2. THE NERVOUS SYSTEM HOW DOES IT WORK?

3. Function of the nervous system  Controls and coordinates functions throughout the body  How?  By responding to external and internal stimuli !  List 3 external stimuli:  Temperature  Texture  Brightness  List 2 internal stimuli:  Heartbeat  Peristalsis

4.  Neurons  Special cell that transmits impulses (Nerve cells!)  3 TYPES  Sensory  From sense organs to brain and SC (Spinal Cord)  Motor  From brain and SC to muscles and glands  Interneurons  Interconnect other two types http://www.rainbowstudio.com

5. Neurons: The Video Clip

6. Parts of a Neuron

8. The Nervous System How is it made up?

9. Divisions of the Nervous System The nervous system is divided into 2 main parts:The nervous system is divided into 2 main parts: –The Central Nervous System (CNS) –The Peripheral Nervous System (PNS) http://www.morphonix.com/software/education/science/brain/game/specimens/nervous_system.html

10. CNS and PNS: The Video Clip

11. The Central Nervous System (CNS) Consists of:Consists of: –The brain –The spinal cord

12. Brain: The Video Clip

13. The Brain CerebrumCerebrum –Largest part of brain –All voluntary movements controlled here –Memory “center” –Left side of brain deals with right side of body and vice versa –Your “gray matter”!

14. The Brain CerebellumCerebellum –Second largest region –Coordination and balance Brain stemBrain stem –Connects brain to spinal cord –Consists of Medulla oblongata (heart rate, breathing while sleeping, involuntary digestive stuff, etc)Medulla oblongata (heart rate, breathing while sleeping, involuntary digestive stuff, etc) ThalamusThalamus –Receives messages from sense organs HypothalamusHypothalamus –Control center for hunger, fatigue, body temp

15. PARTS OF THE BRAIN

16. BRAIN CONTROL What parts of the brain control what???????

17. The Spinal Cord Communication link between brain and rest of bodyCommunication link between brain and rest of body REFLEXES are processed hereREFLEXES are processed here Reflex arc =Reflex arc = –Stimuli (ex. a tack) –A Receptor –Sensory Neuron –Motor Neuron –An Effector (ex. Muscle)

18. Peripheral Nervous System (PNS) TWO FUNCTIONSTWO FUNCTIONS –TRANSFER IMPULSES FROM SENSE ORGANS  CNS –TRANSFER IMPULSES FROM CNS  MUSCLES OR GLANDS Can you remember which neurons are involved?Can you remember which neurons are involved? Good! Motor neurons!Good! Motor neurons!

19. Peripheral Nervous System (PNS) TWO PARTSTWO PARTS –SOMATIC NS VOLUNTARY MOVEMENTSVOLUNTARY MOVEMENTS –AUTONOMIC NS INVOLUNTARY ACTIONSINVOLUNTARY ACTIONS –HEARTBEAT (cardiac muscle) –GLAND STIMULATION