Myelinand

MultipleSclerosis

Myelin – The insulating sheath surrounding nerve cells

•Discovered in 1854 by Rudolf Virchow•Composed of lipid fats and proteins•Surrounds axons, creating a coat called the Myelin sheath•Increases the speed of impulses by containing the current•Speed of a myelinatedaxon is 5-30 meters per second•Speed of unmyelinated axon is .5-2 meters per second

•The myelin sheath enables neurons to conduct electric impulses in order to convey messages across the brain efficiently•Nodes of Ranvier are parts of the myelin sheath that are broken along the axon•Myelin is considered the “white matter” of the brain because the the Oligodendrocyte cells give it a white appearance.

Myelin – The insulating sheath surrounding nerve cells

Myelin – The insulating sheath surrounding nerve cells

•When a child is born, very few pathways are myelinated•Myelination continues up until age 20 •Neurons will not function properly unless myelinated, which is what leads to multiple sclerosis

Multiple SclerosisMultiple Sclerosis, or MS, is caused when the myelin sheaths around axons is damaged, which in turn creates demyelination. Because the myelin sheath is damaged, the axons can no longer communicate or send messages to each other. There are a variety of symptoms that come with MS, such as loss of sensitivity, muscle weakness, problems in speech or with swallowing, and many others.

• The cause of Multiple Sclerosis is unknown, but researchers are focusing on disorders in the immune system.

• Researchers believe that a virus of some sort alters the immune system to make it believe that myelin is a foreign intruder, thus making the immune system attack it.

Multiple Sclerosis

• Multiple Sclerosis requires physical and neurologic tests to diagnose.

• MRIs are used to scan the brain, and to look for things such as brain legions.

• Electro-physcological tests are conducted to test impulses traveling through the nerves. If they are traveling slower than usual, perhaps the myelin has been damaged.

• Another test doctors can conduct is examining the cerebral-spinal fluid that surrounds the brain, making sure that there are no abnormal chemicals or antibodies that could suggest the presence of MS.

Multiple Sclerosis

Awesome Video!!!!!!

• http://video.about.com/ms/Multiple-Sclerosis.htm

Bibliography

Pictures:•http://www.aurorahealthcare.org/yourhealth/healthgate/getcontent.asp?URLhealthgate=%2222566.html%22•http://medical-dictionary.thefreedictionary.com/myelin+sheath

Information:•http://myelin.org/•http://www.mult-sclerosis.org/myelin.html•http://www.vaccinetruth.org/myelin_sheath.htm•http://www.medicinenet.com/multiple_sclerosis/page4.htm Multiple Sclerosis•http://en.wikipedia.org/wiki/Multiple_sclerosis Multiple Sclerosis