AP Psychology: Heredity, Environment, Nervous System, and Neurons

A complete deck of AP Psychology vocabulary flashcards covering heredity, environment, nervous system divisions, neuron structure, neural firing, neurotransmitters, hormones, and psychoactive drugs.

Heredity (Nature)

The passing down of genetic information from parents to offspring, setting the foundation and increasing the likelihood for behavioral tendencies, mental traits, memory, problem-solving skills, and predispositions to mental health conditions.

Environmental Factors (Nurture)

All external influences encountered throughout life—including family interactions, education, culture, socioeconomic status, and exposure to chemical or biological substances—that interact with genetic makeup to shape traits and behaviors.

Testosterone

A genetically regulated sex hormone present in males and females where higher levels correlate with higher rates of aggression, pursuit of effort, risk taking, and shorter lifespans.

Estrogen

A sex hormone whose quantity is regulated genetically alongside testosterone and plays a significant role in biology and behavior.

Evolutionary Factors

Behavioral and personality traits passed down through natural selection as theorized by Charles Darwin, enabling ancestors to survive and reproduce.

Central Nervous System (CNS)

The division of the nervous system responsible for facilitating electrochemical communication between the brain and body through spinal cord fluids.

Peripheral Nervous System (PNS)

The sensory nerves and body tissues outside the CNS that relay sensory messages to the brain through the central nervous system.

Somatic Nervous System

A subgroup of the peripheral nervous system that enables voluntary muscle movement through motor neurons and relays sensory signals to the brain via sensory neurons.

Autonomic Nervous System

A largely uncontrollable subgroup of the peripheral nervous system that operates automatically to regulate functions such as heart beating, food digestion, and organ movement.

Sympathetic Nervous System

A branch of the autonomic nervous system that arouses the body and expends energy during fight or flight responses.

Parasympathetic Nervous System

A branch of the autonomic nervous system that calms the body system, slows heartbeat, and lowers blood sugar after arousal.

Neuron (Nerve Cell)

A specialized cell that operates via electrochemistry to send and receive signals throughout the nervous system, consisting of a soma, axon, dendrites, myelin sheath, and synapses.

Soma

The cell body of a neuron containing DNA and other essential structures required to keep the neuron alive.

Axon

The part of a neuron through which electrochemical messages travel toward the axon terminals.

Dendrites

Branch-like extensions of a neuron that receive neurochemicals released from the synapses of other neurons.

Myelin Sheath

A fatty layer covering the axon of a neuron that insulates nerve fibers and speeds signal transmission.

Glial Cells

Cells that support and protect neurons by providing structural support, insulating nerve fibers, maintaining homeostasis, removing waste during sleep, and assisting in signal transmission.

Reflex Arc

A spinal cord neural pathway involving sensory neurons, interneurons, and motor neurons that triggers a quick, involuntary action without involving the brain.

Sensory Neurons

Neurons that detect stimuli and transmit sensory information from the peripheral nervous system to the spinal cord.

Interneurons

Neurons located within the spinal cord that process incoming sensory input and form connections between sensory neurons and motor neurons.

Motor Neurons

Neurons that carry response signals from the spinal cord to muscles or glands to produce movement or action.

Resting Potential

The stable, negative internal charge maintained by a neuron relative to its external environment when at rest.

Action Potential

A neural impulse or electrical signal triggered when a neuron receives a stimulus that reaches the threshold.

Threshold

The critical level of stimulation required to trigger an action potential in a neuron.

Depolarization

The phase of neural firing when ion channels open to allow a rapid influx of positive ions, making the internal charge less negative and eventually positive.

All-or-Nothing Basis

The principle stating that a neuron fires completely if the stimulus reaches threshold, and does not fire at all if threshold is not met.

Refractory Period

A temporary recovery phase following an action potential during which a neuron cannot fire again, ensuring one-way impulse movement.

Reuptake

The process by which excess neurotransmitters in the synapse are reabsorbed by the pre-synaptic neuron for future use.

Excitatory Neurotransmitters

Neurotransmitters that increase the likelihood that a receiving neuron will fire an action potential.

Inhibitory Neurotransmitters

Neurotransmitters that decrease the likelihood that a receiving neuron will fire an action potential.

Dopamine

A neurotransmitter involved in reward, motivation, memory, attention, and regulation of body movements.

Serotonin

A neurotransmitter contributing to feelings of well-being and happiness, while regulating mood, appetite, digestion, sleep, memory, and sexual desire.

Norepinephrine

A neurotransmitter and hormone involved in the fight or flight response that increases heart rate, blood pressure, and blood flow to muscles.

Glutamate

The most abundant excitatory neurotransmitter in the brain and central nervous system, essential for synaptic plasticity, learning, and memory.

GABA (Gamma-Aminobutyric Acid)

The primary inhibitory neurotransmitter in the brain that reduces neuronal excitability, promotes relaxation, and reduces stress and anxiety.

Endorphins

Neurotransmitters produced by the central nervous system and pituitary gland that function as natural painkillers.

Substance P

A neurotransmitter involved in transmitting pain signals from the peripheral nervous system to the central nervous system, as well as in inflammation and stress responses.

Acetylcholine

A neurotransmitter involved in muscle contraction, arousal, attention, memory, and learning.

Hormones

Slow, systemic chemical signals that travel through the bloodstream to act on body tissues, taking days or weeks to take effect or linger.

Adrenaline

A hormone released by the adrenal glands in response to stress that increases heart rate, blood pressure, and energy supply during fight or flight.

Leptin

A hormone produced by fat cells that helps regulate energy balance by inhibiting hunger to promote satiety.

Ghrelin

A hormone produced in the stomach that stimulates appetite, increases food intake, and promotes fat storage.

Melatonin

A hormone that regulates sleep-wake cycles by signaling the body to prepare for sleep.

Oxytocin

A hormone that plays a crucial role in social bonding, sexual reproduction, childbirth, and breast milk release.

Agonists

Chemicals in drugs that bind to and activate dendrite receptors, mimicking neurotransmitters to produce associated feelings (e.g., heroin, morphine, opium).

Antagonists

Chemicals in drugs that block neurotransmitter receptors, preventing activation.

Psychoactive Drugs

Substances that alter sensory perception and mood without changing the actual incoming sensory information.

Substance Use Disorder

Continued drug use despite significant risk or maladaptation, resulting from physical and psychological addiction.

Withdrawal

The severe mental and physical discomfort and distress experienced after discontinuing an addictive drug or behavior.

Stimulants

A class of drugs that excite neural activity and accelerate body functions, increasing breathing rate, heartbeat, energy, and confidence (e.g., caffeine, nicotine, amphetamines, cocaine, ecstasy).

Depressants

A class of drugs that reduce neural activity and slow body functions, including alcohol, barbiturates, and opiates.

Alcohol

A depressant and dis-inhibitor that slows brain activity controlling judgment and inhibitions, reduces motor coordination, and can cause long-term nerve cell death and brain shrinkage.

Hallucinogens

Drugs that distort perceptions and evoke sensory images in the absence of sensory input, such as LSD.

Opiates

Endorphin-mimicking painkillers (such as codeine, morphine, and heroin) that illicit warm, euphoric feelings and disrupt natural endorphin production.