The white rami communicantes contain what kind of fibers? a. preganglionic parasympathetic, b. postganglionic parasympathetic, c. preganglionic sympathetic, d. postganglionic sympathetic.

Verified step by step guidance

1. Understand the role of the rami communicantes in the autonomic nervous system, which connects the spinal nerves to the sympathetic trunk.
2. Recall that the autonomic nervous system is divided into the sympathetic and parasympathetic systems, each with preganglionic and postganglionic fibers.
3. Identify that the white rami communicantes specifically carry fibers from the spinal cord to the sympathetic trunk.
4. Recognize that preganglionic fibers are myelinated, which gives the white rami their characteristic color.
5. Conclude that the white rami communicantes contain preganglionic sympathetic fibers.

Key Concepts

Rami Communicantes

Rami communicantes are small nerve fibers that connect the spinal nerves to the sympathetic trunk. They are involved in the autonomic nervous system, specifically in relaying signals between the central nervous system and peripheral organs. The white rami communicantes specifically carry preganglionic sympathetic fibers from the spinal cord to the sympathetic ganglia.

Preganglionic vs. Postganglionic Fibers

Preganglionic fibers are the axons of neurons that originate in the central nervous system and extend to a ganglion, where they synapse with postganglionic neurons. Postganglionic fibers then carry signals from the ganglion to the target organs. Understanding the distinction between these two types of fibers is crucial for comprehending the pathways of the autonomic nervous system.

Sympathetic Nervous System

The sympathetic nervous system is a part of the autonomic nervous system that prepares the body for 'fight or flight' responses during stressful situations. It increases heart rate, dilates airways, and inhibits digestion, among other functions. The fibers involved in this system, particularly the preganglionic sympathetic fibers, are essential for initiating these physiological changes.