Nervous System (Psychology)

Neuron

a nerve cell that receives and transmits information

Dendrites

receive messages from other neurons

Cell Body

contains the nucleus and keeps the neuron functioning

Axon

carries neural impulses away from the cell body

Myelin Sheath

insulates the axon and speeds up neural impulses

Axon terminals

releases neurotransmitters to communicate with other cells.

Synapse

tiny gap between communicating neurons

Neurotransmitters

chemical messengers that carry signal across the synapse

Neural Communication Process

1) dendrites receive a message
2) cell body processes incoming signals
3) Axon carries the electrical impulses
4) Axon terminals releases neurotransmitters
5) Neurotransmitters cross the synapse and bind to receptors to the next cell.

Resting Potential

when neurotransmitters are not firing

Action potential

electrical impulses that travel down the axon.

Threshold

minimum simulation needed to trigger an action potential

What’s simulating an action potential?

neurotransmitters released by other neurons can stimulate the receiving neuron and change its electrical charge.

ALL/NONE Principal

a neuron either fires or doesn’t fire

Refractory Period

a small recovery after firing an electrical impulse

Reuptake

sending neurons re-absorbes neurotransmitters from the synapse

Excitatory neurotransmitters

increases the likelihood that the receiving neuron will fire

Inhibitory neuron

the lower likelihood that the receiving neuron will fire.

Agonist

a substance that increases or mimics a neurotransmitters’ efforts

Antagonist

a substance that reduces or blocks a neuron’s effects.

Depolarization

the inside of the neurons becomes highly positive, allowing a nerve impulse to start.

Central nervous system

brain and spinal cord, which processes information and coordinate responses

Peripheral Nervous System

all the nerves apart from the CNS

Are there divisions under CNS or PNS?

PNS! (central as usual dhandham-atha irrukum. namma oru gov mari)

What are the 2 divisions of PNS? Their purpose

Somatic(voluntary movements[raising hands])
Autonomic(involuntary movements [heart-beat, breathing])

Are there any divisions under Autonomic?

Yes! Sympathetic (prepares your body for action during stress. high heart beat, alertness, breathing)
Parasympathetic (calms the body, supports rest and digestive activities)

2 branches of Somatic?

sensory input(carries information from sensory receptors to CNS)
motor output(carries commands from CNS to skeletal movements - voluntary movements)