Nervous System Flashcards
Dendrites
highly branched extensions that receive signals from other neurons
Axon
longer extension that transmits signals to other cells at synapses
Axon Hillock
cone-shaped base of an axon
Synapse
a junction between an axon and another cell
Neurotransmitters
chemical messengers
Soma
Cell Body
Synaptic Terminal
passes information across the synapse
Sensory Neurons
Transmit information about each external stimuli such as light, touch, or smell
Interneurons
integrate (analyze and interpret) the information
Motor Neurons
transmit signals to muscle cells, causing them to contract
Glial Cells
Cells that insulate neurons
Where is the concentration of potassium and sodium higher?
Higher sodium outside the cell and more potassium inside the cell.
What energy is used in SP pump?
chemical potential energy
Resting membrane potential
- This is always negative *usually between -50 and -70)
How does a NAK pump work?
the pump moves three sodium ions out of the cell for every two potassium ions it brings in.
Hyperpolarization
an increase in magnitude of the membrane potential
Hypopolarization/Depolarization
easier to do work ; reduction in the magnitude of the membrane potential
(closer to 0)
Action Potential
look the same in all cells ; these are used for impulses ;
Thereshold potential
when it is reached, the sodium channels open and action potential is started.
How does action potential fall?
Potassium leaves so charge goes back down
Refractory Period
The action potential leaves the Na+ channels inactivated and K+ channels activated for a brief time to recharge.
Do axons go in one direction or several?
It’s one direction
Myelin Sheath
speeds up nerves
What do we used voltage gated ion channels for?
To pass signal?
