Chapter 2 Flashcards
Neurons
the fundamental units of the brain and nervous system
What is the function of the cell body?
Contains mechanisms to keep the cell alive
What is the function of dendrites?
It branches out of the cell body to receive electrical signals from other neurons and the axon, or nerve fiber
What is the function of the axon?
It is filled with fluid that conducts electrical signals.
What is the resting potential of neurons?
-70 mV
Action potential
a temporary shift (from negative to positive) in the neuron’s membrane potential caused by ions suddenly flowing in and out of the neuron.
Propagated response
Once the response is triggered, it travels all the way down the axon without decreasing in size.
Important properties of the action potential
- Propagated response
- The action potential remains the same size no matter how intense the stimulus is.
- Spontaneous activity.
Refractory period
the interval between the time one nerve impulse occurs and the next one can be generated in the axon
Spontaneous activity
Action potentials that occur in the absence of stimulus from the environment
Neurons are bathed in a liquid solution rich in xx called?
Ions
How are ions created?
When molecules gain or lose electrons, as happens when compounds are dissolved in water
The solution outside the axon of a neuron is rich in …?
Positively charged sodium Na+ ions
The solution inside the axon is rich in…?
Positively charged potassium K+ ions
Permeability
The ease with which a molecule can pass through the membrane
