Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account

Nervous System

an extensive network of specialized cells that carry information to and from all parts of the body.


deals with the structure and function of neurons, nerves, and nervous tissue.


basic cell that makes up the nervous system and sends essages within it

Parts of neuron

dendrites, soma, axon


branch-like structures that receive messages from other neurons


cell body of the neuron, responsible for maintaining the life of the cell


long tube-like structure that carries the neural message to other cells

glial cells

grey fatty cells that: provide support for the neurons to grow on and around, deliver nutrients to neurons, produce myelin to coat axons, and clean up waste products and dead neurons


fatty substances produced by certain glial cells that coat the axons of neurons to insulate, protect, and speed up the neural impulse.


bundles of axons in the body that travel together through the body


Schwann's membrane - Tunnel through which damaged nerve fibers can repair themselves


charged particles. Inside neuron = negative charge, outside neuron = positive charge

resting potential

state of the neuron when not firing a neural impulse

action potential

the release of the neural impulse consisting of a reversal of the electrical charge within the axon, also allows +Na ions to enter the cell


referring to the fact that a neuron either fires completely or does not fire at all

axon terminals

branches at the end of the axon

synaptic knob

rounded areas on the end of axon terminals

synaptic vesicles

sack-like structures found inside the synaptic knob containing chemicals


chemical found in the synaptic vesicles which, when released, has an effect on the next cell


memory & movement


mood, sleep, appetite


major inhibitory neurotransmitter, sleep and movement


memory formation


mood and arousel (alertness/awakeness)


sensations of pleasure


pain relief

synapse/synaptic gap

referring to the fact that a neuron either fires completely or does not fire at all

receptor sites

holes in the surface of the dendrites or certain cells of the muscles and glands, which are shaped to fit only certain neurotransmitters

excitatory neurotransmitter

neurotransmitter that causes the receiving cell to fire

inhibitory neurotransmitter

neurotransmitter that causes the receiving cell to stop firing


mimic or enhance the effects of a neurotransmitter on the receptor sites of the next cell, increasing or decreasing the activity of that cell


block or reduce a cell's response to the action of other chemicals or neurotransmitters


process by which neurotransmitters are taken back into the synaptic vesicles


a complex protein that is manufactured by cells

Central nervous system (CNS)

part of the nervous system consisting of the brain and spinal cord

spinal cord

a long bundle of neurons that carries messages to and from the body to the brain that is responsible for very fast, lifesaving reflexes

sensory neuron

a neuron that carries information from the senses to the central nervous system. Also called afferent neuron

motor neuron

a neuron that carries messages from the central nervous system to the muscles of the body. Also called efferent neuron


a neuron found in the center of the spinal cord that receives information from the sensory neurons and sends commands to the muscles through the motor neurons


the ability to constantly change both the structure and function of cell involved in trauma

peripheral nervous system (PNS)

all nerves and neurons that are not contained in the brain and spinal cord but that run through the body itself. Divided into somatic and autonomic nervous system

somatic nervous system

division of the PNS consisting of nerves that carry information from the senses to the CNS and from the CNS to the voluntary muscles of the body

sensory pathway

nerves coming from the sensory organs to the CNS consisting of sensory neurons

motor pathway

nerves coming from the CNS to the voluntary muscles, consisting of motor neurons

autonomic nervous system (ANS)

division of the PNS consisting of nerves that control all of the involuntary muscles, organs, and glands sensory pathway nerves coming from the sensory organs to the CNS consisting of sensory neurons

sympathetic division

fight-or-flight system - part of the ANS that is responsible for reacting to stressful events and bodily arousal.

parasympathetic division

part of the ANS that restores the body to normal functioning after arousal and is responsible for the day-to-day functioning of the organs and glands

deep lesioning

insertion of a thin, insulated wire into the brain through which an electrical current is sent that destroys the brain cells at the tip of the wire

electrical stimulation of the brain (ESB)

milder electrical current that causes neurons to react as if they had received a message

Electroencephalograph (EEG)

machine designed to record the brain wave patterns produced by electrical activity of the surface of the brain

computed tomography (CT)

brain-imaging method using computer controlled X-rays of the brain

magnetic resonance imaging (MRI)

brain-imaging method using radio waves and magnetic fields of the body to produce detailed images of the brain

functional MRI

computer makes a sort of "movie" of changes in the activity of the brain using images from different time periods

positron emission tomography (PET)

brain-imaging method in which a radioactive sugar is injected into the subject and a computer compiles a color-coded image of the activity of the brain with lighter colors indicating more activity

brain stem

medulla, pons, RF, cerebellum


the first large swelling at the top of the spinal cord, forming the lowest part of the brain, which is responsible for life-sustaining functions such as breathing, swallowing, and heart rate


the larger swelling above the medulla that connects the top of the brain to the bottom and that plays a part in sleep, dreaming, left-right body coordination, and arousal

reticular formation (RF)

an area of neurons running through the middle of the medulla and the pons and slightly beyond that is responsible for selective attention


part of the lower brain located behind the pons that controls and coordinates involuntary, rapid, fine motor movement

structures under the cortex

limbic system (thalamus, olfactory bulbs, hypothalamus, hippocampus, amygdala

limbic system

a group of several brain structures located under the cortex and involved in learning, emotion, memory, and motivation


part of the limbic system located in the center of the brain, this structure relays sensory information from the lower part of the brain to the proper areas of the cortex and processes some sensory information before sending it to its proper area

olfactory bulbs

two projections just under the front of the brain that receive information from the receptors in the nose located just below


small structure in the brain located below the thalamus and directly above the pituitary gland, responsible for motivational behavior such as sleep, hunger, thirst, and sex. Sits above and controls the pituitary gland (master endocrine gland)


curved structure located within each temporal lobe, responsible for the formation of long-term memories and the storage of memory for location of objects


brain structure located near the hippocampus, responsible for fear responses and memory of fear


outermost covering of the brain consisting of densely packed neurons, responsible for higher thought processes and interpretation of sensory input


wrinkling of the cortex. Allows a much larger area of cortical cells to exist in the small space inside the skull

cerebral hemispheres

the two sections of the cortex on the left and right sides of the brain

corpus callosum

thick band of neurons that connects the right and left cerebral hemispheres

4 lobes of the brain

occipital, parietal, temporal, frontal

occipital lobe

section of the brain located at the rear and bottom of each cerebral hemisphere containing the visual centers of the brain

primary visual cortex

processes visual information from the eyes

visual association cortex

identifies and makes sense of visual information

parietal lobes

sections of the brain located at the top and back of each cerebral hemisphere containing the centers for touch, taste, and temperature sensations

somatosensory cortex

area of neurons running down the front of the parietal lobes responsible for processing information from the skin and internal body receptors for touch, temperature, body position, and possibly taste

temporal lobes

areas of the cortex located just behind the temples containing the neurons responsible for the sense of hearing and meaningful speech

primary auditory cortex

processes auditory information from the ears

auditory association cortex

identifies and makes sense of auditory information

frontal lobes

areas of the cortex located in the front and top of the brain, responsible for higher mental processes and decision making as well as the production of fluent speech

motor cortex

section of the frontal lobe located at the back, responsible for sending motor commands to the muscles of the somatic nervous system

association areas

areas within each lobe of the cortex responsible for the coordination and interpretation of information, as well as higher mental processing

broca's aphasia

condition resulting from damage to Broca's area (usually in left frontal lobe), causing the affected person to be unable to speak fluently, to mispronounce words, and to speak haltingly

wernicke's aphasia

condition resulting from damage to Wernicke's area (usually in left temporal lobe), causing the affected person to be unable to understand or produce meaningful language

spatial neglect

condition produced by damage to the association areas of the right hemisphere resulting in an inability to recognize objects or body parts in the left visual field


the upper part of the brain consisting of the two hemispheres and the structures that connect them

split brain research

Study of patients with severed corpus callosum. Involves sending messages to only one side of the brain. Demonstrates right and left brain specialization

left side of brain

seems to control language, writing, logical thought, analysis, and mathematical abilities, processes information sequentially, can speak

right side of brain

controls emotional expression, spatial perception, recognition of faces, patterns, melodies, and emotions, processes information globally, cannot speak

endocrine glands

glands that secrete chemicals called hormones directly into the bloodstream


chemicals released into the bloodstream by endocrine glands

pituitary gland

gland located in the brain that secretes human growth hormone and influences all other hormone-secreting glands (also known as the master gland)

pineal gland

endocrine gland located near the base of the cerebrum that secretes melatonin

thyoid gland

endocrine gland found in the neck that regulates metabolism


endocrine gland that controls the levels of sugar in the blood


the sex glands that secrete hormones that regulate sexual development and behavior as well as reproduction


the female gonads


the male gonads

adrenal glands

endocrine glands located on top of each kidney that secrete over 30 different hormones to deal with stress, regulate salt intake, and provide a secondary source of sex hormones affecting the sexual changes that occur during adolescence


the activation of receptors in the various sense organs

sensory receptors

specialized forms of neurons

just noticeable difference (JND)

the smallest difference between two stimuli that is detectable 50 percent of the time

absolute threshold

the smallest amount of energy needed for a person to consciously detect a stimulus 50 percent of the time it is present

subliminal stimuli

stimuli that are below the level of conscious awareness. Just strong enough to activate the sensory receptors but not strong enough for people to be consciously aware of them




"below the threshold."

subliminal perception

process by why subliminal stimuli act upon the unconscious mind, influencing behavior


tendency of the brain to stop attending to constant, unchanging information

sensory adaptation

tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging


constant movement of the eyes, tiny little vibrations called that people do not notice consciously; prevents sensory adaptation to visual stimuli.


determined by the amplitude of the wave—how high or how low the wave actually is. The higher the wave, the brighter the light will be. Low waves are dimmer.


or hue, is determined by the length of the wave

visible spectrum

the portion of the whole spectrum of light that is visible to the human eye


refers to the purity of the color people see; mixing in black or gray would also lessen the saturation


clear membrane that covers the surface of the eye; protects the eye and is the structure that focuses most of the light coming into the eye

radial kerototomy

vision-improving technique that uses this fact by making small incisions in the cornea to change the focus in the eye

aqueous humor

next visual layer; clear, watery fluid that is continually replenished and supplies nourishment to the eye


hole through which light from the visual image enters the interior of the eye


round muscle (the colored part of the eye) in which the pupil is located; can change the size of the pupil, letting more or less light into the eye; helps focus the image


another clear structure behind the iris, suspended by muscles; finishes the focusing process begun by the cornea

visual accommodation

the change in the thickness of the lens as the eye focuses on objects that are far away or close

vitreous humor

jelly-like fluid called that also nourishes the eye and gives it shape


final stop for light in the eye. Contains 3 layers: Ganglion cells, Bipolar cells, Photoreceptors that respond to various light waves


visual sensory receptors found at the back of the retina, responsible for noncolor sensitivity to low levels of light


visual sensory receptors found at the back of the retina, responsible for color vision and sharpness of vision

blind spot

area in the retina where the axons of the three layers of retinal cells exit the eye to form the optic nerve, insensitive to light

dark adaptation

the recovery of the eye's sensitivity to visual stimuli in darkness after exposure to bright lights. Night blindness

light adaptation

the recovery of the eye's sensitivity to visual stimuli in light after exposure to darkness.

trichromatic theory

theory of color vision that proposes three types of cones: red, blue, and green.


images that occur when a visual sensation persists for a brief time even after the original stimulus is removed

opponent-process theory

theory of color vision that proposes four primary colors with cones arranged in pairs: red and green, blue and yellow. Lateral geniculate nucleus (LGN) of thalamus

monochrome colorblindness

either have no cones or have cones that are not working at all.

red-green colorblindess

either the red or the green cones are not working.


interpreted as frequency or pitch (high, medium, or low).


interpreted as volume (how soft or loud a sound is).


interpreted as timbre (a richness in the tone of the sound).

hertz (Hz)

cycles or waves per second, a measurement of frequency.

auditory canal

short tunnel that runs from the pinna to the eardrum (tympanic membrane).


thin section of skin that tightly covers the opening into the middle part of the ear, just like a drum skin covers the opening in a drum. When sound waves hit the eardrum, it vibrates and causes three tiny bones in the middle ear to vibrate. Hammer, Anvil, Stirrup


snail-shaped structure of the inner ear that is filled with fluid.

organ of corti

rests in the basilar membrane; contains receptor cells for sense of hearing.

auditory nerve

bundle of axons from the hair cells in the inner ear; receives neural message from the organ of Corti.


psychological experience of sound that corresponds to the frequency of the sound waves; higher frequencies are perceived as higher pitches.

place theory

theory of pitch that states that different pitches are experienced by the stimulation of hair cells in different locations on the organ of Corti.

frequency theory

theory of pitch that states that pitch is related to the speed of vibrations in the basilar membrane volley principle theory of pitch that states that frequencies above 100 Hz cause the hair cells (auditory neurons) to fire in a volley pattern, or take turns in firing.

conducting hearing impairment

an result from either: damaged eardrum (which would prevent sound waves from being carried into the middle ear properly), or damage to the bones of the middle ear (sounds cannot be conducted from the eardrum to the cochlea).

nerve hearing impairment

can result from either: damage in the inner ear, or damage in the auditory pathways and cortical areas of the brain.

cochlea implant

a microphone implanted just behind the ear picks up sound from the surrounding environment. Speech processor selects and arranges the sound picked up by the microphone. Implant is a transmitter and receiver, converting signals into electrical impulses. Collected by the electrode array in the cochlea and then sent to the brain.

taste buds

taste receptor cells in mouth; responsible for sense of taste

See more

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording