Mass transport in humans general questions

Question 1

At Q on figure 3 there is a small increase in pressure and in rate of blood flow in the aorta
Explain how this happens and its importance

Answer 1

Elastic recoil
Smooths the blood flow

Question 2

At P on figure 3 the pressure in the left ventricle is increasing. At this time, the rate of blood flow has not yet started to increase in the aorta
Use evidence from figure 3 to explain why

Answer 2

Aortic/semi-lunar valve is closed
Because pressure in aorta is higher than in the ventricle