AP Psychology Unit 1 Biological Bases of Behavior Vocabulary

Nature

Biological and genetic influences on behavior; traits inherited from parents.

Evolutionary Perspective

Explains behavior through adaptation and survival shaped by natural selection.

Natural Selection

Process where traits that improve survival or reproduction become more common over generations.

Behavior Genetics

Studies how genes and environment interact to shape behavior, often using twin and adoption studies.

Mutations

Random genetic changes that can be inherited and may be harmful, neutral, or beneficial.

Environment

All external influences on development, including family, culture, and experiences.

Heredity

Genetic transmission of traits from parents to offspring, forming the biological blueprint.

Genes

Segments of DNA that code for traits and influence physical and behavioral characteristics.

Genome

Complete set of genetic material in an organism containing all biological instructions.

Nurture

Environmental influences on development such as upbringing, culture, and life experiences.

Eugenics

Discredited movement aimed at “improving” human genetics, historically linked to harmful practices.

Identical (monozygotic) twins

Twins from one fertilized egg who share identical genetic material.

Fraternal (dizygotic) twins

Twins from two separate eggs who are genetically similar like siblings.

Interaction

Combined influence of genes and environment on behavior, with both constantly affecting each other.

Epigenetics

Study of how environment affects gene expression without changing DNA.

Nervous System

Body’s communication network made of neurons that controls thoughts, movement, and functions.

Central Nervous System

Brain and spinal cord that process information and direct responses.

Nerves

Bundles of axons that carry messages between the CNS and the rest of the body.

Reflex

Automatic, rapid response to a stimulus that protects the body without conscious thought.

Autonomic Nervous System

Controls involuntary functions like heartbeat, digestion, and breathing.

Sympathetic Nervous System

Activates the body for action (“fight or flight”) by increasing energy and alertness.

Peripheral Nervous System

All nerves outside the CNS that connect it to muscles, organs, and senses.

Somatic Nervous System

Controls voluntary muscle movements and conscious actions.

Parasympathetic Nervous System

Calms the body (“rest and digest”) and conserves energy.

Neurons

Nerve cells that send and receive information, forming the basis of the nervous system.

Cell Body

Neuron’s main part containing the nucleus and maintaining cell health.

Dendrites

Branchlike structures that receive signals from other neurons and bring them to the cell body.

Axon

Long fiber that sends electrical signals to other neurons or muscles.

Myelin

Fatty coating that speeds neural transmission; damage slows or blocks signals.

Synapse

Gap between neurons where neurotransmitters carry messages.

Glial Cells

Support cells that nourish, protect, and assist neurons.

Reflex Arc

Pathway controlling reflexes that allows quick responses without brain involvement.

Sensory Neurons

Carry information from sensory receptors to the CNS.

Motor Neurons

Carry instructions from the CNS to muscles for movement.

Interneurons

Connect sensory and motor neurons within the CNS and coordinate responses.

Action Potential

Electrical impulse traveling down the axon that sends neural messages.

All-Or-Nothing Principle

Neurons fire completely or not at all; impulse strength does not vary.

Depolarization

Positive ions enter the neuron, triggering the start of an action potential.

Reuptake

Process where neurotransmitters are reabsorbed by the sending neuron.

Multiple Sclerosis

Condition where myelin breaks down, disrupting neural communication.

Neurotransmitters

Chemical messengers between neurons that influence mood, movement, and thinking.

Excitatory Neurotransmitters

Increase the likelihood that a neuron will fire.

Dopamine

Influences movement, reward, and motivation.

Norepinephrine

Helps control alertness and arousal.

GABA

Main inhibitory neurotransmitter that calms neural activity.

Substance P

Neurotransmitter involved in pain perception.

Hormones

Chemical messengers released into the bloodstream that regulate body processes.

Leptin

Hormone that reduces hunger and helps regulate body weight.

Melatonin

Hormone that regulates sleep cycles and increases in darkness.

Refractory Period

Time after firing when a neuron cannot fire again.

Resting Potential

Neuron’s stable, inactive state before firing.

Threshold

Minimum stimulation needed to trigger an action potential.

Myasthenia Gravis

Disorder causing muscle weakness due to impaired nerve-muscle communication.

Inhibitory Neurotransmitters

Reduce the likelihood of neuron firing and slow neural activity.

Serotonin

Affects mood, sleep, and appetite.

Glutamate

Main excitatory neurotransmitter involved in learning and memory.

Endorphins

Natural painkillers that produce pleasure and reduce discomfort.

Acetylcholine

Involved in movement and memory.

Endocrine System

Glands that release hormones into the bloodstream.

Adrenaline

Hormone that increases arousal and energy.

Ghrelin

Hormone that increases hunger.

Oxytocin

Hormone linked to bonding, trust, and social behavior.

Psychoactive Drugs

Substances that alter mood, perception, or behavior.

Substance Use Disorder

Problematic drug use that affects daily life.

Antagonist

Drug that blocks neurotransmitter action.

Stimulants

Drugs that increase neural activity and energy.

Caffeine

Mild stimulant that increases alertness.

Cocaine

Stimulant that increases dopamine levels.

Methamphetamines

Powerful stimulants affecting the nervous system.

Ecstasy

Stimulant/hallucinogen that increases serotonin.

Opioids

Drugs that reduce pain and produce euphoria.

Heroin

Opioid that produces intense euphoria and carries high risk.

Addiction

Compulsive drug use despite harm.

Agonist

Drug that mimics neurotransmitter action.

Reuptake Inhibitor

Drug that prevents neurotransmitter reabsorption.

Depressants

Drugs that slow neural activity.

Barbiturates

Strong depressants that reduce anxiety.

Alcohol

Depressant that impairs judgment and coordination.

Hallucinogens

Drugs that distort perception and cause sensory experiences.

Near-Death Experience

Altered state reported after close calls with death.

Marijuana

Drug producing relaxation and altered perception.

LSD

Hallucinogen causing sensory distortions.

Tolerance

Needing more of a substance to achieve the same effect.

Withdrawal

Symptoms after stopping a substance the body has adapted to.

Nicotine

Addictive stimulant found in tobacco.

Biological Psychology

Study of how biological processes influence behavior.

Biopsychosocial Approach

Explains behavior through biological, psychological, and social factors.

Levels of Analysis

Different perspectives used to explain behavior.

Brain Plasticity

Brain’s ability to change and reorganize.

EEG

Measures electrical activity in the brain.

MEG

Measures magnetic fields from neural activity.

MRI

Produces detailed images of brain structures.

CT

Uses X-rays to create brain images.

PET

Shows brain activity using radioactive glucose.

fMRI

Shows brain activity by measuring blood flow.

Lesions

Tissue destruction used to study brain function.

Brain Stem

Controls basic survival functions.

Hindbrain

Controls movement and vital functions.

Midbrain

Coordinates movement and sensory processing.

Forebrain

Responsible for complex thinking and emotion.