Neurons Flashcards
How does an electrical signal move across a neuron?
goes from dendrites, to axon, to axon terminal
What do motor neurons release?
chemical signal for muscles to contract
What are the two parts of nervous system?
central nervous system
peripheral nervous system
Central nervous system
brain, spinal cord
majority is glilal cells
neurons (minority of cells)
Glial cells
set up wiring in nervous system correctly to begin with
makes sure axons are triggered at the correct targets
Peripheral nervous system
sensory and motor neurons
Resting potential
the difference in charge across its membrane when a neuron is not communicating with other cells
~ -70V
What does the resting potential result from?
Leak channels
Sodium potassium pump
Sodium potassium pump
uses active transport to move ions against their concentration gradients
3+ Na (out)
2+ K (in)
*establishes a negative charge overtime
Leak channels
Set resting potential with sodium-potassium pump
Potassium leak channel is the most numerous
Natural gradient favors potassium leaving
Graded potentials
are needed to stimulate an action potential
Ligand gated channels convert chemical signals to electrical signals that creates a difference in charge with ions flowing across the membrane
Electrochemical potentials
are established because of differences in concentration and in charge across a membrane
2 factors!
Action potential
requires a significant electrochemical signal to open voltage gated channels
Primary somatosensory cortex
receives information of touch and pain
mechanosensitive channels sense mechanical stress (pressure) on the membrane
this sensory information from touch moves across left to right in the brainstem where transferred to the next neuron
Threshold value
value that needs to be overcame to generate an action potential
