Valves

Question 1

What causes valves to open and close

Answer 1

Pressure

Question 2

Job of the valves

Answer 2

Prevent back flow

Question 3

Name the 3 valves

Answer 3

• atrioventricular valves
• semi-luna valves
• pocket valves

Question 4

Describe atrioventricular valves

Answer 4

• located between atria and ventricles
• prevent back-flow to atria when ventricles contract
• close when pressure higher in ventricles that article
• ensures blood moves to aorta and PA

Question 5

Describe semi-Luna valves

Answer 5

• located in aorta and PA
• Prevent back-flow into ventricles
• close when pressure higher in arteries than in ventricles

Question 6

Describe pocket valves

Answer 6

• located throughout veins
• prevent back flow when veins squeezed and pressure increased eg muscles contracting
• ensure blood flows back to heart

Question 7

Equation for cardiac output

Answer 7

Heart rate x stroke volume