Question

multiple choice 2 points

the parasympathetic division of the autonomic nervous system originates in the

brain stem and lower region of the sacral spine
brain and lower region of the sacral spine
sacral and lumbar spine
brain stem and thoracic spine

Explanation:

Identify the division of the autonomic nervous system

Using the Autonomic Nervous System knowledge point

• The autonomic nervous system is divided into the sympathetic and parasympathetic divisions.
• The sympathetic division is known as the thoracolumbar outflow because its preganglionic fibers emerge from the thoracic and lumbar regions of the spinal cord.
• The parasympathetic division is known as the craniosacral outflow because its preganglionic fibers emerge from the brainstem and the sacral region of the spinal cord.

Determine the origin of the parasympathetic division

Using the Parasympathetic Cranial Outflow knowledge point

• The cranial component of the parasympathetic division originates in the brainstem, with preganglionic fibers traveling via cranial nerves III, VII, IX, and X.
• The sacral component originates in the lateral gray horns of spinal cord segments S2 through S4 (the lower region of the sacral spine).
• Therefore, the parasympathetic division originates in the brainstem and the lower region of the sacral spine.

Evaluate the given options

• Option 1: brain stem and lower region of the sacral spine — This matches the craniosacral origin of the parasympathetic division.
• Option 2: brain and lower region of the sacral spine — This is too broad, as the origin is specifically in the brainstem (cranial nerve nuclei), not the entire brain.
• Option 3: sacral and lumbar spine — This is incorrect; the lumbar region is associated with the sympathetic division.
• Option 4: brain stem and thoracic spine — This is incorrect; the thoracic region is associated with the sympathetic division.

Answer:

• brain stem and lower region of the sacral spine (Correct answer)
• brain and lower region of the sacral spine
• sacral and lumbar spine
• brain stem and thoracic spine