Why do red bloods cells need to “squeeze” through capillaries?What is the function of precapillary sphincters?

The Blood Vessels 

Circulation and the Blood Vessels
13.4 General Information about Blood Vessels
Objective -c13bob02 – List the order of the following blood vessels and state their function: (1)

⦁ Use the terms to complete the following:
away, capillaries, capillaries, exchange, oxygen-rich, towards, valves, veins,

⦁ Arteries – elastic vessels that carry blood from the heart.

⦁ Why do red bloods cells need to “squeeze” through capillaries?

⦁ What is the function of precapillary sphincters?

13.5 Physiology of Circulation
Objective – Define pulse, blood pressure, systolic pressure and diastolic pressure. (1) Define normal blood pressure, hypertension and hypotension. (1)