Nervous System

nervous system the body system that controls and coordinates the body’s functions and its responses to stimuli

stimuli/stimulus anything in the internal or external environment that causes a response

neurons nerve cells

dendrites the part of the neuron that carries impulses toward the cell body

axon the part of the neuron that carries impulses away from the cell body

impulse an electrical signal that a neuron carries impulse

sensory neuron a neuron that picks up stimuli from the environment and sends a nerve impulse toward the brain SENSORY SENSES STIMULI

interneurons neurons found in the brain and spinal cord that carry impulses in between sensory and motor neurons IN BETWEEN

motor neuron a neuron that carries an impulse to muscles telling them to contract or relax MOTOR MOVES MUSCLES

synapse the small space between neurons through which an impulse crosses impulse

central nervous system the brain and the spinal cord

peripheral nervous system the nerves that branch out from the central nervous system

spinal cord a bundle of nerves that links the peripheral nerves and the brain

spine and vertebrae

brain the organ that controls most of the body’s activities; the main organ of the nervous system

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reflex an automatic response that occurs without conscious control

neurons stimulus path of a reflex (response to touching something hot): a. your fingers touch the hot item b. sensory ________________ in your fingertips detect a _______________

spinal cord an impulse muscles c. they send ________________ through your hand and arm to your __________________ ___________ d. your spinal cord sends an immediate response to your arm ______________

impulse from the interneurons in the SC motor impulse from the interneurons in the SC e. the __________________ causes you to quickly pull your hand away from the heat by stimulating the ______________ neurons in your arm and hand

pain brain f. other nerve impulses travel to from your spinal cord to your _____________ which sends a signal that tells your hand it feels __________________