0
sausage links
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
Are muscles and glands myelinated?
Muscles and glands are not myelinated. It is the axon of a neuron that is myelinated. The myelin forms a layer called myelin sheath that makes the nervous system function properly.
Would conduction speed of a nerve fiber be the fastest in a large or small myelinated fiber?
Yes. Myelinated fibers have a myelin sheath around them which keeps the impulse from scattering and on a direct path. This makes the impulse travel faster than unmyelinated fibers.
White matter of the nervous system is composed of?
White matter in the nervous system is caused when the axons in the area are myelinated. This means that the axons have a fatty protein covering to provide insulation. The myelin sheath is composed of special cells calls Schwann Cells.
What is meant when axon is described as myelinated?
Most axons are covered with a protective sheath of myelin, a substance made of fats and protein, which insulates the axon. Myelinated axons conduct neuronal signals faster than do unmyelinated axons.
What is non-myelinated nerve fiber?
a nerve fiber that lacks the fatty myelin insulating sheath. Such fibers form the gray matter of the nervous system, as distinguished from the white matter of myelinated fibers. Also called nonmedullated nerve fiber.
The axons of some neurons have an insulating coating called?
This is called myelin or myelin sheath. It's made mainly from fat with a few proteins in it, and is produced by oligodendrocyte cells in the CNS and schwann cells in the peripheral nervous system. It speeds up nerve signalling by allowing action potentials (the electric currents that make up nerve impulses) to skip between the gaps in the myelin (nodes of ranvier). In unmyelinated axons, sodium and potassium channels have to create the voltage differences at every single step along the nerve. (Say for example 100 times per nerve). Myelinated neurones only need to create these voltage differences at the nodes of ranvier (where sodium and potassium ion channels are located on myelinated neurones) Say for example there are 10 nodes of ranvier on a myelinated axon. The unmyelinated axon must create this voltage difference 10 times more frequently than the myelinated axon, hence the nerve impulse travels 10 times faster in a myelinated axon. (Based on the random numbers I used. In real life the numbers may be wildly different, but they still work in this way).
What is Saltatory conduction made possible by?
Saltatory conduction is made possible by myelinated nerve fibers. This is the means through which one node of Ranvier will communicate with the next.
Does a worm have a myelinated or non-myelinated neuron?
non-myelinated
What contains myelinated axons?
Myelinated Fibers.
Are dendrites always myelinated?
No. They are almost never myelinated, but can be.
Which neuron is never myelinated?
Neurons that do not have a myelin sheath must use continuous conduction, which is slower. These are the smaller axons of the CNS, as well as some types of fine sensory fibers, such as olfactory nerves.
What is the insulating layer wrapped around nerve cells that increases the speed of nerve impulse transmission?
The myelin sheath. Due to its insulating properties, the myelin sheath prevents the movement of ions in nerve cells. Therefore nervous impulses will jump between the gaps in the myelin sheath (called the Nodes of Ranvier). This is a lot quicker than the conduction in non-myelinated nerve fibres which occurs by the movement of ions across each of the nerve cell membranes.
