psyc chap 3 fiest round

Dendrites

Branch-like extensions of a neuron that receive incoming signals from other neurons.

Cell body (soma)

The central part of a neuron that contains the nucleus and maintains life-sustaining cellular functions.

Axon

A long, slender nerve fiber that carries electrical impulses away from the cell body.

Myelin sheath

A fatty layer surrounding the axon that insulates it and increases the speed of electrical signals.

Axon terminals

Specialized endings of an axon that release chemical messengers to communicate with adjacent cells.

Synapse

The junction where a neuron communicates with a target cell.

Synaptic cleft

The microscopic gap between neurons across which chemical messengers diffuse.

Neurotransmitters

Endogenous chemical messengers used by neurons to transmit signals across synapses.

Action potential

A rapid, brief electrical impulse that propagates along an axon.

All-or-none principle

The rule stating that an electrical impulse triggers completely once threshold is met, or fails to trigger entirely.

Threshold

The minimum level of stimulation required to elicit an action potential.

Dopamine

A neurotransmitter strongly associated with reward pathways, motivation, and motor control.

Serotonin

A neurotransmitter primarily involved in regulating mood, sleep, appetite, and emotional state.

Acetylcholine (ACh)

A neurotransmitter that plays a key role in muscle contraction, learning, and memory formation.

GABA

The primary inhibitory neurotransmitter in the central nervous system that reduces neuronal excitability.

Glutamate

The primary excitatory neurotransmitter in the central nervous system, central to synaptic plasticity and learning.

Endorphins

Naturally produced peptide chemicals that inhibit the transmission of pain signals and promote feelings of well-being.

Central nervous system (CNS)

The primary control center of the body comprising the brain and spinal cord.

Peripheral nervous system (PNS)

The network of nerves situated outside the brain and spinal cord connecting the body to the central system.

Somatic nervous system

A division of the peripheral nervous system responsible for voluntary control of skeletal muscles.

Autonomic nervous system

A division of the peripheral nervous system regulating involuntary physiological functions such as heart rate and digestion.

Sympathetic nervous system

A subdivision of the autonomic nervous system that mobilizes the body during fight-or-flight emergencies.

Parasympathetic nervous system

A subdivision of the autonomic nervous system that conserves energy and facilitates rest-and-digest operations.

Frontal lobe

The cerebral region responsible for executive functions, planning, reasoning, and voluntary motor movement.

Parietal lobe

The cerebral region that processes somatosensory information, including touch, temperature, and spatial awareness.

Temporal lobe

The cerebral region dedicated to auditory processing, speech interpretation, and memory association.

Occipital lobe

The cerebral region located at the back of the brain primarily responsible for visual processing.

Cerebellum

The hindbrain structure responsible for fine motor coordination, posture, and motor learning.

Hippocampus

A limbic system structure vital for consolidating short-term memory into long-term memory.

Amygdala

A limbic system component central to emotional regulation, particularly fear conditioning and threat appraisal.

Thalamus

The subcortical sensory relay hub that directs sensory input to the appropriate cerebral cortical regions.

Hypothalamus

The subcortical structure responsible for maintaining homeostasis by governing hunger, thirst, temperature, and endocrine secretion.