A Newly Recognized Condition

Multiple Sclerosis (MS) is a neurologic disease that affects the Central Nervous System (CNS) through cellular immune response and the demyelination of CNS white matter (McCance et al., 2014, pp. 630–633). The initial causes of MS are unknown however, it is believed that it could possibly be due to an immune response to an initiating infection or an autoimmune response to CNS antigens on the myelin itself (Brück, 2005) (Miljković and Spasojević, 2013). MS is a result of the degradation of the myelin sheath surrounding neurons and therefore disrupts the transmission of action potentials along these cells. MS can display itself in the form of symptoms ranging from muscle weakness to trouble with sensation and coordination (NHS, 2016). The degradation of myelin leads the body to attempt to remyelinate the neurons, a process that in turn leads to the thickening of the cell by glial cells and this causes lesions to form (Chari, 2007). It is this thickening (sclerae) from which the disease gets its name. Sufferers of MS can either have a relapsing type of MS, in which there are episodes that lead to the worsening of symptoms for a period of time, or a progressive type of MS where symptoms gradually progress and worsen (McCance et al., 2014, pp. 630–633).

The central nervous system (CNS) comprises grey matter, which contains neuron cell bodies and white matter, which contains the nerve axons. Most of the nerve axons are concentrically wrapped around by lipid-rich biological membrane, known as the myelin sheath. In the CNS, myelin is produced by oligodendrocyte. a type of glial cell. (Pfeiffer et al., 1993). These electrical insulating, multilamellar membranes significantly increase the electrical resistance, in which to prevent leakage of electrical currents from the axons, as well as decrease electrical capacitance to reduce the ability of the axons to store electrical energy (Shivane &

7. Myelin Sheath whitish fatty segmented sheath around most long axons. It protects the axon, electrically insulates fibers from one another , and increases the speed of nerve impulse transmition.

Myelin, the common factor in each disease, is a subsatnce that surrounds and insulates axons on some nerve cells, allowing for a faster transporting of signals and proper functioning of the nervous system. A demyelinating disease results in the damage of nerve fibers in the brain and spinal cord due to the myelin sheath being destroyed, which is life threatening.

The central nervous system is made up of the brain and spinal cord. The brain is connected to the spinal cord. The brain helps interpret information received from the spinal cord. Through the spinal cord signals are sent to the rest of body and back to the brain. Nerve cells (neurons) are found in the nervous system and they help communicate with other cells through electrical signals. Some of the nerve cells are coated with a myelin sheath. Myelinated neurons allow electrical signals to travel at a faster speed. When the myelinated part of the nerve cell is destroyed, Multiple Sclerosis (MS) can be the one to blame.

After discovering the reading of four writers on slavery, I have learned new and exciting information about the institution of slavery. Throughout this paper I intend to inform you of there thoughts and actions and how I perceived them. I also intend to analyze how the lifestyle and upbringing of these writers affected their writing. Being able to uncover what these readings mean has been both challenging and rewarding.

There was also a theory that damage to the STN would relief some of the symptoms of Parkinson's disease and to prove this, a test was conducted on monkeys. The results were that there was an immediate relief of akinesia and bradykinesia in contralateral limbs, this was the first support of a positive role that the STN serves on hyperkinetic disorders.

Imagine a disease that has the potential to disrupt and ultimately destroy the human nervous system by attacking the myelin sheath. This is not a rare disease. In fact, it affects over 350,000 people in the United States alone (Nordqvist). The ratio of women to men that contract the disease is 2 to 1 and it is a leading cause of disability in young adults (Olek). This disease is not only widespread, it is chronic and has no known cause or cure. If disease activity is suspected an MRI is performed and, if lesions on the central nervous system are identified Multiple Sclerosis (MS) is the likely diagnosis. Despite the devastation that may follow such news, there is hope for those diagnosed

These layers are made of myelin, produced by Schwann cells that are assigned early in the organism’s development. As these layers develop they become tightly packed around the axons, and the main benefit of this coating is that it prevents the exiting and entering of ions for a distance along the axons. This protection allows the ions to travel further and cause action potentials at a faster rate (Norton and Cammer, 1984). Action potentials are caused by the influx of sodium ions followed by the slow efflux of potassium ions. The process of rapid action potentials jumping from one node to the next is called salutatory conductance (Black et al., 1991).

The damaged myelin degenerates and is engulfed by macrophages. When the affected nerves are examined under the microscope, the first abnormality to be seen is the migration of inflammatory cells and macrophages into the nerve. This is followed by destruction of the myelin. The destruction of myelin is caused by the phenomenon: molecular mimicry – where the antigen of the invading organism is similar to the antigens on the surface of the myelin sheath, then antibodies and inflammatory cells attack and damage the myelin. Inflammation and degeneration of the myelin causes leakage of proteins from the blood into the CSF, causing the increased CSF protein concentration that characterizes the disease. Also, the degenerate myelin particularly slows down the propagation of nerve impulses along your peripheral nerves; resulting in muscle weakness or paralysis. Fortunately, Schwann cells are not usually damaged; they are able to multiply and align themselves along the axon to form a new myelin sheath. This is an efficient and effective process, and full recovery can

One Schwann cell can myelinate only one axon. Oligodendrocytes and Schwann cells form myelin by wrapping around the axon. The myelin sheath is a good insulator. It also creates low capacitance.

The sclerosis is the result of scar tissue forming in the central nervous system (a process called gliosis). In part because we cannot determine in advance which nerve fibers will be affected in a particular patient--the disease can impair any part of the central nervous system--the severity of multiple sclerosis is often unpredictable. Some people may have mild problems, with no significant permanent disability. For others, multiple sclerosis means severe paralysis and confinement to a wheelchair.”

Friedreich’s Ataxia, or FA, is a disease that causes damage to the nervous system as well as mobility problems. The disease is prominently found in children. Once its onset in childhood, the disease progressively worsens, ultimately leading to impaired muscle coordination. The spinal cord, peripheral nervous system and cerebellum are the main components of the body that are affected in this disease. The spinal cord and peripheral nerves begin to degenerate which cause them to become thinner and prevent nerve impulses. Nerve impulses are responsible for the proper functioning of the body. It acts as signaling molecules and when these are prevented proper function of the body is disrupted. The cerebellum is also affected in this disease. The

Nervous tissue is established in the peripheral nerve in the body as well as the organs of the inner nervous structure which is spinal cord, brain and nerves. The cells that are present to the nervous tissue are the astragal cell astrocyte, ependymal cell, microglial cell and Schwann cell

Myelin forms around fibers along the axons that are a part of neurons. The Velocity of conducting action potentials can be increased by the myelination process which implies that oligodendrocytes in the central nervous system as well and Schwann cells wrap the axon in myelin. In this process there are layers of glial membrane which an insulator where myelin speeds up action potential conduction. Another way to look at Myelination is that it increases membrane resistance. When the membrane resistance increases this means depolarizing current cannot navigate through the membrane and goes through the low resistance interior. We learned that Node of Ranvier are gaps within the myelin axon which are crucial in producing currents and exchanging