1. Nervous System By Katie Ust

2. Function  Control the body  Sends messages from one cell to others and from one part of the body to another

3. Central and Peripheral Nervous Systems Central Nervous System  Integrates information it receives  Coordinates the activity of all parts of the body  Includes the brain and spinal chord Peripheral Nervous System  Nerves and ganglia outside of the spinal chord  Connects the central nervous system to limbs and organs

4. How Nerve Impulses Work  Initially, your nerves are polarized because Na+ is on the outside of the cell wall and K+ is on the inside  While the neuron is inactive and polarized it is at it’s resting potential.  When a stimulus reaches the neuron, ion channels open allowing Na+ ions inside the cell which causes depolarization.

5. (Cont.)  Once polarization is removed the cell’s threshold is reached.  Stimulus goes above the threshold level and more Na+ ions move in. The neuron is completely depolarized, action potential is reached, and the impulse is sent through another neuron.  The refractory period occurs when ion pumps close and Na+ and K+ return to their normal sides.

6. Neurotransmitters At Synapse  Neurotransmitters are released by a neuron  They then bind to and activate receptors of another neuron at synapse, which occurs when action potential is reached.

7. Alzheimer’s Disease  Alzheimer’s is a disease caused by shrinkage mainly of the front and temporal lobes.  It causes memory loss, dementia, and can be very serious or mild, varying case to case.  Medications are sometimes used to slow Alzheimer’s, but there is no cure for the disease.

8. Broca Aphasia  This disease is caused by damage to the lower part of the left frontal lobe  Broca Aphasia impairs speech, and sometimes causes complete loss of speech.  It can be helped with speech therapy, but there is no cure.

9. Sources  Dummies.com/how- to/content/understanding-the- transmission-of-nerve-impulses.html  Sci.uidaho.edu/med532/Broca.htm  Sci.uidaho.edu/med532/Alzheimers.htm