PSL201Y1 Lecture Notes - Resting Potential, Myelin, Axon Hillock
Document Summary
Cns: brain and spinal cord protected by back-bone and skull necessary for maintenance of homeostasis contains 10^11 neurons contains 10^14 synapses (connections between neurons processing happens here) responsible for everything we perceive, do, feel, and think. Peripheral nervous system: everything else that lies outside the cns functions to connect the cns to the organs (including limbs) divided into the somatic and the autonomic nervous system doesn"t have protection. Input: somatic(muscle), special(hearing, vision, sound, taste), and visceral(blood pressure, how organs are doing) senses (afferent) input to brain and spinal cord. Autonomic output goes through either somatic or autonomic nervous system somatic skeletal muscles. + voluntary movements, stuff that you can control. + control internal environment (ie: cardiac, smooth muscles. + you don"t know when to use the muscle but the brain does. + excitable cells can change membrane potentials (can fire an action potential, a signal) + have connections up to 10,000 other neurons.
