PSL300H1 Lecture Notes - Lecture 19: Central Nervous System, Dorsal Root Ganglion, Enteric Nervous System
Document Summary
Composed of the brain and the spinal cord. Neurons outside the cns make up the peripheral nervous system (pns) Includes all neurons and parts of it outside the cns (cell body could be in spinal cord, etc) Pns comprises the somatic nervous system for controlling voluntary action and skeletal muscle (things you can control) Autonomic nervous system for visceral functions like hr/breathing. Part of autonomic system is the enteric nervous system - controls digestion and movements of the gut - gets input from spinal cord, but can work independently. Most neurons are found in the cns, with 86b (recent figure - used to be 100b) in the brain, and. Enteric nervous system range from 100-600m; pns total is not much more (5b or so) Cns and pns also have cells called glia - support and protect neurons and are about as numerous (before: est that 10x glia than neurons)
