2. The Nervous System Nervous System – The entire network of neurons in the body. Includes: Central Nervous System Peripheral Nervous System Their subdivisions

3. The Central Nervous System Central Nervous System – The brain and spinal cord. “Command Central”

4. The Central Nervous System The Brain Makes complex decisions Coordinates body functions Initiates our behaviors Responsible for voluntary movements

5. The Central Nervous System The Spinal Cord Serves as a sort of neural cable, connecting the brain with parts of the peripheral nervous system extending into the trunk and limbs. Does not connect the brain to internal organs. Responsible for simple reflexes.

6. The Peripheral Nervous System The Peripheral Nervous System – Plays a supportive role, connecting the central nervous system with the rest of the body through bundles of sensory and motor axons, called nerves.

7. The Peripheral Nervous System Carries messages between the brain and: Sense Organs (eyes, ears, etc.) Internal Organs Muscles

8. The Peripheral Nervous System The “Pick-up and Delivery Service” for the Central Nervous System.

9. Divisions of the PNS Somatic Nervous System Carries sensory information to the central nervous system. Sends voluntary messages to the body’s skeletal muscles.

10. Divisions of the PNS Autonomic Nervous System Sends communication between the central nervous system and the internal organs and glands. Regulate digestion Respiration Heart Rate Arousal

11. Divisions of the PNS Sympathetic Division Part of the Autonomic nervous system Sends messages to internal organs and glands that help us respond to stressful and emergency situations.

12. Divisions of the PNS Parasympathetic Division Part of the autonomic nervous system Monitors the routine operations of the internal organs. Returns the body to calmer functioning after arousal by the sympathetic division.

13. The Nervous System and Drugs Agonist – Drug or other chemical that enhances or mimics the effects of neurotransmitters. Antagonist – Drug or other chemical that inhibits the effects of neurotransmitters.