Fast axonal transport is important for synapses because proteins are synthesized in the cell body and are transported down the axon by anterograde to the synaptic terminal. The proteins at the synaptic terminal which have reached the end of their lifetime are then transported back to the cell body by the retrograde transport for degradation and recycling.
2. Can depolarization occur without an action potential being created? Explain
An action potential begins when a depolarization increases the membrane voltage so that it crosses a threshold value. 3. If a strong stimuli (suprathreshold) is applied, how is it reflected when we observed an action potential?
It can increase the frequency of action …show more content…
Which ion causes hyperpolarization and how does it happen?
K+ cause hyperpolarization. K+ channels remain open and it happens when K+ ions are rushed into the cell to repolarize the membrane. Then the repolarization goes passing through the resting potential of the membrane and hyperpolarizes. Basically in other words hyperpolarization assures that the signal is only going in one direction.
7. Describe briefly your understanding of how propagation/conduction occurs in an unmyelinated axon.
I understand that the myelination causes all the channels to compacted in the nodes of Ranvier making an action potential appear to "jump" from node to node. Now, in both unmyelinated and myelinated cells, Na/K ATPases are present along with Na+ and K+ channels, along the length of axon. If a cell is unmyelinated, it can pump Na+ back out into the ECF, causing a loss of conduction and decreasing the frequency of axon potentials. In myelinated cells, however, the myelin blocks these pumps from pumping Na+ out of the cell, and maintains concentrations. If Na/K ATPases are only able to pump Na+ ions out at the nodes of Ranvier, leakage will only occur there.
8. List the types of synapses
• Electrical- Very