AP Psychology 2025 Unit 1 AP review

Heredity

The passing on of physical or mental characteristics genetically from one generation to another

Nature

What we think of as pre-wiring and is influenced by genetic inheritance and other biological factors

Nurture

Generally taken as the influence of external factors after conception, e.g., the product of exposure, life experiences and learning on an individual

Genetic Predisposition

An increased chance or likelihood of developing a particular disease based on the presence of one or more genetic variants and/or a family history suggestive of an increased risk of the disease

Evolutionary Psychology

The branch of psychology that studies the mental adaptations of humans to a changing environment

Natural Selection

Certain behaviors or traits improve survival chances and get passed on (e.g. phobias, anxiety, etc.)

Identical Twins

Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms

Fraternal Twins

Twins who develop from separate fertilized eggs; genetically no closer than siblings but share a fetal environment

Eugenics

The study of how to arrange reproduction within a human population to increase the occurrence of heritable characteristics regarded as desirable

Epigenetics

The study of heritable changes in gene expression that occur without a DNA change

Twin Studies

Studies conducted on identical or fraternal twins to reveal the importance of environmental and genetic influences

Adoption Studies

Compare adopted children to biological and adoptive parents to assess genetic and environmental influences

Family Studies

Look at genetics and mental disorders across family lines

Behavioral Genetics

Focus on discovering how genes and environment interact and lead to specific behaviors

Genes

Segments of DNA that contain instructions to make proteins – building blocks of life

Genome

The entire set of genetic material in an organism

Mutations

A permanent change in an organism’s genetic material

Nervous System

The body’s electrochemical communications network

Central Nervous System

The brain & spinal cord, which distribute & process messages

Peripheral Nervous System

A branch of the human nervous system that controls voluntary movements

Somatic Nervous System

The part of the peripheral nervous system that controls voluntary movements

Autonomic Nervous System

A part of the peripheral nervous system that regulates bodily processes such as breathing, heart rate, and digestion

Sympathetic Nervous System

Branch of the autonomic nervous system that excites body for action (FIGHT OR FLIGHT)

Parasympathetic Nervous System

Branch of the autonomic nervous system that restores the body’s energy sources (REST AND DIGEST)

Nerves

Bundles of fibers that transmit impulses between different areas within our bodies

Reflex

An involuntary response to a stimulus that happens without conscious thought

Neurons

Individual nerve cells that make up our entire nervous system

Glial Cells

Provide nutrition and protection for the neurons

Sensory Neurons

Neurons that take information from the senses to the brain

Motor Neurons

Neurons that take information from the brain to the rest of the body

Interneurons

Neurons in the brain or spinal cord that relay messages

Spinal Reflex

An immediate response to external stimuli directed at the level of the spinal cord

Mirror Neurons

Neurons that play a role in action understanding and imitation

Action Potential

An impulse or brief electric charge that travels down the axon

Threshold

The level of stimulation needed to trigger a neural impulse

All or None Response

A neuron either fires an impulse or it does not

Resting Potential

When a neuron is not firing; positive outside, negative inside

Depolarization

Positive ions enter the axon and cause a chain reaction of firing

Refractory Period

Resting phase when neuron resets and can’t fire again immediately

Reuptake

Reabsorption of neurotransmitters by the sending neuron

Excitatory Neurotransmitters

Stimulate the brain

Inhibitory Neurotransmitters

Calm the brain and create balance

Multiple Sclerosis

Loss of muscle control due to myelin sheath deterioration

Myasthenia Gravis

Autoimmune disorder causing muscle weakness due to blocked acetylcholine

Neurotransmitters

Chemical messengers that cross synaptic gaps between neurons

Hormone

A chemical messenger produced in the body that controls and regulates activity of certain cells or organs

Acetylcholine (ACh)

Enables muscle action, learning, and memory

Dopamine

Influences movement, learning, attention, and emotion

Serotonin

Affects mood, hunger, sleep, and arousal

Norepinephrine

Helps control alertness and arousal

GABA

A major inhibitory neurotransmitter

Glutamate

A major excitatory neurotransmitter; involved in memory

Endorphins

Neurotransmitters that influence pain or pleasure

Substance P

Involved in pain perception and immune response

Psychoactive Drugs

Chemical substances that alter perceptions, mood, or behavior

Addiction

Craving a drug or chemical substance despite its adverse effects

Tolerance

Needing more of a drug to experience the same effect

Withdrawal

Symptoms experienced when discontinuing a drug

Substance Use Disorder

Continued drug use despite significant life disruption or physical risk

Depressants

Lower neural activity and slow body functioning

Barbiturates

Drugs that reduce neurotransmission and temporarily lessen pain and anxiety

Stimulants

Drugs that speed up the body’s functions

Hallucinogens

Drugs that distort perceptions of reality

Agonists

Chemicals that activate neurotransmitter receptors

Antagonists

Chemicals that block neurotransmitters

Reuptake Inhibitors

Drugs that prevent reabsorption of neurotransmitters

Adrenaline

Hormone that activates sympathetic nervous system (fight or flight)

Melatonin

Hormone that regulates sleep and wake cycles

Ghrelin

Hormone that increases hunger

Leptin

Hormone that decreases hunger

Oxytocin

Hormone involved in bonding and reproduction

Brainstem

Oldest part of brain; controls survival functions

Medulla

Controls heartbeat, breathing, and reflexes

Reticular Activating System

Regulates arousal, consciousness, and voluntary movement

Cerebellum

Coordinates movement, balance, and memory

Thalamus

Brain’s sensory control center

Limbic System

Neural system related to emotions and drives

Hippocampus

Vital to memory formation

Amygdala

Regulates fear and aggression

Hypothalamus

Maintains homeostasis and regulates hormones

Pituitary Gland

Master endocrine gland

Left Hemisphere

Controls language, logic, and right side of body

Right Hemisphere

Controls perception, creativity, and left side of body

Corpus Callosum

Connects left and right hemispheres

Cerebral Cortex

Outer brain layer responsible for higher functions

Frontal Lobe

Involved in speaking, movement, judgment

Prefrontal Cortex

Handles attention, planning, and working memory

Broca’s Area

Controls speech production

Parietal Lobe

Receives sensory input for touch/body position

Occipital Lobe

Processes visual information

Temporal Lobe

Processes auditory information

Wernicke’s Area

Comprehends language

Motor Cortex

Controls voluntary movement

Sensory Cortex

Registers and processes touch sensations

Association Areas

Integrate information for complex tasks

Contralateral Hemispheric Organization

Opposite side of brain controls opposite side of body

Split Brain

Condition where corpus callosum is severed

Neuroplasticity

Reorganization of neural pathways by experience

Brain Lesion

Destroyed brain tissue due to injury or disease

EEG

Measures brain wave activity through scalp electrodes