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2021-05-17

Which of the cell types shown helps determine capillary permeability in the CNS?

Which of the cell types shown helps determine capillary permeability in the CNS?

Which of the cell types shown helps determine capillary permeability? The cilia of these cells help circulate the CSF that nourishes and cushions the brain and spinal cord.

At which point of the illustrated action potential would voltage-gated Na+ channels be mostly open but voltage-gated K+ channels be mostly closed?

Voltage-gated Na+ channels open when the membrane potential reaches threshold. Voltage-gated K+ channels would be mostly open near C. 21.

Which of the Neuroglial cell types shown are found in the peripheral nervous system?

Schwann cells

Which of the following is a factor that determines the rate of impulse?

Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon? the rate of impulse propagation depends largely on two factors, degree of myelination and axon diameter.

What is node of Ranvier and its function?

Node of Ranvier, periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses. This forces the current to travel down the nerve fibre to the unmyelinated nodes of Ranvier, which have a high concentration of ion channels.

Why is it called Node of Ranvier?

The myelin sheath of long nerves was discovered and named by German pathological anatomist Rudolf Virchow in 1854. French pathologist and anatomist Louis-Antoine Ranvier later discovered the nodes, or gaps, in the myelin sheath that now bear his name.

What is the function of a Neurofibril node?

The myelin sheath provides a protective insulating coating to certain neuron axons. This form of insulation, with the insulating neurolemmocytes separated from each other by neurofibril nodes, permits rapid saltatory impulse transmission.

Do all nerve cells have a Neurilemma?

All nerve cells have a neurilemma.

What is the difference between Neurilemma and Axolemma?

Plasma membrane around the nerve cell is called axolemma. Neurilemma is the plasma membrane of Schwann cells that surrounds the myelinated nerve fibers of peripheral nervous system and is absent in the central nervous system due to the lack of myelin sheath due to absence of Schwann cells.

What is the difference between Neurilemma and myelin sheath?

The neurilemma is underlain by the myelin sheath (also known as the medullary sheath). In the central nervous system, axons are myelinated by oligodendrocytes, thus lack neurilemma. Damaged nerve fibers may regenerate if the cell body is not damaged and the neurilemma remains intact.

Where is Neurilemma found?

Neurilemma: Neurilemma is only found in the peripheral nervous system. Myelin Sheath: Myelin sheath is found in both central nervous system and the peripheral nervous system.

What is the function of the myelin sheath?

Myelin is an insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances. This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells.

Is myelin and myelin sheath the same thing?

Myelin is made up of lipids and proteins, a fatty substance with a whitish appearance. It is made up of many concentric layers of plasma membrane to make up the myelin sheath around axons. Myelin sheath and myelin function are therefore the same, to increase the speed of nerve impulses.

What type of cell is myelin?

Myelin is made by two different types of support cells. In the central nervous system (CNS) — the brain and spinal cord — cells called oligodendrocytes wrap their branch-like extensions around axons to create a myelin sheath. In the nerves outside of the spinal cord, Schwann cells produce myelin.

What can damage the myelin sheath?

If you have multiple sclerosis (MS), a disease that causes your immune system to attack your central nervous system, your myelin sheaths can be damaged. That means your nerves won’t be able to send and receive messages as they should.

What food is good for myelin?

Natural iodine from sea vegetables not only helps with myelin repair but would also aids the liver and brain to clear out mercury and other heavy metals from the body. Vitamin B1 (Thiamine) helps to get energy into the muscles but it also helps with myelin repair.

What foods are bad for MS?

People with MS should avoid certain foods, including processed meats, refined carbs, junk foods, trans fats, and sugar-sweetened beverages.

Are eggs bad for MS patients?

With respect to the results of our study, we conclude egg and food IgE were not high in MS patients and IgE allergy against fish and egg may be very unlikely to affect MS development and intake egg and fish are not inhibited.

Is milk bad for MS?

Cow’s milk is not only high in saturated fat, but a 2010 study in the journal Autoimmune Disease found that there are two proteins in cow’s milk that can negatively affect people with MS. The reason? It stimulates immune cells and causes lesions to be created.

What vitamins should I take for multiple sclerosis?

Vitamins that seem of particular interest to people with MS include vitamin D, the antioxidant vitamins, vitamin B6 and vitamin B12.

What diet is best for multiple sclerosis?

Overall, people with MS need a balanced, low-fat and high-fiber diet. Unprocessed or naturally processed foods are preferred to processed foods. This is similar to the Mediterranean diet, and the same healthy diet that’s recommended for the general population. Also consider limiting alcohol as much as possible.