The Nervous System

1. The Nervous System Provides memory, coordination, and our ability to LEARN!

2. Parts of the Nervous System • Brain • Spinal Cord • Nerves • Sense organs (eye, ears, nose, tongue, skin)

3. Functions of the Nervous System • Receives or gathers information from ONE or more of the five senses • Responds to the stimulus Stimulus- any change in an organisms environment that makes them react (seeing the ruler drop) Response- what you do in reaction to a stimulus (grasping the ruler) • Homeostasis • The regulation of steady, life-maintaining conditions inside an organism, despite changes in its environment

4. Nerve cells are called • Neurons ( Noo rahnz) Cells that carry information through your nervous system • Basic functioning units of the nervous system • Neurons carry a message to different parts of the body. This is called an Impulse.

5. Structure of a Neuron http://ilearn.senecac.on.ca/aahs/health/IHP/ottawa/anatomy/neuron/map/neuron.html

6. http://35.9.122.184/images/40-AnimalStructureAndFunction/

7. Neurons • Made up of a cell body and branches called dendrites and axons • Dendrites receive messages from other neurons and send them to the cell body • Axons carry messages away from the cell body

8. Any message carried by a neuron is called an impulse Any message carried by a neuron is called an impulse

9. Neurons A message carried by a neuron is called an impulse

11. Types of Neurons • Sensory • Motor • Interneuron

12. Sensory Neurons • Receive information • Send impulses to the brain or spinal cord

13. Interneurons • Send impulses from sensory neurons to motor neurons

14. Motor Neurons • Conduct impulses from the brain or spinal cord to muscles or glands throughout your body

15. Synapse • Small space across which an impulse moves from an axon to the dendrites or cell body of another neuron

16. Synapse • An impulse reaches the end of an axon • Axon releases a chemical • Flows across the synapse • Stimulates the impulse in the dendrite of the next neuron • Impulse moves from neuron to neuron

17. http://www.med.harvard.edu/publications/On_The_Brain/Volume7/Number1/images/Neuron.jpghttp://www.med.harvard.edu/publications/On_The_Brain/Volume7/Number1/images/Neuron.jpg

18. An impulse moves in only one direction across a synapse - from an axon to the dendrites or cell body of another neuron. http://mhln.com

19. Two Parts • Central (CNS) • Peripheral (PNS)

20. http://inside.salve.edu/walsh/cns_pns.jpg

21. Central Nervous System • Brain • Spinal cord

22. The Brain • Coordinates body activities • Made up of approximately 100 billion neurons • Divided into three major parts- • the cerebrum • the cerebellum • the brain stem.

24. Cerebrum • Largest part of the brain • Thinking • Memory is stored • Movements are controlled • Impulses from the senses are interpreted.

26. Cerebellum • Interprets stimuli from eyes, ears, muscles • Controls voluntary muscle movements • Maintains muscle tone • Helps maintain balance

28. Brain Stem • Connects brain to spinal cord • Made up of the midbrain, the pons, • Act as pathways connecting various parts of the brain with each other • Medulla • controls involuntary actions

29. http://www.cbituk.org/GRAPHICS/brain.gif

30. The Spinal Cord • Extension of the brain stem • Bundles of neurons that carry impulses from all parts of the body to the brain and from the brain to all parts of your body

31. The Peripheral Nervous System Your brain and spinal cord are connected to the rest of your body by the peripheral nervous system. The PNS is made up of 12 pairs of nerves from your brain called cranial nerves, and 31 pairs from your spinal cord called spinal nerves. Spinal nerves are made up of bundles of sensory and motor neurons bound together by connective tissue. For this reason, a single spinal nerve can have impulses going to and from the brain at the same time. Some nerves contain only sensory neurons, and some contain only motor neurons, but most nerves contain both types of neurons. Somatic and Autonomic Systems The peripheral nervous system has two major divisions. The somatic system controls voluntary actions. It is made up of the cranial and spinal nerves that go from the central nervous system to your skeletal muscles. The autonomic system controls involuntary actions-those not under conscious control-such as your heart rate, breathing, digestion, and glandular functions. These two divisions, along with the central nervous system, make up your body's nervous system. Research Visit the Glencoe Science Web site at tx.science.glencoe.com for more information about the nervous system. Make a brochure outlining recent medical advances.

32. Peripheral Nervous SystemSomatic and Autonomic Nervous Systems • Connects body to brain & spinal cord • 12 pairs of nerves from your brain (cranial nerves) • 31 pairs from your spinal cord (spinal nerves) • Bundles of sensory and motor neurons held together by connective tissue

33. Somatic- voluntary muscle movement- tying shoe • Autonomic- involuntary muscle movement- digestion

34. http://www.christopherreeve.org/Research/Research.cfm?ID=178&c=21http://www.christopherreeve.org/Research/Research.cfm?ID=178&c=21

35. Reflexes • Involuntary, automatic response to a stimulus • Involves a simple nerve pathway called a reflex arc