somatic motor neurons.
• Somatic motor neuron cell bodies reside specifically within the anterior (ventral) horn of the spinal cord gray matter.
• Their axons exit via the ventral root to innervate skeletal muscles.

Evaluate the given options

• posterior horn: Contains cell bodies of interneurons receiving sensory input.
• anterior funiculus: A region of white matter, not gray matter.
• anterior horn: Contains cell bodies of somatic motor neurons for voluntary motor impulses.
• posterior funiculus: A region of white matter, not gray matter.
• lateral horn: Contains cell bodies of autonomic (visceral) motor neurons.

Answer:

• posterior horn
• anterior funiculus
• anterior horn (Correct answer)
• posterior funiculus
• lateral horn