BIOL 171 Lecture Notes - Lecture 8: Nissl Body, Axon Hillock, Cranial Nerves
Document Summary
Nervous tissue controls and integrates all body activities within limits that maintain life general functions: communication between brain and body control body functions. 3 basic functions sensing change brain must know what is happening in body interpreting, remembering change brain learns that pain is bad reacting to change brain returns body to homeostasis. Nerve: bundle of nerve cells (axons of neurons) Somatic sensory fibres (send msgs from sensory receptors to cns) motor fibres (send msgs from cns to muscles, glands) Sympathetic fight or flight heart rate, breathing rate, blood pressure increase. Enteric network of sensory, motor neurons within the wall of the gi tract functions independently of ans and cns controls gi function. Neurons (nerve cells) functional unit of the nervous system electrically excitable (able to produce nerve impulses/ap) Parts: cell body (high concentration of cytoplasm) nucleus cytoplasm with usual organelles plus: Schwann cells surround pns axons form around axons in pns separated by nodes of ranvier.
