Chapter 2 Key Terms Flashcards
Neuron
A specialized cell of the nervous system that receives and transmits messages.
Glial cells
Cells that remove dead neurons and waste products from the nervous system, nourish and insulate neurons, form myelin, and play a role in neural transmission of messages.
Dendrites
Root-like structures, attached to the cell body of a neuron, that receive impulses, or incoming messages, from other neurons.
Axon
A long, thin part of a neuron that transmits impulses to other neurons from bulb-shaped structures called axon terminals or terminal buttons.
Myelin
A fatty substance that insulates axons, facilitating transmission of neural impulses.
Action potential
The electrical impulse that provides the basis for the conduction of a neural impulse along an axon of a neuron
Synapse
A junction between the axon terminals of one neuron and the dendrites or cell body of another neuron.
Neurotransmitters
Chemical substances involved in the transmission of neural impulses from one neuron to another.
Receptor site
A location on a dendrite of a receiving neuron tailored to receive a neurotransmitter.
Dopamine
A neurotransmitter that affects the ability to perceive pleasure, voluntary movement, and learning and memory; it is involved in Parkinson’s disease and appears to play a role ion schizophrenia.
Serotonin
A neurotransmitter involved on emotional arousal ans sleep; deficiencies of serotonin have been linked to eating disorders, alcoholism, depression, aggression, and insomnia.
Central nervous system
The brain and spinal cord.
Peripheral nervous system
The part of the nervous system consisting of the somatic nervous system and the autonomic nervous system.
Somatic nervous system
The division of the peripheral nervous system that connects he central nervous system with sensory receptors, skeletal muscles, and the surface of the body.
Autonomic nervous system (ANS)
The division of the peripheral nervous system that regulates glands and activities such as heartbeat, respiration, digestion, and dilation of the pupils.
Sympathetic division
The branch of the ANS that is most active during emotional responses, such as fear and anxiety, that spend the body’s reserve of energy.
Parasympathetic division
The branch of the ANS that is most active during processes (such as digestion) that restore the body’s reserve of energy.
Spinal cord
A column of nerves within the spine that transmits messages from sensory receptors to the brain and from the brain to the muscles and glands throughout the body.
Electroencephalograph (EEG)
A method of detecting brain waves by means of measuring the current between electrodes placed on the scalp.
Computerized axial tomography (CAT or CT scan)
A method of brain imaging that passes a narrow X-ray beam through the head and measures the structures that reflect the beams from various angles, enabling a computer to generate a three-dimensional image.
Magnetic resonance imaging (MRI)
An imaging method that places a person in a magnetic field and uses radio waves to cause the brain to emit signals that reveal shifts in the flow of blood, which, when the brain is being scanned, indicate brain activity.
Functional MRI (fMRI)
A form of MRI that enables researchers to observe the brain “while it works” by taking repeated scans.
Cerebral cortex
The wrinkled surface area (grey matter) of the cerebrum.
Corpus callosum
A thick fiber bundle that connects the hemispheres of the cortex.
Somatosensory cortex
The section of the cortex in which sensory stimulation is projected. It lies just behind the central fissure in the parietal lobe.
Motor cortex
The section of cortex that lies in the frontal lobe, just across the central fissure from the sensory cortex; neural impulses in the motor cortex are linked to muscular responses throughout the body.
Aphasia
A disruption in the ability to understand or produce language.
Wernicke’s aphasia
A language disorder characterized by difficulty comprehending the meaning of spoken language.
Broca’s aphasia
A language disorder characterized by slow, laborious speech.
Endocrine system
The body’s system of ductless glands that secrete hormones and release them directly into the bloodstream.
Hormone
A substance secreted by endocrine gland that regulates various body functions.
Natural selection
The concept that holds that adaptive genetic variations among members of a species enable individuals with those variations to survive and reproduce.
Evolutionary psychology
The branch of psychology that studies the ways in which adaptation and natural selection are connected with mental processes and behavior.
Instinct
A stereotyped pattern of behavior that is triggered by a particular stimulus and nearly identical among members of a species, even when they are reared in isolation.
Gene
A basic unit of heredity, which is found at a specific point on a chromosome.
Chromosome
A microscopic rod-shaped body in the cell nucleus carrying genes that transmit hereditary traits from generation to generation; humans normally have 46 chromosomes.
DNA
Acronym for deoxyribonucleic acid, the substance that forms the basic material of chromosomes; it takes the form of a double helix and contains the genetic code.
Polygenic
Referring to traits that are influenced by combinations of genes.
Nature
The inborn, innate character of an organism.
Nurture
The sum total of the environmental factors that affect an organism from conception onward.
Down syndrome
A condition caused by an extra chromosome on the 21st pair and characterized by mental deficiency, a broad face, and slanting eyes.
