unit 3 psych

Behavior genetics

Study of how heredity and environment influence behavior.

Twin studies

Compare identical and fraternal twins to examine genetic and environmental influences.

Adoption studies

Compare adopted people with biological and adoptive relatives to study nature and nurture.

Epigenetics

Environmental factors can influence gene expression without changing DNA.

Evolutionary psychology

Explains behavior through natural selection and evolution.

CNS (central nervous system)

Brain and spinal cord.

PNS (peripheral nervous system)

All nerves outside the brain and spinal cord.

Somatic nervous system

Controls voluntary movement and carries sensory information.

Autonomic nervous system

Controls involuntary functions.

Sympathetic nervous system

Activates the body for arousal/fight-or-flight.

Parasympathetic nervous system

Calms the body and returns it toward normal after arousal.

Dendrites

Receive signals from other neurons.

Soma (cell body)

Contains the nucleus and maintains the neuron.

Axon

Carries neural signals away from the cell body.

Myelin sheath

Fatty covering that speeds neural communication.

Sensory (afferent) neuron

Carries information toward the CNS.

Motor (efferent) neuron

Carries commands from the CNS to muscles and glands.

Interneuron

Connects and processes information within the CNS.

Resting potential

Neuron's resting electrical state.

Threshold

Minimum stimulation needed to trigger an action potential.

Action potential

Electrical signal that travels down the axon.

All-or-none response

Neuron either fires completely or does not fire.

Refractory period

Brief period after firing when the neuron resets.

Synapse

Space/junction between neurons.

Reuptake

Neurotransmitters are taken back into the sending neuron.

Acetylcholine (ACh)

Neurotransmitter involved in muscle action, learning, and memory.

Dopamine

Neurotransmitter involved in movement, motivation, and reward.

Serotonin

Neurotransmitter involved in mood and other functions.

Norepinephrine

Neurotransmitter involved in arousal and alertness.

GABA

Inhibitory neurotransmitter that reduces neural activity.

Glutamate

Excitatory neurotransmitter important in learning and memory.

Endorphins

Neurotransmitters involved in reducing pain.

Substance P

Neurotransmitter involved in transmitting pain signals.

Agonist

Mimics or enhances a neurotransmitter's effects.

Antagonist

Blocks or reduces a neurotransmitter's effects.

Stimulants

Increase nervous-system activity; examples include caffeine and cocaine.

Depressants

Decrease nervous-system activity; alcohol is an example.

Opioids

Drugs that reduce pain; heroin is an example.

Hallucinogens

Drugs that alter perception; marijuana is listed in the guide.

Tolerance

Need for more of a substance to produce the same effect.

Withdrawal

Symptoms that occur when substance use is reduced or stopped.

Endocrine system

Uses hormones released into the bloodstream to communicate.

Ghrelin

Hormone associated with hunger.

Leptin

Hormone associated with satiety/fullness.

Melatonin

Hormone involved in sleep and circadian rhythms.

Adrenaline

Hormone associated with arousal and fight-or-flight.

Oxytocin

Hormone associated with bonding and social functions.

Homeostasis

Maintaining a stable internal environment.

Feedback loop

A process where the effects of a system regulate further activity.

Hypothalamus

Helps regulate homeostasis and endocrine activity.

Pituitary gland

Endocrine gland that releases hormones and helps regulate endocrine functions.

Medulla

Brainstem structure involved in vital functions such as breathing and heart rate.

Pons

Brainstem structure involved in sleep and arousal.

Reticular formation

Brain network involved in arousal and alertness.

Cerebellum

Important for balance, coordination, and movement.

Thalamus

Major relay station for sensory information.

Amygdala

Involved in emotion, especially fear.

Hippocampus

Involved in forming and processing memories.

Nucleus accumbens

Associated with reward.

Frontal lobe

Involved in planning, decision-making, movement, and higher-level functions.

Parietal lobe

Processes body sensations and spatial information.

Occipital lobe

Primarily involved in vision.

Temporal lobe

Involved in hearing, language processing, and memory.

Broca's area

Associated with speech production.

Wernicke's area

Associated with language comprehension.

Corpus callosum

Connects the left and right brain hemispheres.

Lateralization

Specialization of functions between the brain's hemispheres.

Contralateral organization

Each hemisphere generally controls or receives information from the opposite side of the body.

Neuroplasticity

Brain's ability to change and reorganize.

EEG

Records electrical activity in the brain.

fMRI

Shows brain activity through changes in blood flow.

MRI

Produces detailed images of brain structure.

PET

Shows patterns of metabolic activity in the brain.

Circadian rhythm

Approximately 24-hour biological rhythm regulating processes such as sleep.

NREM 1

Lightest stage of sleep; transition into sleep.

NREM 2

Stage characterized by sleep spindles and K-complexes.

NREM 3

Deepest NREM stage.

REM sleep

Stage with rapid eye movements and vivid dreaming.

Activation-synthesis theory

Dreams result from the brain making sense of random neural activity.

Consolidation theory

Dreaming is related to processing and consolidating information and memories.

Insomnia

Difficulty falling asleep or staying asleep.

Narcolepsy

Sudden, uncontrollable episodes of sleep.

Sleep apnea

Repeated interruptions of breathing during sleep.