a branch of psychology concerned with the links between biology and behavior.
neuron extensions that receive messages and conduct them toward the cell body.
neuron extension that sends messages to other neurons or cells
a nerve cell; the basic building block of the nervous system.
a nerve impulse
a junction between the a xon tip of a sending neuron and the dendrite or cell body of a receiving neuron.
level of stimulation required to trigger a neural impulse.
a neuron's reaction of either firing (with a full-strength response) or not firing.
neuron-produced chemicals that cross synapses to carry messages to other neurons or cells.
chemicals, such as opium, morphine, and heroin, that depress neural activity, temporarily lessening pain and anxiety.
"morphine within"—natural, opiatelike neurotransmitters linked to pain control and to pleasure.
the body's speedy, electrochemical communication network, consisting of all the nerve cells of the central and peripheral nervous systems.
central nervous system (CNS)
the brain and spinal cord.
peripheral nervous system (PNS)
the sensory and motor neurons connecting the central nervous system (CNS) to the rest of the body.
bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs.
neuron that carries incoming information from the sensory receptors to the central nervous system.
neuron that carries outgoing information from the central nervous system to the muscles and glands.
neuron that processes information between sensory inputs and motor outputs.
somatic nervous system
peripheral nervous system division controlling the body's skeletal muscles. Also called the skeletal nervous system.
autonomic nervous system
peripheral nervous system division controlling the glands and the muscles of the internal organs (such as the heart). Its sympathetic subdivision arouses; its parasympathetic subdivision calms.
sympathetic nervous system
autonomic nervous system subdivision that arouses the body, mobilizing its energy in stressful situations.
parasympathetic nervous system
autonomic nervous system subdivision that calms the body, conserving its energy.
the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream.
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.
pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
most influential endocrine gland. Under the influence of the hypothalamus, the ____ regulates growth and controls other endocrine glands.
device that uses electrodes placed on the scalp to record waves of electrical activity sweeping across the brain's surface.
PET (position emission tomography) scan
a view of brain activity showing where a radioactive form of glucose goes while the brain performs a given task.
MRI (magnetic resonance imaging)
a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy.
fMRI (functional MRI)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. ____ scans show brain function.
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; responsible for automatic survival functions.
the base of the brainstem; controls heartbeat and breathing.
area at the top of the brainstem; directs sensory messages to the cortex and transmits replies to the cerebellum and medulla.
nerve network running through the brainstem and thalamus; plays an important role in controlling arousal.
the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance.
neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.
two lima-bean-sized neural clusters in the limbic system; linked to emotion.
a neural structure lying below (hypo) the thalamus; directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion.
thin layer of interconnected neurons covering the cerebral hemispheres; the body's ultimate control and information-processing center.
portion of the cerebral cortex lying just behind the forehead; in volved in speaking and muscle movements and in making plans and judgments.
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.
portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.
portion of the cerebral cortex lying roughly above the ears; includes areas that receive information from the ears.
cerebral cortex area at the rear of the frontal lobes; controls voluntary movements.
cerebral cortex area at the front of the parietal lobes; registers and processes body touch and movement sensations.
false sensory experience, such as hearing something in the absence of an external auditory stimulus.
cerebral cortex area involved primarily in higher mental functions, such as learning, remembering, thinking, and speaking.
frontal lobe area, usually in the left hemisphere, that directs the muscle movements involved in speech; controls language expression.
brain area, usually in the left temporal lobe, involved in language comprehension and expression; controls language reception.
the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.
formation of new neurons.
large band of neural fibers connecting the two brain hemispheres and carrying messages between them.
condition in which the brain's two hemispheres are isolated by cutting the fibers (mainly those of the corpus callosum) connecting them.
our awareness of ourselves and our environment.
focusing conscious awareness on a particular stimulus.
failure to see visible objects when our attention is directed elsewhere.
internal biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.
REM (rapid eye movement) sleep
recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.
relatively slow brain waves of a relaxed, awake state.
periodic, natural, reversible loss of consciousness—as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation. (Adapted from Dement, 1999.)
recurring problems in falling or staying asleep.
sleep disorder in which a person has uncontrollable sleep attacks, sometimes lapsing directly into REM sleep.
a sleep disorder in which a sleeping person repeatedly stops breathing until blood oxygen is so low it awakens the person just long enough to draw a breath.
sequence of images, emotions, and thoughts passing through a sleeping person's mind.
according to Freud, the remembered story line of a dream.
the tendency for REM sleep to increase following REM sleep deprivation.