Question

can you please help me answer these 3 questions

1. Can a threshold stimulus reaching the axon hillock during an ongoing action potential produce another action potential? Explain based on the property of ion channels involved?
2. What could be the consequence of blocking all voltage-gated calcium channels on a neuron?
3. Explain the role of motor units in determining strength versus fine control of responses of various muscles?

Answer 1

1. Action potential is a rapid depolarisation and a slight reversal of a normal membrane potential. Action potential take place when deplarisation meet or goes beyond the thresold of excitation. The action potential begins at axon hillock. The action potential is regenerated due to sodium ion moving down the axon, depolarising adjacent areas of neurons

2. Voltage gated ion channels are part of transmembrane protiens, that gets activated due to change in membrane potential, in both side of cell membrane. Calcioum ions plays an important role in release of neurotransmitters.

If these channels blocked, release of neurotransmitter will be inhibited.

3. A motor unit is a motor neurone, and all of the muscle cells it activated. The strength of muscle contraction is determined by the size of motor unit.