(FINALE) Biopsychology I

Neuron

Basic nerve cell that transmits information.

Dendrites

Branch-like structures that receive messages from other neurons.

Cell Body (Soma)

Contains the nucleus and integrates incoming signals.

Axon

Long fiber that carries signals away from the cell body.

Myelin Sheath

Fatty coating around axons that speeds up signal transmission.

Nodes of Ranvier

Gaps in the myelin sheath that help electrical signals jump faster.

Axon Terminals

Ends of the axon where neurotransmitters are released.

Synapse

Gap between neurons where neurotransmitters travel.

Neurotransmitters

Chemicals that transmit signals across synapses.

Receptors

Proteins on dendrites that receive neurotransmitters.

Action Potential

Electrical impulse that travels down an axon.

Resting Potential

Neuron’s baseline electrical charge.

Threshold

Level of stimulation needed to trigger an action potential.

All-or-None Law

Neurons fire completely or not at all.

Excitatory vs Inhibitory Signals

Excitatory signals increase firing likelihood; inhibitory signals decrease it.

Central Nervous System (CNS)

Brain and spinal cord.

Peripheral Nervous System (PNS)

Nerves connecting the CNS to the rest of the body.

Somatic Nervous System

Controls voluntary movement.

Autonomic Nervous System

Controls involuntary functions like heartbeat and digestion.

Sympathetic Nervous System

Activates “fight or flight” responses.

Parasympathetic Nervous System

Activates “rest and digest” functions.