Myers' Psychology for the AP Course 4th Edition - Unit 1: Introduction to Psychology (Modules 1.1-1.3)

nature-nurture issue

the longstanding controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors. Today's science sees traits and behaviors arising from the interaction of nature and nurture

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

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

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

genome

the complete instructions for making an organism

identical (monozygotic) twins

individuals who developed from a single fertilized egg that split in two, creating two genetically identical organisms

fraternal (dizygotic) twins

individuals who developed from separate fertilized eggs. They are genetically no closer than ordinary siblings, but shared a prenatal environment.

interaction

the interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity)

epigenetics

"above" or "in addition to" (epi) genetics; 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)

brain and spinal cord

peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

nerves

bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs

sensory (afferent) neurons

neurons that carry incoming information from the body's tissues and sensory receptors to the brain and spinal cord

motor (efferent) neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

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). Its sympathetic division arouses; its parasympathetic division calms.

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

reflex

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

neuron

a nerve cell; the basic building block 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; enables vastly greater transmission speed as neural impulses hop from one node to the next

glial cells (glia)

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

action potential

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

threshold

the level of stimulation required to trigger a neural impulse

refractory period

in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state

all-or-none response

a neuron's reaction of either firing (with a full-strength response) or not firing.

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

reuptake

a neurotransmitter's reabsorption by the sending neuron

endorphins

"morphine within"—natural, opiate-like neurotransmitters linked to pain control and to pleasure.

agonist

a molecule that increases a neurotransmitter's action

antagonist

a molecule that inhibits or blocks a neurotransmitter's action

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream

hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues

psychoactive drug

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

substance use disorder

disorder characterized by continued substance craving and use despite significant life disruption and/or physical risk

depressants

drugs that reduce neural activity and slow body functions

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

addiction

an everyday term for compulsive substance use (and sometimes for dysfunctional behavior patterns, such as out-of-control gambling) that continue despite harmful consequences

withdrawal

the discomfort and distress that follow discontinuing the use of an addictive drug or behavior

barbiturates

drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgement

opioids

opium and its derivatives, such as morphine and heroin; depress neural activity, temporarily lessening pain and anxiety

stimulants

drugs that excite neural activity and speed up body functions

hallucinogens

psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input

near-death experience

an altered state of consciousness reported after a close brush with death (such as through cardiac arrest); often similar to drug-induced hallucinations