AP Psych Cards (1.1-1.4)

Psychology

The scientific study of behavior and mental processes.

Heredity (nature)

Genetic or predisposed characteristics that influence physical, behavioral, and mental traits.

Environmental factors (nurture)

External experiences that shape a person, such as family interactions or education.

Genetic predisposition

An inherited tendency that influences which traits can develop, depending on environmental conditions.

Epigenetics

Behavior and environment cause changes in how genes are read/expressed without changing the DNA sequence; reversible.

Evolutionary perspective

Explores how natural selection shaped behavior and mental processes to increase survival and reproduction.

Natural selection

Genetically influenced traits that aid survival and reproduction are more likely to be passed to future generations.

Eugenics

The discriminatory misuse of evolutionary principles to decide who is "fit" to reproduce; led to forced sterilization and justifying social hierarchies.

Twin studies

Research comparing identical and fraternal twins to separate the effects of genes from environment.

Identical (monozygotic) twins

Twins from one fertilized egg who share the same genes; more behaviorally similar than fraternal twins.

Fraternal (dizygotic) twins

Twins from two separate eggs who share about 50% of genes, like any siblings.

Family studies

Research comparing trait similarity among biological relatives to estimate genetic influence.

Adoption studies

Research comparing adopted children to their genetic relatives vs. their environmental (adoptive) relatives.

Nervous system

Brain + spinal cord + nerves; coordinates action and sensory information by transmitting signals through the body.

Central nervous system (CNS)

The brain and spinal cord; the body's integration and command center.

Nerves

Bundled axons that carry signals between the CNS and the rest of the body.

Peripheral nervous system (PNS)

All nerves outside the brain and spinal cord; relays messages between the CNS and the body.

Autonomic nervous system

PNS division governing involuntary processes (glands, organs, heart, digestion); includes sympathetic and parasympathetic.

Somatic nervous system

PNS division governing voluntary movement of skeletal muscles.

Sympathetic nervous system

Arousing division of the autonomic system; triggers fight-or-flight (heart rate up, pupils dilate, digestion inhibited).

Parasympathetic nervous system

Calming division of the autonomic system; returns the body to rest (heart rate down, digestion stimulated).

Neurons

Specialized cells of the nervous system that transmit information throughout the body.

Dendrites

Branching extensions that receive messages from other neurons.

Axon

Extension that passes messages away from the cell body to other neurons, muscles, or glands.

Myelin sheath

Fatty covering over some axons that insulates them and speeds up neural impulses.

Synapse

The gap between two neurons where neurotransmitters are released to the next neuron.

Glial cells

Cells that provide structure, insulation, communication, and waste transport; nourish and maintain neurons.

Reflex

An automatic, involuntary response to a stimulus.

Reflex arc

Spinal cord pathway of sensory neuron → interneuron → motor neuron that produces a response without waiting on the brain.

Sensory neurons

Carry messages from the environment/body toward the CNS (afferent).

Motor neurons

Carry messages for movement away from the CNS to muscles and glands (efferent).

Interneurons

Neurons within the CNS that process information between sensory and motor neurons.

Neural transmission

The orderly process by which a neuron receives, fires, and passes along a signal.

Resting potential

Polarized state of a neuron at rest: membrane impermeable ("doors closed"), inside negatively charged.

Threshold

The level of stimulation required to trigger a neural impulse.

Depolarization

Sodium channels open and positive ions rush in, making the inside of the neuron less negative.

Action potential

The neural impulse; an electrical charge that travels down the axon when threshold is reached.

All-or-nothing principle

A neuron either fires at full strength or does not fire at all; intensity does not vary.

Refractory period

Brief recovery phase after firing when the membrane repolarizes and the neuron cannot fire again.

Reuptake

Excess neurotransmitters are reabsorbed back into the sending neuron's terminal buttons.

Multiple sclerosis

Disorder in which the immune system attacks the myelin sheath, slowing or blocking neural transmission.

Myasthenia gravis

Autoimmune disorder disrupting ACh communication between nerves and muscles; causes weakness in voluntary muscles.

Neurotransmitters

Chemical messengers released by a neuron across a synapse to affect another neuron, gland, or muscle cell.

Excitatory neurotransmitters

Make an action potential MORE likely by depolarizing the receiving membrane.

Inhibitory neurotransmitters

Make an action potential LESS likely by making the receiving membrane more negative.

Dopamine

Movement, posture, attention, pleasure, and reward. Too much: schizophrenia. Too little: Parkinson's disease.

Serotonin

Mood, sleep and arousal, appetite. Too little: depression, anxiety disorders, impulsivity. SSRIs block its reuptake.

Norepinephrine

Alertness and arousal, energy and glucose metabolism; involved in the fight-or-flight response. Too little: depression.

Glutamate

Main excitatory neurotransmitter; involved in memory formation. Too much: migraines, seizures, nerve cell death (Huntington's).

GABA

Main inhibitory neurotransmitter; calming, inhibits anxiety. Too little: epilepsy, anxiety, tremors, insomnia. Alcohol stimulates it.

Endorphins

Block the perception of pain and increase feelings of wellbeing; natural opioids resembling morphine.

Substance P

Neurotransmitter involved in pain perception, plus stress, anxiety, and nausea. Linked to fibromyalgia.

Acetylcholine (ACh)

Muscle action, learning, memory, and sleep. Too little: Alzheimer's, paralysis.

Endocrine system

System of glands that secrete hormones into the bloodstream; slower but longer-lasting than neural signals.

Pituitary gland

The "master gland"; directed by the brain, it signals other glands to release hormones.

Hormones

Chemical messengers made by glands and carried in the bloodstream; act on many organs at once.

Adrenaline (epinephrine)

Hormone released during fight-or-flight; increases heart rate, energy, and alertness.

Leptin

Hormone released by fat cells that signals fullness and helps maintain long-term normal weight.

Ghrelin

Hormone produced by the stomach that signals hunger and increases the drive to eat.

Melatonin

Sleep hormone; production increases in darkness and decreases in light, regulating the sleep/wake cycle.

Oxytocin

"Love hormone"; social bonding, trust, childbirth, and the period after childbirth.

Psychoactive drugs

Substances that alter perception, consciousness, cognition, or mood by acting on neurotransmitter function.

Agonist

A drug that mimics a neurotransmitter and binds to receptors to activate them, encouraging neural firing.

Antagonist

A drug that occupies receptors without activating them, blocking the neurotransmitter and discouraging neural firing.

Reuptake inhibitor

A drug that blocks reabsorption of a neurotransmitter, leaving more of it active in the synapse.

Stimulants

Drugs that increase neural activity and speed up body functions.

Caffeine

Stimulant that increases alertness; can cause anxiety, restlessness, and insomnia.

Cocaine

Stimulant that blocks reuptake of dopamine, norepinephrine, and serotonin, producing euphoria followed by a crash.

Depressants

Drugs that reduce neural activity and slow body functions.

Alcohol

Depressant causing disinhibition and relaxation; can lead to slowed processing, memory disruption, and organ damage.

Hallucinogens

Psychedelic drugs that distort perception and evoke sensory images without sensory input.

Marijuana

Hallucinogen producing enhanced sensation, pain relief, and distorted time; can impair learning and memory.

Opioids

Drugs that depress neural functioning and relieve pain; suppress the brain's natural endorphin production.

Heroin

Opioid producing a rush of euphoria and pain relief; leads to depressed physiology and severe withdrawal.

Tolerance

The body adapts to a drug, so larger doses are needed for the same effect.

Addiction

Chronic, relapsing compulsive drug seeking and use despite adverse consequences.

Withdrawal

Physical and mental symptoms that occur after stopping or reducing a drug.

Brain stem

Structures on top of the spinal cord that control basic survival functions like breathing and heart rate.

Medulla oblongata

Brain stem structure controlling heart rhythm, blood flow, breathing rate, and digestion.

Reticular activating system

Nerve network inside the brain stem controlling arousal, consciousness, and the ability to focus attention; damage can cause coma.

Cerebellum

The "little brain" at the rear of the brainstem; controls balance, coordination, and fine motor movement.

Cerebral cortex

Thin outer layer of densely packed neurons (gray matter); the brain's control and information-processing center, divided into two hemispheres.

Limbic system

Set of forebrain structures (thalamus, hypothalamus, pituitary gland, hippocampus, amygdala) governing emotion and basic drives.

Thalamus

Limbic structure that relays sensory information (all senses except smell) from the spinal cord to other parts of the forebrain.

Hypothalamus

Limbic structure that regulates hunger, thirst, body temperature, and sexual arousal, and serves as the brain's reward center.

Pituitary gland

The body's "master gland," controlled by the hypothalamus; located at the base of the brain and produces many hormones.

Hippocampus

Limbic structure responsible for processing and storing memories.

Amygdala

Limbic structure responsible for aggression, fear, and recognizing emotional facial expressions.

Corpus callosum

Band of fibers connecting the two hemispheres, allowing them to communicate.

Occipital lobes

Rear lobes of the brain that control visual information and processing; contain the visual cortex.

Temporal lobes

Side lobes of the brain that control auditory processing, memory, facial recognition, and language comprehension (Wernicke's area).

Parietal lobes

Lobes near the back crown of the brain containing the somatosensory cortex (touch) and association areas that organize information.

Somatosensory cortex

Area of the parietal lobe that receives and processes touch sensations from across the body.

Association areas

Cortex regions that process and organize information rather than handling sensory or motor input directly.

Frontal lobes

Lobes just behind the forehead controlling higher-order thinking, language production, and executive functioning, especially in the prefrontal cortex.

Prefrontal cortex

Front part of the frontal lobe involved in personality, judgment, abstract thought, and emotional processing.

Executive functioning

Capacity to plan ahead, meet goals, exercise self-control, follow multi-step directions, and stay focused despite distraction.

Motor cortex

Rear section of the frontal lobe that sends signals controlling skeletal muscle movement.

Split brain research

Study of patients whose corpus callosum was severed (often to treat severe epilepsy), revealing hemisphere specialization.

Epilepsy

Disorder caused by abnormal electrical activity in the brain (seizures); severe cases are sometimes treated by severing the corpus callosum.