AP Psychology Essential Vocab

Nature

The idea that our behaviors and thoughts are a result of “inborn” factors like our genetic makeup.

Nurture

The idea that our behaviors and thoughts are a result of our sensations of the world around us.

Evolutionary Psychology

The study of the evolution of behavior and the mind, using principles of natural selection.

Behavior Genetics

The study of the relative power and limits of genetic and environmental influences on behavior.

Natural Selection

The principle that the inherited traits enabling an organism to survive and reproduce in a particular environment will (in competition with other traits variation) most likely be passed on to succeeding generations.

Mutation

A random error in gene replication that leads to a change.

Environment

Every non-genetic influence, from prenatal nutrition to the people and things around us.

Heredity

The genetic transfer of characteristics from parents to offspring.

Genes

The biochemical units of heredity that make up the chromosomes.

Genome

The complete instructions for making an organism, consisting of all of the genetic material in that organism’s chromosomes.

Eugenics

The pseudo-scientific view that the genetic makeup of a population can be “improved” by techniques like selective breeding and selective sterilization.

Identical (Monozygotic twins)

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

Fraternal (Dizygotic twins)

Twins who develop from separate fertilized eggs; they are genetically no closer than brothers and sisters, but they share a fetal environment.

Epigenetics

The study of the molecular mechanisms by which environments can influence genetic expression (without a DNA change).

Nervous System

The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Central Nervous System (CNS)

The brain and spinal cord.

Peripheral Nervous System (PNS)

The sensory and motor neurons that connect the central nervous system to the rest of the body.

Nerves

Bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs.

Reflex

A simple, automatic response to a sensory stimulus, such as the knee-jerk reaction.

Autonomic Nervous System

The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart).

Somatic Nervous System

The division of the peripheral nervous system that controls the body’s skeletal muscles.

Sympathetic Nervous System

The division of the autonomic nervous system that arouses the body, mobilizing its energy.

Parasympathetic Nervous System

The division of the autonomic nervous system that calms the body, controlling its energy.

Sensory (afferent neurons)

Nerves that carry information from the sensory inputs to the central nervous system.

Motor Neurons

Nerves that carry informations from our brain to our muscles and endocrine system.

Interneurons

Neurons within the brain and spinal cord that communicate between sensory inputs and motor outputs.

Neuron

A nerve cell; the building block cell of the nervous system.

Cell body

The part of a neuron that contains the nucleus; the cell’s life-support center.

Dendrites

A neuron’s often bushy, branching extensions that receives and integrate messages, conducting impulses toward the cell body.

Axon

The segmented neurons extension that passes messages through its branches to other neurons or to muscles or glands.

Myelin Sheath

A fatty tissue layer segmentally encasing the axons of some neurons; it enables vastly greater transmission speed as neutral impulses hop from on node to the next.

Synapse

The area where neurons connect and communicate with one another.

Glial cells

Cells in the nervous system that support, nourishing, and protect neurons; they may also play a role in learning, thinking, and memory.

Reflex arc

A neural pathway that doesn’t involve the brain, using sensory, motor, and interneurons.

All-or-nothing principles

A neuron’s reaction of either firing (with a full-strength response) or not firing at all.

Depolarization

The process of a neuron becoming activated, as negatively and positively- charged ions are exchanging places across an axon’s membrane.

Re uptake

A neurotransmitter’s reabsorption by the sending neuron.

Neurotransmitter

The chemical messengers of the nervous system.

Refractory period

A brief resting pause that occurs after a neuron has fired; subsequent action poterntials cannot occur until the axon returns to its resting state.

Resting potential

An axon’s non-activated state, when it’s filled with mostly negatively- charged ions and surrounded by mostly positively-charged ions.

Threshold

The level of stimulation required to trigger a neural impulse.

Multiple Sclerosis

A disease of the central nervous system with many physical and cognitive symptoms; caused by a degrading of the myelin sheaths that enable efficient neurotransmission.

Myasthenia Gravis

An auto-immuine disorder in which ACh transmission is inhibited, leading to increased muscular weakness and possible paralysis.

Excitatory Neurotransmitters

Neurotransmitters that increase the likelihood of a neuron reaching action potential.

Inhibitory Neurotransmitter

Neurotransmitters that decrease the likelihood of a neuron reaching action potential.

Antagonist

A molecule that inhibits or blocks a neurotransmitter’s action.

Agonist

A molecule that increases neurotransmitter’s action.

Dopamine

Neurotransmitter associated with muscle movement, attention, learning; excess is linked to schizophrenia; shortage is linked Parkinson’s disease.

Norepinephrine

Neurotransmitter that helps control alertness and arousal.

GABA

A major inhibitory neurotransmitter; undersupply linked to seizure.

Serotonin

Neurotransmitter that affects mood, hunger, sleep, arousal; undersupply is linked to depression.

Glutamate

A major excitatory neurotransmitter; oversupply can overstimulate the brain and produce migraines or seizure.

Endorphins

Neurotransmitters that influence the perception of pain and pleasure.

Substance P

Neurotransmitter involved in paine perception and immune response.

Acetylcholine

Neurotransmitter that enables muscle action, learning, memory; undersupply is linked to Alzheimer’s disease.

Endocrine System

The body’s “slow” chemical communication system; a set of glands and fat tissure that secrete hormones into the bloodstream.

Hormones

Messengers of the endocrine system; move through the bloodstream.

Leptin

Hormone that decreases feelings of hunger.

Melatonin

Hormone that helps regulate sleep cycles.

Adrenaline

Hormone associated with the “fight-or-flight” response, activities the sympathetic nervous system.

Ghrelin

Hormone that increases feelings of hunger.

Oxytocin

Hormone that stimulates orgasms, contractions during labor, and maternal milk production.

Psychoactive Drugs

A chemical substance that alters the brain, causing changes in perceptions and moods.

Re uptake Inhibitor

A drug that blocks reabsorption of certain neurotransmitters in the brain, increasing their levels and neurotransmission; used to treat depression, among other conditions.

Stimulants

Drug (such as caffeine, nicotine, and more the more powerful amphetamines, cocaine, and Ecstasy) that excite neural activity and speed up body function.

Caffeine

A mild stimulant that reduces drowsiness; can cause tremors and anxiety at high doses.

Cocaine

A potent stimulant associated with feelings of euphoria.

Opioids

Opium and its derivatives such as morphine and heroin; they depress neural activity, temporarily reducing pain and anxiety.

Heroin

A highly-addictive opioid; reduces feelings of pain and produces feelings of euphoria; reduces your body’s natural endorphin production.

Addiction

Compulsive substance use (and sometimes dysfunctional behavioral patterns) that continued despite harmful consequence.

Depressants

Drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body function.

Alcohol

A commonly-used depressant that slows brain activity that controls judgement and inhibitions; at lower- levels, users experience mild excitement and declines in motor and cognitive performance; at higher levels, users may lose consciousness and respiratory-areas of the brain may shut down.

Hallucinogens

Psychedelic (“mind-manifesting”) drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input.

Marijuana

A mild hallucinogen associated with a sense of well- being, relaxation, increased appetite, and cognitive impairment.

LSD

A powerful hallucinogenic drug; also known as “acid” (lysergic acid diethylamide); produce distortion in, especially, visual perception.

Tolerance

The diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect.

Withdrawl

The discomfort and distress that follow discontinuing an addictive drug or behavior.