preganglionic fibers

Preganglionic fibers are nerve pathways that originate in the central nervous system (brain and spinal cord) and extend to autonomic ganglia, which are clusters of nerve cells outside the brain and spinal cord. These fibers carry nerve signals that initiate involuntary functions like heart rate, digestion, and blood pressure regulation. They release neurotransmitters that activate postganglionic fibers, which then connect to organs and tissues to carry out these responses. Essentially, preganglionic fibers serve as the communication lines that start the process of controlling automatic body functions.