 | Term | Definition |
| |
stimulus |
any change or signal in the environment that can make an organism react |
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response |
what your body does in reaction to a stimulus |
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neurons |
cells that carry information through your nervous system |
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nerve impulse |
the message neurons carry |
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dendrites |
carry impulses toward the neuron's cell body |
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axon |
carries impulses away from the cell body |
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nerve |
a bundle of nerve fibers |
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sensory neuron |
picks up stimuli from the internal or external environment and converts each stimulus into a nerve impulse |
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interneuron |
a neuron that carries nerve impulses from one neuron to another |
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motor neuron |
sends an impulse to a muscle or gland and the muscle or gland reacts in reponse |
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synapse |
the junction where one neuron can transfer an impulse to another structure |
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central nervous system |
the half of your nervous system that consists of the brain and the spinal cord |
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peripheral nervous system |
the half of your nervous system that includes all the nerves located outside of the central nervous system |
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brain |
controls most of the functions in the body |
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spinal cord |
a thick column of nervous tissue that links the brain to most of the nerves in the peripheral nervous system |
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cerebrum |
the largest part of the brain that interprets input from the senses, controls movement, and carries out complex mental processes such as learning and remembering |
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cerebellum |
the second largest part of the brain that coordinates muscle action and balance |
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brian stem |
lies beneath the cerebrum and cerebellum and controls your body's involuntary actions |
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somatic nervous system |
the half of the peripheral nervous system that control voluntary actions |
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autonomic nervous system |
the half of the peripheral nervous system that controls involuntary actions |
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reflex |
a response that occurs automatically |
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concussion |
a bruise-like injury of the brain |
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cornea |
the clear tissue that covers the front of the eye |
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pupil |
the opening through which light enters the eye |
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iris |
a circular structure that surrounds the pupil and regulates the amount of light entering the eye |
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lens |
a flexible structure that focuses light |
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retina |
a sheet of light sensitive cells that line the back of the eye |
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rod cells |
enable you to see black and white and work best in dim light |
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cone cells |
allow you to see color and work best in bright light |
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optic nerve |
a short thick nerve that rods and cones use to send electrical impulses to the brain |
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eardrum |
vibrates when struck by sound waves (aka tympanic membrane) |
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hammer |
a small bone in the middle ear that transmits vibrations from the eardrum to the anvil; also called the malleus |
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anvil |
a small bone in the middle ear that transmits vibrations from the hammer to the stirrup; also called the "incus" |
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stirrup |
a small bone in the middle ear that transmits vibrations from the anvil to a membrane of the inner ear; also called the "stapes" |
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cochlea |
a snail-shaped tube that is lined with receptor cells that respond to sound |
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semicircular canals |
structures in the ear that are responsible for your sense of balance |
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taste buds |
organs on your tongue that respond to chemicals in food |
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drug |
any chemical taken into the body that causes changes in a person's body or behavior |
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drug abuse |
deliberate misuse of drugs for purposes other than medical ones |
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tolerance |
a state in which a drug user needs larger and larger amounts of the drug to produce the ame effect on the body |
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addiction |
a condition in which the body becomes physically dependent on a drug |
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withdrawal |
a period of adjustement that occurs when a person stops taking a drug on which the body is dependant |
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depressants |
drugs that slow down the activity of the central nervous system |
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stimulants |
they speed up the body processes |
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alcoholism |
a disease in which a person is both physically addicted to and emotionally dependent on alcohol |
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What is the function of your nervous system? |
it receives information, responds to information, and maintains homeostasis |
| |
What is homeostasis? |
the maintenance of stable internal conditions in an organism |
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What are the 3 kinds of neurons? |
sensory, interneuron, motor |
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What must the nerve impulses cross to be carried along? |
it must cross over the gap between the axon and the next structure |
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What organs are included in the central nervous system? |
brain, spinal cord |
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What are the three main regions of the brain? |
cerebrum, cerebellum, brain stem |
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What does the peripheral nervous system consist of? |
a network of nerves that branch out from the central nervous system |
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What is the reflex arc? |
1. your sensory neurons detect a pain stimulus 2. your nerve impulses travel to your spinal cord 3. your nerve impulses return to motor neurons and you move whatever body part is hurt 4. as you pull away your nerve impulses travel to your brain and you feel the pain |
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What are the two ways the central nervous system can be damaged? |
concussion and spinal cord injuries |
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How does the eye work? |
they respond to the stimulus of light. they convert that stimulus into impulses that your brain interprets, enabling you to see. |
| |
What does the eye do? |
it converts sounds to nerve impulses that your brain then interprets |
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What controls your sense of balance? |
structures in your inner ear (semicircular canals |
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How do smell and taste work together? |
they both depend on chemicals in food or in the air. the chemicals trigger responses in receptors in the nose and mouth. |
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What does skin contain? |
it contains many touch receptors and the receptor respond to many stimuli |
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Why are most abused drugs dangerous? |
because they have immediate effects on the brain and other parts of the nervous system |
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What are some commonly abused drugs? |
depressants, stimulants, inhalants, hallucinogens, anabolic steroids, and alcohol |
| |
What can alcohol use do to you? |
it can destroy cells in the brain and liver, and it can lead to addiction |
