How is saltatory conduction made possible?

In the peripheral nervous system, saltatory conduction is made possible by a series of morphologically and molecularly distinct subdomains in both axons and their associated myelinating Schwann cells.

Why is saltatory conduction along a myelinated axons?

Why is saltatory conduction along a myelinated axon faster than continuous conduction along an unmyelinated axon? The lack of myelin around unmyelinated axons causes them to be unable to conduct impulses; therefore the myelinated axons will have a faster impulse conduction rate.

Why is conduction velocity faster in myelinated axons?

By acting as an electrical insulator, myelin greatly speeds up action potential conduction (Figure 3.14). For example, whereas unmyelinated axon conduction velocities range from about 0.5 to 10 m/s, myelinated axons can conduct at velocities up to 150 m/s.

Why is sodium positively charged?

A sodium atom can lose its outer electron. It will still have 11 positive protons but only 10 negative electrons. So, the overall charge is +1. A positive sign is added to the symbol for sodium, Na +.

What causes the inside of a membrane to become positively charged during an action potential?

Action potentials are caused when different ions cross the neuron membrane. A stimulus first causes sodium channels to open. Because there are many more sodium ions on the outside, and the inside of the neuron is negative relative to the outside, sodium ions rush into the neuron.

Why do myelinated axons conduct impulses faster than unmyelinated axons?

Summary. Myelin can greatly increase the speed of electrical impulses in neurons because it insulates the axon and assembles voltage-gated sodium channel clusters at discrete nodes along its length.

Why myelinated axons conduct signals faster than Unmyelinated axons?

Unlike unmyelinated axons, myelinated axons are surrounded by an insulatory myelin sheath produced by Schwann cells. Because of this insulatory sheath, action potentials cannot occur along the entire length of a myelinated axon but only at the gaps between Schwann cells, known as Nodes of Ranviers.

What happens at peak of action potential?

At the peak of the action potential, two processes occur simultaneously. First, many of the voltage-gated sodium channels begin to close. Second, many more potassium channels open, allowing positive charges to leave the cell.

Where does the first action potential occur in a myelinated axon?

As in un-myelinated axons, the first action potential in myelinated axons takes place at the initial segment of an axon and is generated by a threshold stimulus from the dendrites and cell body.

What is saltatory conduction in axons?

Saltatory Conduction. As in un-myelinated axons, the first action potential in myelinated axons takes place at the initial segment of an axon and is generated by a threshold stimulus from the dendrites and cell body.

What is the function of myelin in axon conduction?

Myelin facilitates conduction Myelin is an electrical insulator; however, its function of facilitating conduction in axons has no exact analogy in electrical circuitry.

How does myelin speed up the transmission of electrical impulses?

More precisely, myelin speeds the transmission of electrical impulses called action potentials along myelinated axons by insulating the axon and reducing axonal membrane capacitance.