The nervous system is composed of
the _____, ______ ____ and ______.
The brain and spinal cord make up the
central nervous system.
brain
spinal cord
nerves
Nerves carry information from the ______ to the _______ _______ ______and from the central nervous system to appropriate _______, making them contract.
senses
central nervous system
muscles
The central nervous system sorts out information from ___ ______ and sends nerve impulses to _______ which contract, making an appropriate response.
the senses
muscles
A ______ ______ is a rapid, automatic response to a stimulus. It usually has a ___________ function.
reflex action
protective
A ______ ___ is an arrangement of nerve cells which allows a speedy flow of information between the _____ ______, the _______ _______ _______ and ________.
reflex arc
sense organs
central nervous system
muscles
Stages of a reflex arc
a) The ________ is detected by sensory receptors in the sense organs;
stimulus
Stages of a reflex arc
b) _____ ________ are sent along a sensory nerve to the central nervous system
Nerve impulses
Stages of a reflex arc
c) The impulse is passed to a relay nerve cell in the central nervous system which in turn passes it to a _____ _____ ____
motor nerve cell
Stages of a reflex arc
d) The motor nerve cell passes the nerve impulse to the appropriate muscles which respond by ________