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Psychology: Themes and Variations Chapter 3 Vocab

Terms in this set (69)

Neurons
Individual cells in the nervous system that receive, integrate, and transmit information.
Soma
The cell body, contains the cell nucleus and much of the chemical machinery common to most cells.
Dendrites
The parts of a neuron that are specialized to receive information.
Axon
A long, thin fiber that transmits signals away from the soma to other neurons or to muscles or glands.
Myelin sheath
Insulating material that encases some axons.
Terminal buttons
Small knobs that secrete chemicals called neurotransmitters.
Synapse
A junction where information is transmitted from one neuron to another.
Resting potential
A neuron's stable, negative charge when the cell is inactive.
Action potential
A brief shift in a neuron's electrical charge that travels along an axon.
Absolute refractory period
The minimum length of time after an action potential during which another action potential cannot begin.
Synaptic cleft
A microscopic gap between the terminal button of one neuron and the cell membrane of another neuron.
Neurotransmitters
Chemicals that transmit information from one neuron to another.
Postsynaptic potential (PSP)
A voltage change at a receptor site on a postsynaptic cell membrane.
Excitatory PSP
A positive voltage shift that increases the likelihood that the postsynaptic neuron will fire action potentials.
Inhibitory PSP
A negative voltage shift that decreases the likelihood that the postsynaptic neuron will fire action potentials.
Reuptake
A process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane.
Agonist
A chemical that mimics the action of a neurotransmitter.
Antagonist
A chemical that opposes the action of a neurotransmitter.
Endorphins
Internally produced chemicals that resemble opiates in structure and effects.
Peripheral nervous system
All the nerves that lie outside the brain and the spinal cord.
Nerves
Bundles of neuron fibers (axons) that are routed together in the peripheral nervous system.
Somatic nervous system
Nerves that connect to voluntary skeletal muscles and to sensory receptors.
Afferent nerve fibers
Axons that carry information inward to the central nervous system from the periphery of the body.
Efferent nerve fibers
Axons that carry information outward from the central nervous system to the periphery of the body.
Autonomic nervous system (ANS)
Nerves that connect to the heart, blood vessels, smooth muscles, and glands.
Sympathetic division
The branch of the autonomic nervous system that mobilizes the body's resources for emergencies.
Parasympathetic division
The branch of the autonomic nervous system that generally conserves bodily resources.
Central nervous system (CNS)
The brain and the spinal cord.
Cerebrospinal fluid (CSF)
Nourishes the brain and provides a protective cushion for it.
Electroencephalograph (EEG)
A device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp.
Lesioning
Destroying a part of the brain.
Electrical stimulation of the brain (ESB)
Sending a weak electrical current into a brain structure to stimulate (activate) it.
Transcranial magnetic stimulation (TMS)
A new technique that permits scientists to temporarily enhance or depress activity in a specific area of the brain.
Hindbrain
The cerebellum and two structures found in the lower part of the brainstem: the medulla and the pons.
Midbrain
The segment of the brainstem that lies between the hindbrain and the forebrain.
Forebrain
The largest and most complex region of the brain, encompassing a variety of structures, including the thalamus, hypothalamus, limbic system, and cerebrum.
Thalamus
A structure in the forebrain through which all sensory information (except smell) must pass to get to the cerebral cortex.
Hypothalamus
A structure found near the base of the forebrain that is involved in the regulation of basic biological needs.
Limbic system
A loosely connected network of structures located roughly along the border between the cerebral cortex and deeper subcortical areas.
Cerebral cortex
The convoluted outer layer of the cerebrum.
Cerebral hemispheres
The right and left halves of the cerebrum.
Corpus callosum
The structure that connects the two cerebral hemispheres.
Split-brain surgery
The bundle of fibers that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures.
Perceptual asymmetries
left-right imbalances between the cerebral hemispheres in the speed of visual or auditory processing.
Endocrine system
Glands that secrete chemicals into the bloodstream that help control bodily functioning.
Hormones
The chemical substances released by the endocrine glands.
Pituitary gland
A gland that releases a great variety of hormones that fan out around the body, stimulating actions in the other endocrine glands.
Behavioral genetics
An interdisciplinary field that studies the influence of genetic factors on behavioral traits.
Chromosones
Strands of DNA (deoxyribonucleic acid) molecules that carry genetic information.
Zygote
A single cell formed by the union of a sperm and an egg.
Genes
DNA segments that serve as the key functional units in hereditary transmission.
Homozygous condition
The two genes in a specific pair are the same.
Heterozygous condition
The two genes in a specific pair are different.
Dominant gene
The gene that is expressed when paired genes are different.
Recessive gene
The gene that is masked when paired genes are different.
Genotype
A person's genetic makeup.
Phenotype
The ways in which a person's genotype is manifested in observable characteristics.
Polygenic traits
Characteristics that are influenced by more than one pair of genes.
Family studies
Studies in which researchers assess hereditary influence by examining blood relatives to see how much they resemble one another on a specific trait.
Twin studies
Studies in which researchers assess hereditary influence by comparing the resemblance of identical twins and fraternal twins with respect to a trait.
Identical (monozygotic) twins
Twins that emerge from one zygote that splits for unknown reasons.
Fraternal (dizygotic) twins
Twins that result when two eggs are fertilized simultaneously by different sperm cells, forming two separate zygotes.
Adoption studies
Studies that assess hereditary influence by examining the resemblance between adopted children and both their biological parents and their adoptive parents.
Genetic mapping
The process of determining the location and chemical sequence of specific genes on specific chromosomes.
Fitness
The reproductive success (number of descendants) of an individual organism relative to the average reproductive success in the population.
Natural selection
Heritable characteristics that provide a survival or reproductive advantage are more likely than alternative characteristics to be passed on to subsequent generations and thus come to be "selected" over time.
Adaption
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.
Inclusive fitness
The sum of an individual's own reproductive success plus the effects the organism has on the reproductive success of related others.
Critical period
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.
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