| A | B |
|---|
| Central Nervous System CNS | Part of the nervous system consisting of the brain and spinal cord |
| Peripheral Nervous System PNS | Part of nervous system consisting of sensory receptors, sensory organs and nerves that connect to the central nervous system. |
| dendrites | Portion of neuron which sends impulses toward the cell body |
| axons | Portion of the neuron which sends impulses away from cell body |
| synapse | The gap between two or more neurons |
| reflex arc | A series of neurons that receive a stimulus and cause the body to react to it without conscious effect. |
| sensory neuron | a neuron that receives stimuli and carries impulses toward the spinal cord or brain. |
| motor neuron | a neuron that receives impulses from the central nervous system and stimulates muscles or glands |
| cerebrum | Part of brain containing major motor and sensory centers; controls voluntary muscles and thought |
| cerebellum | Part of brain that monitors and adjusts body activity for muscle tone, posture and balance. |
| brain stem | Part of brain controlling the involuntary actions. |
| cornea | clear front portion of the sclera of the eye |
| retina | innermost layer of the eye composed of light sensitive neurons |
| rods | a neuron in the retina used for vision in dim light. |
| cones | type of neuron in the retina that is sensitive to colors of light |
| cochlea | a coiled, tubular structure containing fluid and neurons that sense sound waves |
| semicircular canals | a set of three structures located in the inner ear which are responsible for balance. |
| endocrine system | a system of hormone producing glands |
| hormone | chemical produced by living cells and transported to other body tissues where it causes a specific effect. |
| pituitary gland | an endocrine gland attached to the lower part of the brain; secretes several hormones. |
