Nervous System

What is CNS and PNS

CNS: the brain and spinal cord, processes info and coordinates responses

PNS: all the nerves outside the brain and spinal cord, carries messages between the CNS and rest of the body

what is sensory afferent and motor efferent

sensory afferent: nerve fibres that carry info to the CNS

motor efferent: nerve fibres that carry info away from the CNS (somatic: voluntary, autonomic: involuntary)

what are the 2 principle cell types that a nervous tissue is made of and what do they do

supporting cells: resemble neurons, unable to conduct nerve impulses, never lose the ablity to divide, different types with different functions

Neurons: conduct nerve impulses

structure of neuron (nerve cell)

cell body: contains nucleus

dendrites: conduct impulses towards cell body

axons: conduct impulses away from cell body

axonal terminals: contain vesicles with neurontransmitters

what does the myelin sheath do

insulates the axon and speeds up nerve impulses, helps nerve impulses travel faster and more effeciently along the axon. If damaged it can cause sclerosis (MS).