Chapter 3 Unit 1

• neurons


  individual cells in the nervous system that receive, integrate, and transmit information
• soma


  cell body, contains the cell nucleus and much of the chemical machinery common to most cells
• dendrites


  parts of a neuron that are specialized to receive information
• axon


  long, thin fiber that transmits signals away from the soma to other neurons or to muscles or glands
• terminal buttons


  small knobs that secrete chemicals called neurotransmitters
• synapse


  a junction where information is transmitted from one neuron to another
• glia


  cells found throughout the nervous system that provide various types of support for neurons
• resting potential


  a neuron's stable, negative charge when the cell is inactive
• action potential


  a very brief shift in a neuron's electrical charge that travels along an axon
• absolute refractory period


  minimum length of time after an action potential during which another action potential cannot begin
• 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
• reuptake


  a process in which neurotransmitters are sponged up from the synaptic cleft by the presynaptic membrane
• agonist


  a chemical that mimics the actions of a neurotransmitter
• antagonist


  a chemical that opposes the action of a neurotransmitter
• peripheral nervous system


  made up of all those nerves that lie outside the brain and spinal cord.
• nerves


  bundles of neuron fibers that are routed together in the peripheral nervous system
• somatic nervous system


  made up of nerves that connect to voluntary skeletal muscles and to sensory receptors
• efferent neurons


  neurons that carry information outward from the central nervous system to the periphery of the body
• autonomic nervous system


  made up of nerves that connect to the heart, blood vessels, smooth muscles, and glands
• sympathetic division


  branch of the autonomic nervous system that mobilizes the body's resources for emergencies
• parasympathetic division


  branch of the ANS that generally conserves bodily resources
• central nervous system (CNS)


  consists of the brain and spinal cord
• 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 electric 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


  includes the cerebellum and two structures found in the lower part of the brain stem: the medulla and the pons
• medulla


  largely controls unconscious but vital functions including circulating blood, breathing, maintaining muscle tone, and regulating reflexes such as sneezing, coughing, and salivating.
• pons


  includes a bridge of fibers that connects the brainstem with the cerebellum. contains several clusters of cell bodies involved with sleep and arousal
• cerebellum


  large and deeply folded structure located next to the back surface of the brainstem. The cerebellum is critical to the coordination of movement and to the sense of equilibrium.
• midbrain


  segment of the brainstem that lies between the hindbrain and the forebrain. Contains an area that's concerned with integrating sensory processes such as vision and hearing
• reticular formation


  runs through both the hindbrain and the midbrain. Contributes to the modulation of muscle reflexes, breathing, and pain perception. Best known for role in regulation of sleep and arousal
• forebrain


  largest and most complex region of the brain, encompassing a variety of structures, including the thalamus, hypothalamus, limbic system, and cerebrum
• cerebrum


  the center of complex thought. largest and most complex part of the human brain. includes the brain areas that are responsible for the most complex mental activities, including learning, remembering, thinking, and consciousness itself
• cerebral cortex


  wrinkled surface of the cerebrum-- the outer layer of the brain. the intricately folded outer layer of the cerebrum.
• thalamus


  a structure in the forebrain through which all sensory information except smell must pass to get to the cerebral cortex. plays an active role in integrating information from various senses
• hypothalamus


  found near the base of the forebrain. involved in the regulation of basic biological needs. Contains various clusters of cells that have many key functions such as controlling the ANS. Also serves as a vital link between the brain and the endocrine system
• endocrine system


  a network of hormone-producing glands. consists of glands that secrete chemicals into the bloodstream that help control bodily functioning
• limbic system


  loosely connected network of structures located roughly along the border between the cerebral cortex and deeper subcortical areas. Not a well defined anatomical system with clear boundaries. one of the areas in the brain that appears to be rich in pleasure centers