17.1 quiz Flashcards
(36 cards)
What is the PNS
The peripheral nervous system
What does the PNS consist of (3 parts)
- The somatic nervous system
- Autonomic nervous system: parasympathetic and sympathetic division.
What is the CNS
the central nervous system
What does the CNS consist of
The brain and spinal cord.
What is the difference between the CNS and the PNS
PNS is everything but brain and spinal cord,
What are the 3 types of neurons?
- Sensory
- Inter
- Motor
What is a sensory neuron?
A neuron that recognizes external stimuli and converts it to internal electrical impulses.
Where are sensory neurons located?
In clusters in the dorsal root ganglia by the spinal cord. With axons that extend outwards
Where do sensory neurons send impulses
To central nervous system - brain
What are motor neurons
A neuron whose axon indirectly or directly controls effector organs (muscles and glands)
Where are motor neurons located?
In motor cortex (spinal cord)
What are interneurons?
A neuron that transmits impulses from other neurons, or between neurons and CNS.
Where are interneurons located?
In Central Nervous System only.
What are the three parts of a neuron?
Dendrites, axon, axon terminals
What does the dendrite of a neuron do?
Transmit signals from other nerve cells to cell body.
What does the axon of a neuron do?
Transmit signals from cell body to other nerve cells
What does an axon terminal do?
At the end of the axon, sends signal to synapse (space between nerve cells)
What do you call the potential difference across the membrane of a RESTING neuron?
resting potential
How is the resting potential of an axon maintained?
Sodium potassium pumps
How do sodium potassium pumps work?
Actively transport Na+ out of axon and K+ into axon
Why is the axon charged negatively at rest?
Because there are more + ions outside than inside axon
What do you call the rapid change in polarity across an axonal membrane as nerve impulse occurs?
An action potential
What two gated channel proteins are required in an action potential?
Na+ and K+ gates.
What are the steps of an action potential?
Depolarization, repolarization, refractory phase.
