Answer:
I, II, III
Explanation:
A threshold stimulus is a stimulus that is capable to produce a response in excitable tissues such as neurons and muscle fibers. At threshold potential, the outward movement of K+ and inward movement of Na+ become equal to each other. When the potential exceeds the threshold potential, more and more Na+ enter the cell to depolarize it and to allow the opening of Na+ channels. Therefore, to fire an action potential, the threshold must be exceeded.
Conduction of action potential is all or none phenomenon which means that either it occurs or it does not occur. As an impulse is passed by each successive part of an exon, it enters the refractory period during which there is no conduction of nerve impulse. It ensures the one-way conduction of impulse from the cell body to the axon terminal only.
When a cell has too much of one thing, homeostasis gets rid of some of it and balances the cell out. Just like when you have too much stress, you find ways (coping mechanisms) to get rid of some of it.
Explanation:
Hope this helps!
Construction contributes to soil erosion because;
C. It removes vegetation from the building site.
Answer:
SV = 30 ml/ beat.
HR = 80.
Explanation:
The formula to calculate SV is as follows:
SV = EDV- ESV.
Here EDV = 90ml (end diastolic volume), ESV = 60ml (end systolic volume) ans SV is stroke volume.
SV = 90-60
SV = 30ml/beat.
The formula to calculate HR is as follows:
HR = CO/SV
Here, HR is heart rate, CO is cardiac output = 2,400 ml/min and SV is stroke volume = 30ml/beat
HR = 2,400/30
HR = 80.
Thus, the SV is 30ml/best and HR is 80.
Though all choices protect your organs the most important would be your bones.
