1. WARM UP 3/8 1. Use Na+, receptors, Ach, action potential, neuromuscular junction in a sentence. 2. List 5 things you learned on the internet assignment. 3. What is the function of the nervous system?

2. NOTES Ch 10 3/8 The nervous system intro

3. NERVOUS SYSTEM FUNCTION: 1. Communication 2. Integration – (making body systems work together)

4. PARTS Brain, spinal cord, nerves

5. 2 MAIN TYPES OF CELLS 1. Neurons – nerve cells 2. Neuroglia (glia) – special connective tissue cells

6. 4 MAIN TYPES OF GLIA 1. ASTROCYTES * helps maintain K+ balance * helps maintain K+ balance

7. 2. MICROGLIA * destroy microbes * destroy microbes

8. 3. OLIGODENDROGLIA * hold nerve fibers together * hold nerve fibers together * produce myelin sheath * produce myelin sheath

9. 4. SCHWANN CELLS * form covering on some nerves * form covering on some nerves

11. 3 MAIN TYPES OF NEURONS 1. AFFERENT sensory neurons – take impulses to spinal cord or brain (pick up info through receptors) 2. EFFERENT motor neurons– take impulses away from spinal cord or brain to effectors (muscles and glands) 3. INTERNEURONS – carry information between afferent and efferent neurons

12. STRUCTURE OF A NEURON 1. CELL BODY (SOMA) – main part of neuron; contains nucleus

13. 2. AXON – end that sends messages away from the neuron * ends – synaptic knobs * ends – synaptic knobs 3. DENDRITES – ends that receive messages * ends receptors * ends receptors

16. 4. MYELIN SHEATH – wraps around the axon in some neurons for insulation; makes impulse travel faster Unmyelinated – no sheath Unmyelinated – no sheath Myelinated – has sheath Myelinated – has sheath

18. 5. NODE OF RANVIER – spaces between each Schwann cell

19. PURPOSE: impulses can jump from one node to the next; makes impulse faster SALTATORY CONDUCTION – when impulse leaps from one node to another

20. 6. SCHWANN CELL – each unit on the axon that is wrapped

21. IMPULSES CAN TRAVEL UP TO 280 MPH!

22. DRAWING A NEURON Draw a picture of a neuron and label