Neurons & Potentials Flashcards
describe a neuron
Send electrical signals throughout the body very rapidly and has direct signaling
rely on ion disequilibrium across the cell membrane to send signals (we call this disequilibrium a potential)
what does neuron structure have
cell body
dendrites
axon
myelin sheaths
axon terminus
axon hillock
nodes of ronvier
what does cell body do for neuron
has all organelles, signals pass down cell membranes
what does dendrites do for neuron
branches that connect with other neurons
what does axon do
carrier from dendrites to terminus
what does myelin sheaths do
insulate, cover surface of axon
what does axon terminus do
neurotransmitter released to go to next neuron
what does axon hillock do
trigger point for neuron
what does node of Ranvier do
used in saltatory conduction which is used to increase speed at which an action potential can pass down the length of the axon
what are the 4 zones of neuron
1) dendrites & cell body- input zone
2) Axon hillock- trigger zone
3) Axon, myelin sheath & nodes of Ranvier- conductive zone
4) Axon terminus- output zone
explain the physiology of neuronal signaling
a disequilibrium must be maintained which is facilitated by Na-K-ATPase pump.
maintains a net negative charge inside the cell membrane which is caused by cation leakage (K+ leaks out, Na+ leaks in) K+ leakage is slightly faster, which sets up the membrane potential.
what does the Na-K-ATPase pump exchange
3 Na+ per 2 K+
this sets up membrane potential
what is membrane potential
the difference in electrical energy across a membrane
changes during graded and action potential
draw and fully label a axon
