37 terms

Life Science Chapter 15 Nervous System

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stimulus
any change or signal in the environment that an make an organism react
response
what your body does in reaction to a stimulus
neuron
a cell that is specialized to conduct nerve impulses
nerve impulse
the message that a neuron carries
dendrite
neuron fiber that receives signals and carries them toward the cell body
axon
long nerve fiber that conducts away from the cell body of the neuron
nerve
a bundle of nerve fibers
sensory neuron
picks up stimuli from the internal or external environment and converts each stimulus into a nerve impulse
interneuron
a neuron that carries nerve impulses from one neuron to another
motor neuron
Sends impulses to a muscle or a gland, causing the muscle or gland to react.
synapse
The junction where one neuron can transfer an impulse to another structurre.
central nervous system
the control center of the body including the brain and spinal cord
peripheral nervous system
consists of all the nerves located outside of the central nervous system
brain
part of the central nervous system that controls most functions in the body
spinal cord
the thick column of nerve tissue that links the brain to most of the nerves in the peripheral nervous system
cerebrum
interprets input from the senses, controls movement, and carries out complex mental processes such as learning and remembering
cerebellum
coordinates the actions of your muscles and helps you keep your balance
brain stem
The part of the brain that lies between the cerebellum and spinal cord, and controls your body's involuntary activities such as breathing and heartbeat.
somatic nervous system
A group of nerves in the peripheral nervous system that controls voluntary actions
autonomic nervous system
A group of nerves in the peripheral nervous system that controls involuntary actions.
reflex
an automatic response that occurs very rapidly and without conscious control
concussion
a bruiselike injury of the brain
cornea
the clear tissue that covers the front of the eye
pupil
the opening in which light enters the eye
iris
a circular structure that surrounds the pupil and regulates the amount of light entering the eye
lens
a flexible structure that focuses light
retina
A sheet of light-sensitive cells at the back of the eye on which an image is focused.
rods
they work best in dim light and allow you to see black, white, and shades of gray
cones
they work best in bright light and allow you to see color
(the ones that are stained blue here)
optic nerve
The short, thick nerve in the eye through which the rods and cones send electrical impulses to the brain.
eardrum
The membrane that separates the outer ear from the middle ear, and that vibrates when sound waves strike it.
hammer
a tiny bone in the middle ear that transmits the vibrations from the eardrum to the cochlea in the inner ear, aka malleus.
anvil
a tiny bone in the middle ear that transmits the vibrations from the hammer to the stirrup, aka the incus.
stirrup
a tiny bone in the middle ear that transmits the vibrations from the anvil to a membrane of the inner ear, aka stapes
cochlea
a snail shaped tube in the inner ear that is lined with receptor cells that respond to sound
semicircular canals
the structures in the inner ear that are responsible for your sense of balance
taste bud
organs on your tongue that contains receptors that detect chemicals in food