A specialized cell that conducts impulses through the nervous system and contains three major parts--a cell body, dendrites, and an axon.
The part of a neuron that contains the nucleus and carries out the metabolic functions of the neuron.
In a neuron, the branchlike extensions of the cell body that recieve signals from other neurons.
The slender, tail-like extension of the neuron that transmits signals to the dendrites or cell body of other neurons and to muscles, glands, and other parts of the body.
Specialized cells in the brain and spinal cord that hold neurons together, remove waste products such as dead neurons, and perform other manufacturing, nourishing, and cleanup tasks.
The junction where the axon terminal of a sending neuron communicates with a receiving neuron across the synaptic cleft.
The slight negative electrical potential of the axon membrane of a neuron at rest, about -70 millivolts.
The sudden reversal of the resting potential, which initiates the firing of a neuron.
The white, fatty coating wrapped around some axons that acts as insulation and enables impulses to travel much faster.
A chemical substance that is released into the synaptic cleft from the axon terminal of a sending neuron, crosses a synapse, and binds to apprpriate receptor sites on the dendrites or cell body of a receiving neuron, influencing the cell either to fire or not to fire.
Protein Molecules on the surfaces of dendrites and cell bodies that have distinctive shapes and will interact only with specific neurotransmitters.
The process by which neurotransmitters are taken from the synaptic cleft back into the axon terminal for later us, thus terminating their excitatory or inhibitory effect on the receiving neuron.
A neurotransmitter that plays a role in learning new information, causes the skeletal muscle fibers to contract, and keeps the heart from beating too rapidly.
A neurotransmitter that plays a role in learning, attention, movement, and reinforcement; neurons in the brains of those with Parkinson's disease and schizophrenia are less sensitive to its effects.
A neurotransmitter that affects the metabolism of glucose and nutrient energy stored in muscles to be released during strenuous exercise.
A neurotransmitter that plays an important role in regulating mood, sleep, impulsivity, aggression, and appetite.
Chemicals produced naturally by the brain that reduce pain and the stress of vigorous exercise and positively affect mood.
Central Nervous System (CNS)
The part of the nervous system comprising the brain and the spinal cord.
Peripheral Nervous System (PNS)
The nerves connecting the central nervous system to the rest of the body.
An extension of the brain, from the base of the brain through the neck and spinal column, that transmits messages between the brain and the peripheral nervous system.
A link between the spinal cord and the brain that contains structures that regulate physiological functions, including heart rate, respiration, and blood pressure.
The structure that begins at the point where the spinal cord enlarges as it enters the brain and handles functions critical to physical survival. It includes the medulla, the pons, and the reticular formation.
The part of the brainstem that controls heartbeat, blood pressure, breathing, coughing, and swallowing.
A structure in the brainstem that plays a crucial role in arousal and attention and that screens sensory messages entering the brain.
The brain structure that helps the body execute smooth, skilled movements and regulates muscle tone and posture.
Area that contains structures linking the physiological functions of the hindbrain to the cognitive functions of the forebrain.
The largest part of the brain, where cognitive functions as well as many of the motor functions of the brain are carried out.
The structure, located above the brainstem, that acts as a relay station for information flowing into or out of the forebrain.
A small but influential brain structure that regulates hunger, thirst, sexual behavior, internal body temperature, other body functions, and a wide variety of emotional behaviors.
A group of structures in the midbrain, including the amygdala and hippocampus, that are collectively involved in emotional expression, memory, and motivation.
A structure in the limbic system that plays an important role in emotion, particularly in response to unpleasant or punishing stimuli.
A structure in the limbic system that plays a central role in the storing of new memories, the response to new or unexpected stimuli, and navigational ability.
Sympathetic Nervous System
The division of the autonomic nervous system that mobilizes the body's resources during stress and emergency, preparing the body for action.
Parasympathetic Nervous System
The division of the autonomic nervous system that brings the heightened bodily responses back to normal following an emergency.
A record of brain wave activity made by a machine called the electroencephalograph.
A small wire used to monitor the electrical activity of or stimulate activity within a single neuron.
CT Scan (computerized axial tomography)
A brain-scanning technique that uses a rotating, computerized X-ray tube to produce cross-sectional images of the structures of the brain.
MRI (magnetic resonance imagery)
A diagnostic scanning technique that produces high-resolution images of the structures of the brain.
PET Scan (position-emission tomography)
A brain-imaging technique that reveals activity in various parts of the brain, based on patterns of blood flow, oxygen use, and glucose consumption.
Functional MRI (fMRI)
A brain-imaging technique that reveals both brain structure and brain activity more precisely and rapidly than PET.
The largest structure of the human brain, consisting of the two cerbral hemispheres connected by the corpus callosum and covered by the cerebral cortex.
The right and left halves of the cerebrum, covered by the cerebral cortex and connected by the corpus callosum; they control movement and feeling on the opposing sides of the body.
The thick band of nerve fibers that connects the two cerbral hemispheres and makes possible the transfer of information and the synchronization of activity between the hemispheres.
The gray, convulted covering of the cerbral hemispheres that is responsible for the higher mental processes of language, memory, and thinking.
Areas of the cerebral cortex that house memories and are involved in thought, perception, and language.
The specialization of one of the cerebral hemispheres to handle a particular function.
The hemisphere that controls the right side of the body, coordinates complex movements, and, in most people, handles most of the language functions.
The hemisphere that controls the left side of the body and, in most people, is specialized for visual-spatial perception.
A surgical procedure, performed to treat severe cases of epilepsy, in which the corpus callosum is cut, separating the cerebral hemispheres.
The largest of the brain's lobes, which contain the motor cortex, Broca's area, and the frontal association areas.
The strip of tissue at the rear of the frontal lobes that controls voluntary body movement and participates in learning and cognitive events.
The area in the frontal lobe, usually in the left hemisphere, that controls the production of speech sounds.
An impairment in the physical ability to produce speech sounds or, in extreme cases, an inability to speak at all; caused by damage to Broca's area.
The lobes that contain the somatosensory cortex (where touch, pressure, temperature, and pain register) and other areas that are responsible for body awareness and spatial orientation.
The strip of tissue at the front of the parietal lobes where touch, pressure, temperature, and pain register in the cerebral cortex.
The lobes that are involved in the reception and interpretation of visual information; they contain the primary visual cortex.
Primary Visual Cortex
The area at the rear of the occipital lobes where vision registers in the cerbral cortex.
The lobes that are involved in the reception and interpretation of auditory information; they contain the primary auditory cortex, Wernicke's area.
Primary Auditory Cortex
The part of each temporal lobe where hearing registers in the cerebral cortex.
The language area in the left temporal lobe involved in comprehending the spoken word and in formulating coherent speech and written language.
Aphasia that results from damage to Wernicke's area and in which the person's speech is fluent and clearly articulated but does noto make sense to listeners.
The process through which the developing brain eliminates unnecessary or redundant synapses.
A system of ductless glands in various parts of the body that manufacture hormones and secrete them into the bloodstream, thus affecting cells in other parts of the body.
A chemical substance that is manufactured and released in one part of the body and affects other parts of the body.
The endocrine gland located in the brain that releases hormones that activate other endocrine glands as well as growth hormone; "master gland."
A pair of endocrine glands that release hormones that prepare the body for emergencies and stressful situations and also release corticoids and small amounts of the sex hormones.
The segments of DNA that are located on the chromosomes and are the basic units for the transmission of all hereditary traits.
Rod-shaped structures in the nuclei of body cells, which contain all the genes and carry all the genetic information necessary to make a human being.
A set of inheritance rules in which the presence of a single dominant gene causes a trait to be expressed but two genes must be present for the expression of a recessive trait.
A pattern of inheirtance in which a trait is influenced by both genes and environmental factors.