The function of the myelin sheath is to facilitate the conduction of electrical impulses through the nerve cells. The myelin sheath is made out of a modified plasma membrane that is wrapped around the nerve axon in a spiral pattern.Continue Reading
The myelin sheath is essential for the proper functioning of the nervous system. When the myelin is damaged, nerve impulses slow down, and the nerve cell begins to wither. Diseases such as multiple sclerosis can result from damaged myelin sheaths. The sheath increases the electrical resistance of the cell by a factor of 5,000, which prevents the electrical current from leaving the axon of the nerve cell. The process of forming the myelin sheath is known as mylenization. The production of myelin begins during the 14th week of fetal development, but very little myelin is found in the brain at birth.
During infancy, mylenization occurs at a rapid rate and continues until adolescence. The myelin sheath is made up of lipids and proteins, and lipids account for 70 to 80 percent of the sheath's structure. Accordingly, it is important that infants receive greater amounts of fat in their diet than their adult counterparts. Myelin was originally discovered in 1854 by Rudolf Virchow, a German doctor.Learn more about Nerves
The brain is made up largely of neurons, or nerve cells, blood vessels and glial cells. Glial cells create a supporting structure for the brain. The brain is about 60 percent fat.Full Answer >
Motor nerves are bundles of nerve cells that control muscles. They originate in the spinal column and end at the muscles that they control. One motor nerve often controls several muscles.Full Answer >
According to Neurogenetics at the University of Tennessee Health Science Center, the human body has 95 to 100 billion neurons or nerve cells. The brain alone has at least 85 billion of these cells, although estimates go as high as 1 trillion.Full Answer >
Dendrites are a part of the central nervous system that receive input from nerve cells, which are sometimes called. Multiple fibers called dendrites extend in a branchlike formation from the cell body of a neuron. When the postsynaptic terminals, or receptors, at the end of a dendrite receive neurotransmitters released by other neurons, an electric signal is transmitted through the dendrite to the cell body of the neuron.Full Answer >