Psychology ch.3 vocab

Reflex

An automatic, involuntary response to a stimulus, as envisioned in Descartes’ model of action

Neuron

A specialized cell in the nervous system that accumulated and transmits information

Dendrites

The branched part of a neuron that receives impulses and conducts them toward the cell body

Cell body

The portion of the neuron containing the nucleus and metabolic machinery that keeps the cell alive

Axon

The part of a neuron that transmits impulses to glands, muscles, or other neurons

Myelin sheath

A fatty substance produces by glial cells that wraps around axons, providing insulation and speeding conduction

Glia

Cells in the nervous system that support, nourish, insulate, and regulate neurons

Afferent neurons

Nerves that carry messages inward toward the central nervous system

Efferent neurons

Nerves that carry messages outward from the central nervous system

Interneurons

Neurons that connect other neurons within the central nervous system

Action potential

A brief change in the electrical charge of a neuronal membrane; the physical basis of the neural signal

All-or-none law

The role that once an action potential is triggered, it always occurs with the same strength and speed regardless of stimulus intensity

Synapse

The small gap between two adjacent neurons where neurotransmitters carry signals

Neurotransmitters

Chemicals released by one neuron that trigger a response in another neuron; the main means of neural communication

Presynaptic neuron

Chemicals released by one neuron that trigger a response in another neuron; the main means of neural communication

Postsynaptic neuron

The neuron receiving the signal at the synapse

Synaptic vesicles

Tiny sacs in the presynaptic axon terminals containing neurotransmitters

Lock-and-key model

Theory that neurotransmitters affect postsynaptic receptors only if their shape precisely matches the receptor site

Agonists

Drugs or chemicals that enhance neurotransmitter activity

Antagonists

Drugs or chemicals that block or reduce neurotransmitter activity

Blood-brain barrier

Specialized membranes surrounding brain blood vessels that filter harmful chemicals and toxins

Endocrine system

A system of glands that release hormones directly into the bloodstream into influence organs elsewhere in the body

Hormones

Chemical messengers released into the bloodstream that regulate bodily functions such as metabolism, arousal, and growth

Brain stem

Structure at the tip if the spinal chord that includes the medulla and pons; regulates basic life functions

Cerebellum

Brain structure involved in coordination, balance, and timing of movements

Thalamus

Brain structure that acts as a relay station for sensory information

Hypothalamus

Brain structure involved in regulating motivated behaviors And maintaining homeostasis

Amygdala

Limbic system structure critical for processing emotions, especially fear

Limbic system

A set of brain structures involved in emotion, motivation, and memory

Hippocampus

Limbic system structure essential for forming more memories

Cerebral cortex

The outermost layer of the forebrain, involved in higher cognitive processes such as language, thought, and planning.

Frontal lobes

Regions at the front of the brain responsible for planning, decision-making, impulse control, and personality

Parietal lobes

Brain regions that integrate sensory information and represent spatial layout and body maps

Temporal lobes

Brain regions involved in processing sound, speech, and memory

Occipital lobes

Brain regions responsible for visual processing

Somatic nervous system

The division of the peripheral nervous system that controls skeletal muscles and conveys sensory information

Autonomic nervous system

The division of the peripheral nervous system that controls internal organs

Sympathetic branch

Subdivision of the ANS that mobilizes energy and prepares the body for action

Parasympathetic branch

Subdivision of the ANS that restores energy and brings the body back to rest

Corpus callosum

The bundle of fibers that connects the two hemispheres of the brain

Lateralization

The tendency for certain functions to be specialized to one hemisphere of the brain

Plasticity

The brain’s capacity to change its structure and function in response to experience, damage, or learning