Biological Psychology
a branch of psychology concerned with the links between biology and behavior
Neuron
a nerve cell; the basic building block of the nervous system
Dendrite
neuron extensions that receive messages and conduct impulses toward the cell body
Axon
neuron extensions that pass messages to other neurons or cells
Action Potential
a nerve impulse
Synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
Threshold
the level of stimulation required to trigger a neural impulse
All-or-none Response
a neuron's reaction of either firing (with a full-strength response) or not firing
Neurotransmitters
neuron-produced chemicals that cross synapses to carry messages to other neurons or cells
Opiates
chemicals, such as opium, morphine, and heroin, that depresses neural activity, temporarily lessening pain and anxiety
Endorphins
morphine within" - natural, opiatelike neurotransmitters linked to pain control and to pleasure
Nervous System
the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous system
Central Nervous System
the brain and spinal cord
Peripheral Nervous System
the sensory and motor neurons connecting the central nervous system to the rest of the body
Nerves
bundled axons that formed neural "cables" connecting the central nervous system with muscles, glands, and sense organs
Sensory Neurons
neurons that carry incoming information from the sensory receptors to the central nervous system
Motor Neurons
neurons that carry outgoing information from the central nervous system to the muscles and glands
Interneurons
neurons that communicate internally and intervene between the sensory inputs and motor outputs
Somatic Nervous System
the division of the peripheral nervous system that controls the body's skeletal muscles
Autonomic Nervous System
the division of the peripheral nervous system that controls the glands and the muscles of the internal organs. sympathetic division arouses; parasympathetic division calms
Sympathetic Nervous System
the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
Parasympathetic Nervous System
the division of the autonomic nervous system that calms the body, conserving its energy
Endocrine System
the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream
Hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
Adrenal Glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress
Pituitary Gland
the endocrine system's most influential gland. Under the influence of the hypothalamus, this gland regulates growth and controls other endocrine glands
Brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; this is responsible for automatic survival functions
Medula
the base of the brainstem, controls heartbeat and breathing
Thalamus
area at the top of the brainstem, directs sensory messages to the cortex and transmits replies to the cerebellum and medulla
EEG
recording apparatus, using electrodes placed on the scalp, that records waves of electrical activity that sweep across the brain's surface
PET
a view of brain activity showing where a radioactive form of glucose goes while the brain performs a given task
MRI
a technique that uses magnetic fields and radio waves to produce computer generated images of soft tissue. These scans show brain tissue
fMRI
a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans.
Reticular Formation
a nerve network in the brainstem that plays an important role in controlling arousal
Cerebellum
the "little brain" at the rear of the brainstem, functions include processing sensory input and coordinating movement output and balance
Limbic System
neural system located below the cerebral hemispheres; associated with emotions and drives
Amygdala
two lima-beam-sized neural clusters in the limbic system; linked to emotion
Hypothalamus
a neural structure lying below the thalamus; directs several maintenance activities; helps govern the endocrine system via the pituitary gland, and is linked to emotion
Cerebral Cortex
thin layer of interconnected neurons covering the cerebral hemisphere; the body's ultimate control and information processing center
Frontal Lobes
portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements an din making plans and judgments
Parietal Lobes
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body positions
Occipital Lobes
portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields
Temporal Lobes
portion of the cerebral cortex lying roughly above the ears; includes areas that receive information from the ears
Motor Cortex
area at the rear of the frontal lobe; controls voluntary movements
Sensory Cortex
area at the front of the parietal lobes that registers and processes body touch and movement sensations
Hallucinations
false sensory experiences, such as hearing something in the absence of an external auditory stimulus
Association Areas
areas of the cerebral cortex that are primarily involved in higher mental functions such as learning, remembering, thinking, and speaking
Broca's Area
an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech; controls language expression
Wernicke's Area
a brain area, usually in the left temporal lobe, involved in language comprehension and expression; controls language reception
Plasticity
the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience
Corpus Callosum
large band of neural fibers connecting the two brain hemispheres and carrying messages between them
Split Brain
condition in which the brain's two hemispheres are isolated by cutting the fibers connecting them
Cognitive Neuroscience
subfield of psychology that studies the connections between our brain activity and the processes of thinking, knowing, remembering, and communicating
Consciousness
our awareness of ourselves and our environment
Selective Attention
focusing conscious awareness on a particular stimulus
Inattentional blindness
failure to see visible objects when our attention is directed elsewhere
Circadian Rhythm
the biological clock; regular bodily rhythms that occur on a 24-hr cycle
REM sleep
recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed, but other body systems are active
Alpha Waves
relatively slow brain waves of a relaxed, awake state
Sleep
periodic, natural, reversible loss of consciousness - as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation
Insomnia
recurring problems in falling or staying asleep
Narcolepsy
sleep disorder in which a person has uncontrollable sleep attacks, sometimes lapsing directly into REM sleep
Sleep Apnea
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
Dream
a sequence of images, emotions, and thoughts passing through a sleeping person's mind
Manifest Content
according to Freud, the remembered story line of a dream
Latent Content
according to Freud, the underlying meaning of a dream
REM Rebound
the tendency for REM sleep to increase following REM sleep deprivation