intro to NS - neural and gilial structure Flashcards
what are the subdivisions of the NS
PNS and CNS
what is the CNS made up of
brain and SC
PNS
somatic and autonomic NS
what is the ANS composed of
para and sympathetic
in the somatic NS what are the components
sensory components in and motor out
one of each axon
component of autonomic NS
2 cells carry info out
synapse between cells
what does the somatic NScontrol
strained muscle for voluntary actions
what is the somatic system composed of
31 spinal nerves
12 CN
what do neurones consist of
cell body
axon
dendrites
what does the cell body contain
nucleus and cellular organelles
what is the membrane potential determined by
concentration of ions inside and out
permeability of the cell membrane to ions
activity of the pumps
what occurs at resting potential
3 Na pumped out 2K pumped In
membrane permeable to K
negative charge on inside of cell
what happens when threshold is reached
action potential generated
sodium ion channel opens - positive charge inside the neurone
what happens after sodium ion channels opened
(depolarisation)
channels shut
potassium channels open, K leaves cell leading to hyperpolarization
how can action potential generation and propagation be blocke
sodium channel blockers no ionic movement
where is the synaptic cleft and purpose
pre synaptic bouton and post synaptic cell
stops electrical conduction beween cells
what gated channels do the presynaptic bouton have
calcium gated
what occurs upon depolsatisaton of the terminal
calcium gated channels opn
influx into terminal
causes movement of vesicles to bind to membrane
neurotransmitter realised into the cleft via exocytosis
diffuses and binds to receptors on post synaptic membrane
what are the receptors called
ligand gated
What are exitatory neurotramisttors
sodium
what are inhibitory neurotransmitters and what does it cause
chloride
hyperpolarization of the cell
what is convergence
when several presynaptic neves synapse to the same post synaptic nerve
divergence?
when one pre synaptic axon synapses to several post synaptic neurones
what is referredpain
pain felt in where it did not originate
how does referred pain occur
receives input from 2 different areas that coverage on the same post synaptic neurone
