WorksheetsAction potential generation and propagation
Total questions: 21
Worksheet time: 13mins
Why is -55 mV a significant number?
This is the largest charge achieved during an action potential
This is the threshold required to generate an action potential
This is the resting charge of a neuron
This is the charge when all the sodium is inside the cell
At what stage does Potassium move outside the neuron, and Sodium stop moving inside the neuron?
Depolarizarion
Repolarization
Hyperpolarization
Resting Potential
What number(s) on the graph represents the THRESHOLD level of stimulus?
1 and 5
2
3
6
Which one of the following is involved in maintaining a resting membrane potential?
Na+/K+ ATPase pump moves 3Na+ in for every 2K+ out
Na+/K+ ATPase pump moves 3K+ in for every 2Na+ out
Na+/K+ ATPase pump moves 3Na+ out for every 2K+ in
Na+/K+ ATPase pump moves 3K+ out for every 2Na+ in
The speed of the electrical impulse through the axon, is influenced by the myelin sheath and
soma cells
Schwaan cells
Nodes of Ranvier
axon terminals
dendrites
Neurons transmit information through ________ changes in the cell membrane.
chemical
electrical
Select the ion channels that increase the membrane potential enough to generate a graded potential (between -70mV and -55mV)
Voltage gated channels
Leak channels
Ligand gated channels
Mechanical gated channels
Once the membrane potential reaches -55mV, what occurs
Sodium voltage gated channels open and a graded potential is generated
Sodium voltage gated channels close and a graded potential is generated
Sodium voltage gated channels open and a action potential is generated
Sodium voltage gated channels close and a action potential is generated
A action potential is generated at the
Dendrites
Axon hillock
Cell body
Axon
Saltatory propagation is faster than continuous propagation because:
Each Node of Ranvier has voltage gated ion channels to rapidly depolarise the axon
The current jumps from one Node of Ranvier to the next
Depolarisation only occurs at the Node of Ranvier
All of the above
Action potentials are propagated as the positive current rapidly flows through the axon, insulated with myelin sheath. At each Node of Ranvier, sodium voltage gated channels open and more sodium floods in. This intensifies the flow of positive ions and ensures it will move in one direction
True
False
