Neuroscience: Key Terms and Concepts in Nervous System

Motor output

Activates muscles or glands (effectors)

Neuroglia (glial cells)

Support, protect, and insulate neurons

Encephalo-

Prefix meaning brain

Myel-

Prefix meaning myelin

-pathy

Suffix meaning disease

Neurons

Transmit electrical signals

Sensory (afferent) neurons

Carry impulses to the CNS

Motor (efferent) neurons

Carry impulses from the CNS

Interneurons

Connect neurons within the CNS

Dendrites

Receive incoming signals

Myelin sheath

Insulating layer that speeds transmission

Node of Ranvier

Gaps in myelin; allow saltatory conduction

Reflex Arc

A rapid, involuntary response

Action Potential

A rapid electrical impulse that travels along a neuron's axon

All-or-None Rule

If threshold is reached → full action potential; if not → no action potential

Synaptic Transmission

Action potential reaches axon terminal; neurotransmitters released into synaptic cleft

Acetylcholine (ACh)

Neurotransmitter involved in muscle contraction and memory

Dopamine

Neurotransmitter involved in reward and movement

Serotonin

Neurotransmitter involved in mood and sleep

Norepinephrine

Neurotransmitter involved in alertness and stress

GABA

Major inhibitory neurotransmitter

Sensory input

Detects stimuli from internal and external environments

Integration

Processes and interprets sensory information

Central Nervous System (CNS)

Brain and spinal cord; integration and control center

Peripheral Nervous System (PNS)

All nerves outside the CNS; connects CNS to body

Neuro-

Prefix meaning nerve

Cerebro-

Prefix meaning brain

-itis

Suffix meaning inflammation

Cell body (soma)

Contains nucleus; metabolic center

Axon

Conducts impulses away from cell body

Axon terminal

Releases neurotransmitters

Synaptic bulb

End of axon terminal containing vesicles

Still learning (21)

You've started learning these terms. Keep it up!