Nervous SystemBy Katie Ust

Function Control the body Sends messages from one cell to others

and from one part of the body to another

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

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.

(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.

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.

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.

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.

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