Neurons/Parts Of A Neuron

Neuron

a nerve cell; the basic building block of the nervous system

Dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

Axon

the extension of a neuron ending in branching terminal fibers, through which messages pass to other neurons

Myelin Sheath

a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses

Action Potential

neural impulse; a brief electrical charge that travels down an axon. The action potential is generated by movement of positively charged atoms in & out of channels in the axon's membrane

Threshold

level of stimulation required to trigger a neural impulse

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Neurotransmitters

chemical messengers that reverse the synaptic gaps between the neurons. when released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse

Types Of Neurotransmitters

1. Acetylcholine

2. Dopamine

3. Serotonin

4. Norepinephrine

5. GABA

6. Glutamate

Soma

the cell body responsible for maintaining the life of the cell

Glial Cells

cells that provide support for neurons

-deliver nutrients

-produce myelin

-cleans up waste products

Acetylcholine

enables muscle action, learning & memory

Dopamine

influences movement, learning, attention, & emotion

Serotonin

influences mood, hunger, sleep, & arousal

undersupply can lead to depression

Norepinephrine

helps control alertness & arousal

GABA

a major inhibitory neurotransmitter

undersupply linked to seizures, tremors, insomnia

Glutamate

a major excitatory neurotransmitter, involved in memory

too much can lead to seizures or migraines, some people avoid MSG inter foods

Afferent Neurons

a neuron carrying info from senses to the CNS

Efferent Neurons

transports messages from CNS to muscles of the body