A&P Lect 3 part 1
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A&P Lect 3 part 1
difference between afferent and efferent?
- going toward CNS
- going away from CNS
anatomy of a neuron?
dendrite- some- trigger zone- axon- synaptic knob
three fundamental properties of nerve cells?
excitability, conductivity, secretion
function of a neuron's trigger zone?
to sum up local graded potentials
function of ependymal?
CSF production and circulation
function of microglia?
function of oligeodendrocytes?
myelin sheathes for CNS
function of astrocytes?
form scaffolding of CNS
provide nutrients and growth factors to neurons
take up wastes and neurotransmitters
provide frame to direct nerve growth during development and new synapse formation after birth
attach to capillaries to tighter them into a blood- brain barrier
a wrap of cell membrane around an axon that speeds transmission of an action potential and allows axons to regenerate
the action potentials have a skipping
describe nerve regeneration?
old schwann cells produce growth factors that cause the axon to elongate
new schwann cells wrap the axon as it grows
can only occur in peripheral axons
steps leading to an action potential in a neuron?
open channels allow
causing a change in resting membrane potential locally
local changes are
if the sum reaches
, voltage gated sodium channels
types of neurotransmitters?
where are neurotransmitters made?
made in the soma of each neuron
how are they (neurotransmitters) released?
they are discharged from their transport vesicles at the synaptic knob by the interaction with calcium.
how are they (neurotransmitters) they degraded?
diffusion, re-uptake by presyanptic cell, uptake by astrocyte, enzyme degradation
what do they (neurotransmitters) do?
bind to receptors on the membrane of the post synaptic cell
three types of membrane channels involved in routine action potential?
ligand- gated sodium channel
voltage- gated sodium channel
voltage- gated calcium channel
type of membrane protein involved in an adrenergic synapse?
a second messenger membrane protein
one post neuron receives input from three pre-synaptic neurons
three post, synaptic neurons receive input from pone pre-synaptic neuron