KINE 2P09: LECTURE THREE PART TWO

Question 1

Graded potentials

Answer 1

For a short time, the opening of ion channels is enabled ions to flow into the cell, eliciting relatively small changes in membrane potential that spread to adjacent regions

Question 2

What are Action potentials and why is it involved with voltage-gated ions

Answer 2

Relativity large and rapid changes in membrane potential
- Voltage-gated ion channels are critical for action potential generation
- Two key voltage-gated ion channels for action potential generation: Na and K channels

Question 3

Absolute refractory period

Answer 3

A second depolarizing stimulus, no matter how strong, will not produce a second action potential

Question 4

Relative refractory period

Answer 4

A period during which a second action potential can be produced only if the depolarizing stimulus is of considerable magnitude.

Question 5

Action potential Propagation

Answer 5

1. Action potential produces local currents of its own that depolarize an adjacent region producing another action potential and so on.
2. action potential only moves in one direction in the direction of the axon terminal

Question 6

Action potentials are propagated along axons faster (greater velocity) in:

Answer 6

1. Larger axons compared to smaller axons
2. Myelinated axons compared to unmyelinated axons

Question 7

In myelinated axons, action potentials occur by ______

Answer 7

saltatory conduction

Question 8

Faster conduction velocity

Answer 8

Less charge leaks out, meaning more charge spreads to adjacent region and next action potential occurs sooner