Question

In: Anatomy and Physiology

Why does the action potential spread in only one direction (toward the axon terminal)?

Explain how an action potential when fired spreads to the rest of the axon.

Why does the action potential spread in only one direction (toward the axon terminal)?

Explain why action potentials are conducted more quickly and effectively (in terms of energy used) in myelinated cells than in unmyelinated cells.


Solutions

Expert Solution

Action potential travels from cell body to axon of a neuron when there is a change in polarity of axonal membrane which occurs due to mechanism of sodium and potassium pump.

The action potential always remains unidirectional from cell body to axon but never reversed, it occurs due to refractory period of sodium channel. During refractory period sodium channels of becomes inactivate after reaching to threshold impulse and passes to forward.

In myelinated nerve fibres action potential or impulse travels via saltatory mechanism in which impulse jumps from one node (Ranvier's node) to another and prevent from energy loss during conduction at remaining axon. Hence, nervous conduction also become more quick in them.


Related Solutions

How does an action potential move in only one direction down an axon? discuss the three...
How does an action potential move in only one direction down an axon? discuss the three conformations or voltage gated sodium channels in the answer.
Describe the events that take place when the action potential spreads throughout the axon terminal leading...
Describe the events that take place when the action potential spreads throughout the axon terminal leading up to the release of neurotransmitters into the synaptic cleft.
Which of the following statements is INCORRECT regarding action potentials? A. The axon terminal of a...
Which of the following statements is INCORRECT regarding action potentials? A. The axon terminal of a neuron can send only one type of NT to the dendrites of its postsynaptic neighbor. B. AP signals can be summed spatially, but cannot be summed temporally because they are all-or-nothing events. C. Post-synaptic neurons can receive information from many different neurons via their NT receptors. D. If an NT causes the postsynaptic cell’s membrane to become hyperpolarized, this reduces the likelihood that it...
There are two properties that affect the conduction speed of an action potential along an axon
There are two properties that affect the conduction speed of an action potential along an axon: the axon's diameter and whether or not the axon is myelinated. Rank the axons from slowest to fastest conduction speed. If two axons have the same conduction speed, place one on top of the other.
When one action potential is traveling along an unmyelinated axon from cell body side and another...
When one action potential is traveling along an unmyelinated axon from cell body side and another action potential is traveling along the axon from synaptic terminal side, these two action potentials are going to collide with each other at the center of the axon. What is going to happen to these action potentials after the collision?
Does diffusion occur in only one direction, or can one substance diffuse in one direction, and...
Does diffusion occur in only one direction, or can one substance diffuse in one direction, and a second substance diffuse in the opposite direction? What is your evidence? Give specific examples. What determines the direction of diffusion?
Describe how an action potential is propagated through an axon, and how neurotransmitters are released in...
Describe how an action potential is propagated through an axon, and how neurotransmitters are released in response to the action potential reaching the synaptic terminal
why does na+ enter the cell during action potential?
why does na+ enter the cell during action potential?
Describe how an action potential is generated across the axon. Make sure to explain the role...
Describe how an action potential is generated across the axon. Make sure to explain the role of Na+ and K+ channels and pump in this process.
Describe how an action potential propagates along a myelinated and an unmyelinated axon, including how the...
Describe how an action potential propagates along a myelinated and an unmyelinated axon, including how the potential is spread along the membrane. How are these two processes similar and how are they different? What two benefits do myelinated axons have over unmyelinated ones? Provide one way in which a myelinated axon is similar to an electrical wire and one way in which an axon is different than a wire. Why does multiple sclerosis (MS) prevent transmission in myelinated axons (that...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT