AP Psychology Unit 1: Biological Bases Vocabulary 3

Biopsychosocial approach

Behavior explained through biological, psychological, and social-cultural influences

Nervous system

Body's electrochemical communication network

Nerves

Bundles of axons connecting CNS to muscles, glands, and sensory organs

Neural transmission

Communication between neurons

Multiple sclerosis (MS)

Disease involving deterioration of the myelin sheath

Acetylcholine (ACh)

Enables muscle action, learning, and memory

Dopamine pathways

Neural pathways involved in reward, motivation, and movement

Blood-brain barrier

Protects the brain by restricting substances entering from blood

Neural plasticity

Nervous system's ability to change in response to experience or damage

Phrenology

Outdated idea that skull shape reveals mental abilities/traits

Localization

Specific brain areas have specialized functions

Brain lateralization

Certain functions are more strongly associated with one hemisphere

Split-brain research

Studies people whose corpus callosum has been severed

Roger Sperry

Major split-brain researcher

Michael Gazzaniga

Major researcher of hemispheric specialization

Left-hemisphere interpreter

Tendency of the left hemisphere to construct explanations from available information

Reward center

Brain areas involved in pleasure and reinforcement

Homeostasis

Maintaining a stable internal state

Neuroplasticity

Brain's ability to reorganize after experience or injury

Biological rhythms

Periodic physiological changes

Suprachiasmatic nucleus (SCN)

Hypothalamic structure controlling circadian rhythms

Cell body (soma)

Contains the neuron's nucleus

Axon terminals

Release neurotransmitters

Terminal buttons

Endings of an axon that release neurotransmitters

Synaptic vesicles

Sacs containing neurotransmitters

Synaptic gap/cleft

Tiny space between neurons

Receptor sites

Locations where neurotransmitters bind

Excitatory neurotransmitter

Increases likelihood neuron will fire

Inhibitory neurotransmitter

Decreases likelihood neuron will fire

Neural impulse

Electrical signal traveling through neuron

Spinal cord

Carries information between brain and body

Neural networks

Interconnected groups of neurons

Sensory cortex

Processes sensory information

Left hemisphere

Often dominant for language

Right hemisphere

Often stronger in spatial/perceptual processing

Hemispheric specialization

Different hemispheres specialize in certain functions

Psychoactive drug

Substance that alters perception, mood, or consciousness

Tolerance

Needing more of a drug to produce the same effect

Withdrawal

Unpleasant effects after stopping a drug

Addiction

Compulsive substance use despite harmful consequences

Depressants

Slow nervous-system activity

Stimulants

Increase nervous-system activity

Hallucinogens

Distort perceptions

Opiates/Opioids

Pain-relieving drugs that affect endorphin systems

Nature-nurture issue

Relative influence of genes vs. environment

Genotype

Person's genetic makeup

Phenotype

Observable characteristics

Molecular genetics

Studies specific genes and their effects

Twin studies

Compare identical/fraternal twins to study heredity

Adoption studies

Compare adoptees with biological/adoptive families

Evolution

Change in inherited characteristics over generations

Adaptation

Inherited characteristic that improves survival/reproduction

Forebrain

Higher-level brain region containing structures such as cortex and limbic system

Midbrain

Involved in movement and sensory processing

Hindbrain

Includes medulla, pons and cerebellum

Gray matter

Primarily neuron cell bodies

White matter

Primarily myelinated axons

Localization of function

Particular brain regions perform particular functions

Pineal gland

Releases melatonin

Melatonin

Hormone involved in sleep-wake cycles

Ovaries

Produce estrogen and progesterone

Testes

Primarily produce testosterone

Estrogen

Sex hormone involved in reproductive development

Testosterone

Sex hormone involved in reproductive development

Biological psychology

Studies links between biology and behavior

Neuron

Nerve cell; basic unit of nervous system

Dendrites

Receive incoming signals

Axon

Carries signals away from cell body

Myelin sheath

Fatty covering that speeds neural impulses

Glial cells

Support, nourish, and protect neurons

Action potential

Electrical impulse traveling down an axon

Threshold

Minimum stimulation needed to fire

All-or-none response

Neuron either fires completely or doesn't

Refractory period

Brief period when neuron cannot fire again

Resting potential

Neuron's electrically charged resting state

Depolarization

Change in electrical charge that produces firing

Synapse

Gap between communicating neurons

Neurotransmitters

Chemical messengers between neurons

Reuptake

Sending neuron reabsorbs neurotransmitters

Agonist

Increases/mimics neurotransmitter activity

Antagonist

Blocks/decreases neurotransmitter activity

Dopamine

Movement, learning, attention, reward

Serotonin

Mood, hunger, sleep, arousal

Norepinephrine

Alertness and arousal

GABA

Major inhibitory neurotransmitter

Glutamate

Major excitatory neurotransmitter; memory

Endorphins

Natural pain control and pleasure

Substance P

Involved in pain signals

Central nervous system (CNS)

Brain + spinal cord

Peripheral nervous system (PNS)

Nerves outside brain/spinal cord

Sensory (afferent) neurons

Carry information to CNS

Motor (efferent) neurons

Carry commands from CNS

Interneurons

Process information within CNS

Somatic nervous system

Controls voluntary skeletal muscles

Autonomic nervous system

Controls glands/internal organs

Sympathetic nervous system

Arouses body; fight-or-flight

Parasympathetic nervous system

Calms body; rest-and-digest

Reflex

Automatic response to stimulus

Reflex arc

Neural pathway responsible for a reflex

Brainstem

Oldest brain region; basic survival functions