Biological psychologists
type of psychologists that study the links between our biology and our behavior.
dendrite
bushy fibers that are part of the neurons that receive information and conduct impulses toward the cell body
axon
the neuron's extension that passes messages through its branching terminal fibers that form junctions with other neurons, muscles, or glands.
neuron
a nerve cell; the basic building block of the nervous system.
action potential
a neural impulse; a brief electrical charge that travels down an axon.
threshold
The level of stimulation to required to trigger a neural impulse. An all or nothing mechanism.
synapse
the junction between the axon tip of the sending neuron and the dendrite of or cell body of the receiving neuron.
neurotransmitters
chemical messengers that cross the synaptic clefts between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate
endorphins
natural opiate-like neurotransmitters linked to pain control and pleasure. Helps explain good feelings such as "runner's high", the painkilling effects of acupuncture, and the indifference to pain in some severely injured person.
acetylcholine
neurotransmitter that enables muscle action, learning, and memory.
dopamine
neurotransmitter that influences movement, learning, attention, and emotion.
serotonin
neurotransmitter that affects mood, hunger, sleep, and arousal. undersupply can lead to depression.
norepinephrine
Helps control alertness and arousal.
endorphin
natural opiate that lessens pain and boosts mood.
agonist
these molecules are similar enough to neurotransmitters to bind to its receptor and mimic its effects. These excite the neurons' firing.
antagonist
these molecules bind to receptors, but their effect is to block a neurotransmitters functioning.
nervous system
the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
central nervous system
the brain and spinal cord make up this system
peripheral nervous system
the sensory and motor neurons that connect the central nervous system to the rest of the body.
nerves
bundled axons that form 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 brain and spinal cord.
motor neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
interneurons
neurons within the brain and spinal cord 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. also called the "skeletal nervous system
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. When they act on the brain, they influence our interest in sex, food, and aggression.
adrenal glands
a 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.
pituitary gland
the endocrine system's most influential gland. Under the influence of the hypothalamus, this gland regulates growth and controls other endocrine glands.
lesion
tissue destruction. it is naturally or experimentally caused destruction of brain tissue.
brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions. the base is the medulla.
medulla
the base of the brainstem; controls breathing and heartbeat.
thalamus
Sitting at the top of the brainstem, this joined pair of egg-shaped structures acts as the brain's sensory switchboard. It receives information from all the senses except smell and routes it to higher brain regions that deal with seeing, hearing, tasting
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 some nonverbal learning, processing sensory input, and coordinating movement output and balance.
limbic system
neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.
amygdala
two lima-bean-sized neural clusters in the limbic system that are linked to emotion, particularly aggression and fear.
hypothalamus
a neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps to govern the endocrine system via the pituitary gland, and is linked to emotion and reward.
cerebral cortex
the intricate fabric of interconnected neural cells covering the cerebral hemispheres; a thin surface layer that is 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 and in making plans and judgements.
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 position.
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 auditory areas, each receiving information primarily from the opposite ear.
motor cortex
an area at the rear of the frontal lobes that controls voluntary movements.
sensory cortex
area at the front of the parietal lobes that registers and processes body touch and movement sensations.
association areas
areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, speaking, and integrating information.
aphasia
impairment of language, usually caused by left-hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area ( impairing understanding).
Broca's area
controls language expression; an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.
Wernicke's area
controls language reception; a brain area, usually in the left temporal lobe, that is involved in language comprehension and expression.
plasticity
The brain's ability to modify itself after some types of damage, by reorganizing after damage or by building new pathways based on experience.
neurogenesis
the formation of new neurons.
corpus callosum
the large band of neural fibers connecting the two brain hemispheres, and carrying messages between them.
split brain
a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.