AP Psychology Unit 1a: Biological Bases of Behavior Vocabulary

Comprehensive vocabulary flashcards covering AP Psychology Unit 1a (Topics 1.1 through 1.5): Biological Bases of Behavior, including genetics, the nervous system, neural firing, neurotransmitters, the endocrine system, psychoactive drugs, brain structures, and states of consciousness.

Nature (in the context of “nature vs. nurture”)

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

Nurture (in the context of “nature vs. 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 trait variations) most likely be passed on to succeeding generations.

Mutation

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

Environment

Every nongenetic 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 information 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 receive and integrate messages, conducting impulses toward the cell body.

Axon

The segmented neuron 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 neural 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, nourish, 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.

Action potential

A neural impulse; a brief electrical charge that travels down an axon.

All-or-nothing principle

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.

Reuptake

A neurotransmitter’s reabsorption by the sending neuron.

Neurotransmitters

The chemical messengers of the nervous system.

Refractory period

A brief resting pause that occurs after a neuron has fired; subsequent action potentials 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-immune 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 neurotransmitters

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 a neurotransmitter’s action.

Dopamine

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

Norepinephrine

Neurotransmitter that helps control alertness and arousal.

GABA

A major inhibitory neurotransmitter; undersupply linked to seizures.

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 seizures.

Endorphins

Neurotransmitters that influence the perception of pain and pleasure.

Substance P

Neurotransmitter involved in pain perception and immune response.

Acetylcholine (ACh)

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 tissue 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, activates 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.

Reuptake 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

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

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 consequences.

Depressants

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

Alcohol

A commonly-used depressant that slows brain activity that controls judgment 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); produces distortions 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.

Withdrawal

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

Biological psychology

The scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.

Brain plasticity (neuroplasticity)

The brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.

EEG (Electroencephalogram)

An amplified recording of the waves of electrical activity sweeping across the brain's surface. These waves are measured by electrodes placed on the skin.

fMRI (Functional magnetic resonance imaging)

A technique for revealing blood flow and brain activity by comparing successive MRI scans; this scan shows brain function and as well as structure.

Lesion

Damaged or destroyed brain tissue; intentionally used as a tool to research the functions of different parts of the brain.

Split brain

A condition resulting from surgery that separates the brain’s two hemispheres by cutting the fibers connecting them.

Hindbrain

Consists of the medulla, pons, and cerebellum; directs essential survival functions, such as breathing, sleeping, and wakefulness, as well as coordination and balance.

Midbrain

Found atop the brainstem; controls some motor movement and transmits auditory and visual information.

Forebrain

Consists of the cerebral cortex, thalamus, and hypothalamus; manages complex cognitive activity, sensory and associative functions, and voluntary motor activities.

Brainstem

The oldest part (evolutionarily) and the central core of the brain; where the spinal cord enters the skull; responsible for autonomic survival functions.

Medulla (oblongata)

The base of the brainstem; controls involuntary basic life functions like heartbeat and breathing.

Reticular formation (reticular activating system)

A nerve network that travels through the brainstem into the thalamus; it filters information and plays an important role in controlling arousal; this is where nerve cells “cross over” from one side of the body to the opposite side of the brain.

Cerebellum

The “little brain” at the rear of the brainstem; functions include processing sensory input and coordinating movement and balance, as well as enabling nonverbal learning and memory.

Limbic system

Neural system located mostly in the forebrain – below the cerebral hemispheres – that includes the hippocampus, amygdala, thalamus, pituitary gland, and hypothalamus; associated with emotions and drives.

Thalamus

The forebrain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

Hypothalamus

A limbic system neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system, and is linked to emotion and reward.

Pituitary gland

The “master gland” of the endocrine system; communicates with the hypothalamus; sends messages to other glands; regulates growth.

Hippocampus

“Seahorse”-shaped neural center in the limbic system helps process explicit (conscious) memories – of facts and events – for storage.

Amygdala

Two small bean-sized (“almond”) neural clusters in the limbic system; linked to emotions like fear and aggression.

Corpus callosum

The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Frontal lobes

The portion of the cerebral cortex lying just behind the forehead; they enable linguistic processing and muscles movements, higher-order thinking, and executive functioning (such as making plans and judgments); doesn’t fully develop in most humans until roughly age 25.

Occipital lobes

The portion of the cerebral cortex lying at the back of the head; it includes areas that receive information from the visual fields.