Circulatory System

Question 1

Systole

Answer 1

contraction of the cardiac muscle; the pumping phase

Question 2

Diastole

Answer 2

relaxation of the cardiac muscle; the filling phase

Question 3

Arteries

Answer 3

carry blood away from the heart. have walls of elastic, smooth muscle. vasodilation and vasoconstriction can increase or reduce blood flow to an organ. small arteries = arterioles. blood pressure in the arteries is variable.

Question 4

Veins

Answer 4

carry blood towards the heart. do not have muscular, elastic walls, and are much thinner than those of arteries. contain valves to prevent backflow. constant, relatively low blood pressure.