Label the white and gray matter components in the figure. 0.08 points eBook Print References Lateral Anterior Posterior Anterior horn funiculus funiculus horn Lateral funiculus Central canal Posterior horn Reset Zoom
18 Label the white and gray matter components in the figure. 0.08 points eBook Print References Lateral Anterior Posterior Anterior horn funiculus funiculus horn Lateral funiculus Central canal Posterior horn Reset Zoom
The Correct Answer and Explanation is:
Here is the correct labeling for the spinal cord cross-section shown in the image:
Top to bottom, left to right (matching arrows to the correct structures):
- Posterior funiculus
- Posterior horn
- Lateral funiculus
- Lateral horn
- Anterior horn
- Anterior funiculus
- Central canal
Explanation
The spinal cord consists of gray matter and white matter, each having specific structural and functional roles. In a transverse section like the one in the image, gray matter appears in an “H” or butterfly shape and is surrounded by white matter.
Gray matter contains neuron cell bodies and is divided into “horns”:
- The posterior horn (dorsal horn) receives sensory input from the body.
- The anterior horn (ventral horn) contains motor neurons that control skeletal muscles.
- The lateral horn (present only in thoracic and upper lumbar regions) contains neurons of the autonomic nervous system.
White matter surrounds the gray matter and contains myelinated axons organized into funiculi (columns):
- The posterior funiculus lies between the posterior horns and carries ascending sensory pathways.
- The anterior funiculus is located between the anterior horns and carries both ascending sensory and descending motor tracts.
- The lateral funiculus, on the side, also carries both ascending and descending tracts for sensory and motor signals.
The central canal, located at the center of the gray matter, contains cerebrospinal fluid and is continuous with the ventricular system of the brain.
Understanding these divisions is critical for diagnosing and treating neurological damage. For example, damage to the anterior horn is associated with motor deficits (as in ALS), while damage to posterior columns affects sensory perception. Accurate labeling of these regions helps medical professionals localize injuries within the central nervous system.
