| A | B |
|---|
| stimulus | The change or signal in the environment that can make an organism react. |
| response | What your body does in reaction to a stimulus. |
| neurons | The cells that carry information through the nervous system are called…. |
| nerve impulse | The message that a neuron carries is called…. |
| dendrite | An extension that carries impulses toward the cell body. |
| axon | Carries impulses away from the cell body. |
| nerve | A bundle of nerve fibers is called….. |
| sensory neuron | Picks up stimuli from the internal or external environment or convert each stimulus into a nerve impulse. |
| motor neuron | Sends an impulse to a muscle, and the muscle then contracts. |
| interneuron | A neuron that carries nerve impulses from one neuron to another is called… |
| synapse | The tiny space between the axon of one neuron and the dendrite of another neuron is called… |
| brain | The part of the central system that controls most functions in the body is called the….. |
| spinal cord | The thick column of nerve tissue that links the brain to most of the nerves in the peripheral nervous system is called the …… |
| cerebrum | Interprets input from the senses, controls the movement of skeletal muscles, and carries out complex mental processes such as learning, remembering, and making is called the ….. |
| cerebellum | Coordinates the actions of the muscles and helps the body to keep the balance. |
| brainstem | Controls body’s involuntary activities such as breathing and heartbeat. |
| peripheral nervous system | It consists of a network of nerves that branch out from the central nervous system and connect it to the rest of the body. It has a total of 43 pairs of nerves. |
| somatic nervous system | The nerves of this system control voluntary actions – activities you can choose to do or not to do. |
| autonomic nervous system | The nerves of this system control involuntary actions such as adjusting the diameter of blood vessels. |
| 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 | It is behind the cornea, the opening through which lights enters the eye. |
| iris | It is around the pupil, a circular structure that regulates the amount of light entering the eye. |
| lens | It is a flexible structure that focuses light. |
| retina | A layer of receptor cells that line the back of the eye. Light hitting the retina causes nerve impulses to begin. |
| eardrum | It is a membrane that vibrates when sound waves strike it. |
| cochlea | It is a snail-shaped tube lined with receptors that respond to sound. |
| semicircular canals | Structures that is responsible for your sense of balance. |
