Neurons Flashcards
(38 cards)
What are neurons?
Nerve cells
Specialized cells that transmit messages
What are the major regions of neurons
- Cell body - nucleus and metabolic center of the cell
- Processes - fibers that extend from the cell body (Dendrites and axons)
What does the cell body include?
The nucleus and large nucleolus
What does the dendrites do?
They conduct impulses towards the cell body
What doe axons do?
(There is only 1 axon)
It conducts impulses away from the cell body
What is an axonal terminal?
It is the end of an axon, they contain vesicles with neurotransmitters
What is a synaptic cleft?
The gap between adjacent neurons
What is synapse
The junction between nerves (Includes the synaptic cleft)
What is gray matter?
Cell bodies within the white matter of the central nervous system
What is nuclei?
clusters of cell bodies within the white matter of the central nervous system
What is ganglia?
Collections of cell bodies outside the central nervous system
What are the three functional classification of neurons
- Sensory
- Relay
- Motor
What does a sensory neuron do?
It carries impulses from receptors to the CNS
Example: Pain receptors in skin to the CNS
What do relay neurons or interneurons do?
They carry impulses from sensory nerves to motor nerves. They are found in neural pathways in the CNS
What do motor neurons do?
They carry impulses from CNS to effector
In what order would the neurons be used?
- The sensory neuron
- Association neuron
- Motor neuron
What is a bipolar neuron
A neuron with one axon and one dendrite
What is irritability?
The ability to respond to stimuli
What is conductivity
The ability to transmit an impulse
When the plasma membrane is at rest its…
Polarized, fewer positive ions are inside the cell than outside the cell
What is during depolarization?
A stimulus depolarizes the membrane
What happens after depolarization?
The depolarized membrane allows sodium to flow inside the membrane (Sodium has a positive charge Na+)
What does the exchange of ions allow?
It initiates an action potential in the neuron
What allows for potassium ions to be rushed out of the neuron?
The action potential lets sodium ions rush in, repolarizing the membrane