unit 2

Neuron

Basic cell of the nervous system

Dendrites

Receive incoming signal from the soma

Cell body

Includes the nucleus

Axon

Action potential travels down this

Myelin Sheath

Speeds up signal down the axon

Terminals

Release neurotransmitters to send signals to the next neuron

Synapse

Gap between neurons where neurotransmitters are released

Action Potential

Movement of ions sending an electrical charge down the axon

All or None Law

Stimulus must trigger the action potential past its threshold

Refractory Period

Neuron must rest and reset before sending another action potential

Sensory Neurons

Receive signals

Motor Neurons

Send signals

Efferent Neurons

Signal exits

Central Nervous System

Brain and spinal cord

Peripheral Nervous System

Rest of the nervous system

Somatic Nervous System

Voluntary movement

Autonomic Nervous System

Involuntary functions

Neurotransmitters

Chemicals released in the synaptic gap

GABA

Major inhibitory neurotransmitter

Glutamate

Major excitatory neurotransmitter

Dopamine

Related to reward and movement

Serotonin

Affects moods and emotions

Acetylcholine (ACh)

Involved in memory

Epinephrine & Norepinephrine

Related to sympathetic nervous system arousal

Endorphins

Control pain and happiness

Oxytocin

Related to love and bonding

Agonist

Drug that mimics a neurotransmitter

Antagonist

Drug that blocks a neurotransmitter

Reuptake

Process where unused neurotransmitters are taken back into the sending neuron

SSRIs

Selective serotonin reuptake inhibitors used in depression treatment