1. T HE N ERVOUS S YSTEM The Communication System

2. T HE N ERVOUS S YSTEM FUNCTION Function: to communicate conditions within the body and the surrounding environment ◦ Stimulus – something that causes a change or response in an organism ◦ Response – any reaction or change in an organism that is caused by a stimulus.

3. T HE N ERVOUS S YSTEM F UNCTION

4. N EURON – NERVE CELL http://argosymedical.com/Nervous/samples/animations/Firing%20of%20Neurons/index.html Dendrites – receive signals from other cells Cell Body – contains the nucleus and organelles of the neuron Axon – long, slender part of neuron that carries impulse from cell body to terminals Schwann cells – produce the myelin sheath myelin sheath – fatty substance – increase speed signal travels down axon Axon Terminals – end of neuron that releases neurotransmitters to signal other neurons

5. T YPES OF N EURONS Sensory Neurons – run from sensory receptors (sight, smell, touch, taste, sound) to the CNS Interneurons – found exclusively in the spinal cord and brain (CNS) – communicate with other neurons Motor Neurons – carry information from the CNS to muscles or glands that carry out a response

6. T HE N ERVOUS S YSTEM COMPOSITION Central Nervous System ◦ Brain ◦ Spinal Cord Peripheral Nervous System ◦ Connects the central nervous system to the rest of the body through nerves

7. T HE B RAIN Cerebrum: ◦ Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, and problem solving ◦ Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli ◦ Occipital Lobe- associated with visual processing ◦ Temporal Lobe- associated with perception and recognition of auditory stimuli, memory, and speech Cerebellum is associated with regulation and coordination of movement, posture, and balance. Brain stem is responsible for basic vital life functions such as breathing, heartbeat, and blood pressure.

8. T HE B RAIN ( DOMINANCE )

9. T HE S PINAL C ORD A bundle of nerves that passes through the bones of the vertebrae down the back. It sends sensations to the brain from the body, and returns motor commands to the various parts of the body. Responsible for most reflexes

10. P ERIPHERAL N ERVOUS S YSTEM Connects the central nervous system to the rest of the body through nerves.

11. H OMEOSTASIS The human body uses stimuli it receives from internal and external sources to make adjustments so that the body can maintain homeostasis (a constant internal environment).

12. N ERVOUS S YSTEM S UMMARY