Question

1. the medical abbreviations cns, pns, and ans refer to divisions of the:

cranial nerves
spinal cord
nervous system
brain

1. the cranial nerves are string - like groups of nerves coming off of the:

spinal cord
cauda equina
brain and brain stem
pia mater

Explanation:

Question 43

To solve this, we recall the definitions of CNS (Central Nervous System), PNS (Peripheral Nervous System), and ANS (Autonomic Nervous System). The CNS includes the brain and spinal cord, the PNS includes nerves outside the CNS, and the ANS is part of the PNS that controls involuntary functions. All these are divisions of the nervous system. Cranial nerves are part of the PNS, the spinal cord is part of the CNS, and the brain is part of the CNS—none of these are the overarching structure that has CNS, PNS, and ANS as divisions.

Cranial nerves are 12 pairs of nerves that originate from the brain and brain stem (not the spinal cord, cauda equina, or pia mater). The spinal cord gives rise to spinal nerves, the cauda equina is a bundle of spinal nerve roots, and the pia mater is a meningeal layer. So cranial nerves come off the brain and brain stem.

Answer:

C. nervous system

Question 44