Question

The white rami ________?

1) are found only in the C1-T1 cord segments
2) are unmyelinated
3) carry preganglionic axons to the sympathetic chain
4) carry postganglionic fibers to the periphery

Answer 1

The white rami communicantes are myelinated structures that carry preganglionic sympathetic fibers from the spinal cord to the sympathetic chain ganglia, and they are only associated with segments C1 to T1 of the spinal cord.

Step-by-step explanation:

The white rami communicantes are myelinated structures that connect the central nervous system to the sympathetic chain ganglia. Specifically, they carry the preganglionic axons from the spinal cord to the sympathetic chain. These preganglionic fibers then synapse with ganglionic neurons, which can project to various target effectors through different pathways, including the unmyelinated gray rami communicantes, which carry postganglionic fibers.

Contrary to the white rami, the gray rami communicantes are composed of unmyelinated axons and are responsible for carrying sympathetic postganglionic fibers from the sympathetic ganglion to the spinal nerve, eventually innervating peripheral targets. The white rami communicantes are only associated with carrying preganglionic fibers, and are found in a limited region of the spinal cord, specifically in the segments from C1 to T1.