Weiten Ch 3

Front 1

Action potential

Back 1

A brief change in a neuron's electrical charge.

Front 2

Adaptation

Back 2

An inherited characteristic that increased in a population (through natural selection) because it helped solve a problem of survival or reproduction during the time it emerged.

Front 3

Adoption studies

Back 3

Research studies that assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents.

Front 4

Afferent nerve fibers

Back 4

Axons that carry information inward to the central nervous system from the periphery of the body.

Front 5

Agonist

Back 5

A chemical that mimics the action of a neurotransmitter.

Front 6

Antagonist

Back 6

A chemical that opposes the action of a neurotransmitter.

Front 7

Autonomic nervous system (ANS)

Back 7

The system of nerves that connect to the heart, blood vessels, smooth muscles, and glands.

Front 8

Axon

Back 8

A long, thin fiber that transmits signals away from the neuron cell body to other neurons, or to muscles or glands.

Front 9

Behavior

Back 9

Any overt (observable) response or activity by an organism.

Front 10

Behavioral genetics

Back 10

An interdisciplinary field that studies the influence of genetic factors on behavioral traits.

Front 11

Central nervous system (CNS)

Back 11

The brain and the spinal cord.

Front 12

Cerebral cortex

Back 12

The convoluted outer layer of the cerebrum.

Front 13

Cerebral hemispheres

Back 13

The right and left halves of the cerebrum.

Front 14

Cerebrospinal fluid (CSF)

Back 14

A solution that fills the hollow cavities (ventricles) of the brain and circulates around the brain and spinal cord.

Front 15

Chromosomes

Back 15

Threadlike strands of DNA (deoxyribonucleic acid) molecules that carry genetic information.

Front 16

Corpus callosum

Back 16

The structure that connects the two cerebral hemispheres.

Front 17

Critical period

Back 17

A limited time span in the development of an organism when it is optimal for certain capacities to emerge because the organism is especially responsive to certain experiences.

Front 18

Dendrites

Back 18

Branchlike parts of a neuron that are specialized to receive information.

Front 19

Dominant gene

Back 19

A gene that is expressed when paired genes are heterozygous (different).

Front 20

Efferent nerve fibers

Back 20

Axons that carry information outward from the central nervous system to the periphery of the body.

Front 21

Electrical stimulation of the brain (ESB)

Back 21

Sending a weak electric current into a brain structure to stimulate (activate) it.

Front 22

Electroencephalograph (EEG)

Back 22

A device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp.

Front 23

Endocrine system

Back 23

A group of glands that secrete chemicals into the bloodstream that help control bodily functioning.

Front 24

Endorphins

Back 24

The entire family of internally produced chemicals that resemble opiates in structure and effects.

Front 25

Evolutionary psychology

Back 25

Theoretical perspective that examines behavioral processes in terms of their adaptive value for a species over the course of many generations.

Front 26

Excitatory PSP

Back 26

An electric potential that increases the likelihood that a postsynaptic neuron will fire action potentials.

Front 27

Extraverts

Back 27

People who tend to be interested in the external world of people and things.

Front 28

Family studies

Back 28

Scientific studies in which researchers assess hereditary influence by examining blood relatives to see how much they resemble each other on a specific trait.

Front 29

Fight-or-flight response

Back 29

A physiological reaction to threat in which the autonomic nervous system mobilizes the organism for attacking (fight) or fleeing (flight) an enemy.

Front 30

Fitness

Back 30

The reproductive success (number of descendants) of an individual organism relative to the average reproductive success of the population.

Front 31

Forebrain

Back 31

The largest and most complicated region of the brain, encompassing a variety of structures, including the thalamus, hypothalamus, limbic system, and cerebrum.

Front 32

Fraternal twins

Back 32

Twins that result when two eggs are fertilized simultaneously by different sperm cells, forming two separate zygotes. Also called Dizygotic twins.

Front 33

Genes

Back 33

DNA segments that serve as the key functional units in hereditary transmission.

Front 34

Genetic mapping

Back 34

The process of determining the location and chemical sequence of specific genes on specific chromosomes.

Front 35

Genotype

Back 35

A person's genetic makeup.

Front 36

Heterozygous condition

Back 36

The situation that occurs when two genes in a specific pair are different.

Front 37

Hindbrain

Back 37

The part of the brain that includes the cerebellum and two structures found in the lower part of the brainstem: the medulla and the pons.

Front 38

Homozygous condition

Back 38

The situation that occurs when two genes in a specific pair are the same.

Front 39

Hormones

Back 39

The chemical substances released by the endocrine glands.

Front 40

Hypothalamus

Back 40

A structure found near the base of the forebrain that is involved in the regulation of basic biological needs.

Front 41

Identical twins

Back 41

Twins that emerge from one zygote that splits for unknown reasons. Also called Monozygotic twins.

Front 42

Inclusive fitness

Back 42

The sum of an individual's own reproductive success plus the effects the organism has on the reproductive success of related others.

Front 43

Inhibitory PSP

Back 43

An electric potential that decreases the likelihood that a postsynaptic neuron will fire action potentials.

Front 44

Learning

Back 44

A relatively durable change in behavior or knowledge that is due to experience.

Front 45

Lesioning

Back 45

Destroying a piece of the brain.

Front 46

Limbic system

Back 46

A densely connected network of structures roughly located along the border between the cerebral cortex and deeper subcortical areas.

Front 47

Midbrain

Back 47

The segment of the brain stem that lies between the hindbrain and the forebrain.

Front 48

Monogamy

Back 48

A mating system in which one male and one female mate exclusively, or almost exclusively, with each other.

Front 49

Mutation

Back 49

A spontaneous, heritable change in a piece of DNA that occurs in the individual organism.

Front 50

Myelin sheath

Back 50

Insulating material, derived from glial cells, that encases some axons of neurons.

Front 51

Natural selection

Back 51

Principle stating that heritable characteristics that provide a survival reproductive advantage are more likely than alternative characteristics to be passed on to subsequent generations and thus come to be “selected“ over time.

Front 52

Nerves

Back 52

Bundles of neuron fibers (axons) that are routed together in the peripheral nervous system.

Front 53

Neurons

Back 53

Individual cells in the nervous system that receive, integrate, and transmit information.

Front 54

Neurotransmitters

Back 54

Chemicals that transmit information from one neuron to another.

Front 55

Parasympathetic division

Back 55

The branch of the autonomic nervous system that generally conserves bodily resources.

Front 56

Parental investment

Back 56

What each sex invests-in terms of time, energy, survival risk, and forgone opportunities-to produce and nurture offspring.

Front 57

Perceptual asymmetries

Back 57

Left-right imbalances between the cerebral hemispheres in the speed of visual or auditory processing.

Front 58

Peripheral nervous system

Back 58

All those nerves that lie outside the brain and spinal cord.

Front 59

Phenotype

Back 59

The ways in which a person's genotype is manifested in observable characteristics.

Front 60

Pituitary gland

Back 60

The “master gland“ of the endocrine system; it releases a great variety of hormones that fan out through the body, stimulating actions in the other endocrine glands.

Front 61

Polyandry

Back 61

A mating system in which each female seeks to mate with multiple males, while each male mates with only one female.

Front 62

Polygenic traits

Back 62

Characteristics that are influenced by more than one pair of genes.

Front 63

Polygyny

Back 63

A mating system in which each male seeks to mate with multiple females, while each female mates with only one male.

Front 64

Population

Back 64

The larger collection of animals or people from which a sample is drawn and that researchers want to generalize about.

Front 65

Postsynaptic potential (PSP)

Back 65

A voltage change at the receptor site on a postsynaptic cell membrane.

Front 66

Primary sex characteristics

Back 66

The sexual structures necessary for reproduction.

Front 67

Puberty

Back 67

The period of early adolescence marked by rapid physical growth and the development of sexual (reproductive) maturity.

Front 68

Recessive gene

Back 68

A gene whose influence is masked when paired genes are different (heterozygous).

Front 69

Refractory period

Back 69

A time following orgasm during which males are largely unresponsive to further stimulation.

Front 70

Resting potential

Back 70

The stable, negative charge of a neuron when it is inactive.

Front 71

Reuptake

Back 71

A process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane.

Front 72

Secondary sex characteristics

Back 72

Physical features that are associated with gender but that are not directly involved in reproduction.

Front 73

Soma

Back 73

The cell body of a neuron; it contains the nucleus and much of the chemical machinery common to most cells.

Front 74

Somatic nervous system

Back 74

The system of nerves that connect to voluntary skeletal muscles and to sensory receptors.

Front 75

Split-brain surgery

Back 75

A procedure in which the bundle of fibers that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures.

Front 76

Sympathetic division

Back 76

The branch of the autonomic nervous system that mobilizes the body's resources for emergencies.

Front 77

Synapse

Back 77

A junction where information is transmitted from one neuron to the next.

Front 78

Synaptic cleft

Back 78

A microscopic gap between the terminal button of a neuron and the cell membrane of another neuron.

Front 79

Terminal buttons

Back 79

Small knobs at the end of axons that secrete chemicals called neurotransmitters.

Front 80

Thalamus

Back 80

A structure in the forebrain through which all sensory information (except smell) must pass to get to the cerebral cortex.

Front 81

Twin studies

Back 81

A research design in which hereditary influence is assessed by comparing the resemblance of identical twins and fraternal twins with respect to a trait.

Front 82

Zygote

Back 82

A one-celled organism formed by the union of a sperm and an egg.