HISTOLOGY
NERVOUS TISSUE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Yes
|
|
|
No
|
|
|
Either A or B
|
|
|
None of the above
|
Detailed explanation-1: -Presence of Myelin In an unmyelinated axon, the action potential moves in a continuous wave. In additional to the saltatory conduction process, the presence of myelin also insulates the axon, preventing charge loss across the membrane, which also increases speed of the action potential.
Detailed explanation-2: -Second, the action potential can only travel in one direction – from the cell body towards the axon terminal – because a patch of membrane that has just undergone one action potential is in a “refractory period” and cannot undergo another.
Detailed explanation-3: -Myelin insulates the axon to prevent leakage of the current as it travels down the axon. Nodes of Ranvier are gaps in the myelin along the axons; they contain sodium and potassium ion channels, allowing the action potential to travel quickly down the axon by jumping from one node to the next.