psych unit 1

Psychology

science of behavior and mental processes

Nature-nurture issues

long standing controversy over relative contributions that genes and experience make to develop psychological traits and behaviors.

Natural selection

principle that inherited traits enabling organism to survive and reproduce in a particular environment will be passed on to succeeding generations

Evolutionary psychology

study of evolution of behavior and mind, using principles of natural selection

Behavior genetics

study of relative power and limits of genetic and environmental influences on behavior

Mutation

random error in gene replication that leads to a change

Environment

every nongenetic influence, from prenatal nutrition to experiences

Heredity

genetic transfer of characteristics from parents to offspring

Genes

biochemical units of heredity

Genome

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 only shared prenatal environment

Interaction

interplay that occurs when effect of one factor depends on another factor

Epigenetics

study of molecular mechanism by which environments can influence genetic expression without DNA change

Nervous system

body’s communication network, consisting of all nerve cells of peripheral and central nervous systems

Central nervous system (CNS)

brain and spinal cord

Peripheral nervous system (PNS)

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

Neurons

bundled axons that form neural cables connecting central nervous system with muscles, glands, sensory organs

Sensory (afferent) neurons

carry incoming info from body’s tissues and sensory receptors to brain and spinal cord

Motor (efferent) neurons

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

Interneurons

neurons within brain and spinal cord; communicate internally and process info between sensory inputs and motor outputs

Somatic (skeletal) nervous system

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

Autonomic nervous system (ANS)

part of PNS that controls glands and muscles of internal organs

Sympathetic nervous system

division of ANS that arouses body, mobilizing energy

Parasympathetic nervous system

division of ANS that calms body, conserving energy

Reflex

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

Neuron

nerve call; basic building block of nervous system

Cell body

part of neuron containing nucleus, cell’s life support center

Dendrites

neuron’s bush, branching extension; receive and integrate messages, conducting impulses toward cell body

Axon

segmented neuron extension that passes messages through its branches to other neurons, muscles, or glands

Myelin sheath

fatty tissue layer segmentally encasing exons of some neurons; enables faster transmission

Glial cells (glia)

cells in nervous system that support neurons, may play role in learning

Action potential

neural impulse; brief electrical charge that travels down axon

Threshold

level of stimulation required to trigger neural impulse

Refractory period

in neural processing, brief resting pause that occurs after neuron fired

All-or-none response

neuron’s reaction of either firing or not firing

Synapse

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

Neurotransmitters

chemical messengers that cross synaptic gap between neuron, influence whether neuron will generate neural impulse

Reuptake

neurotransmitter’s reabsorption by sending neuron

Endorphins

natural opioid-like neurotransmitters linked to pain control and pleasure

Agonist

molecule that increases neurotransmitter’s action

Antagonist

molecule that inhibits or blocks a neurotransmitter’s action

Endocrine system

body’s “slow” chemical communication system; secretes hormones into bloodstream

Hormones

chemical messengers manufactured by endocrine glands, travel through bloodstream, affect other tissues

Psychoactive drug

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

Substance use disorder

characterized by continued substance use despite resulting life disruption

Depressants

drugs that reduce neural activity and slow body functions

Tolerance

diminishing effect with regular use of the same dose of drug, requiring larger and larger doses

Addiction

term for compulsive substance use (or dysfunctional behavior patterns) that continues despite harmful consequences

Withdrawal

discomfort and distress that follow discontinuing an addictive drug or behavior

Barbiturates

drugs that depress CNS activity, reducing anxiety but impairing memory and judgement

Opioids

opium and derivatives; depress neural activity, temporarily lessening pain and anxiety

Stimulants

drugs that excite neural activity and speed up body functions

Hallucinogens

psychedelic drugs that distort perceptions and evoke sensory images in the absence of sensory input

Near-death experience

altered state of consciousness reported after close brush with death; often similar to drug-induced hallucinations

Acetylcholine

neurotransmitter; enables muscle action, learning, helps with memory

Substance P

neurotransmitter; helps with transmitting pain signals from sensory nerves to CNS

Dopamine

neurotransmitter; helps with movement, learning, attention, emotions

Serotonin

neurotransmitter; impacts hunger, sleep, arousal, mood

Endorphins

neurotransmitter; help pain control, impact pain tolerance

Norepinephrine

increases blood pressure, heart rate, alertness, helps with fight or flight response

Glutamate

helps with long term memory and learning

GABA

neurotransmitter; helps with sleep, movement, slows down nervous system