Circulation

Label the different chamber, valves no blood vessels on the diagram of the heart

a

b

c

d

e

f

g

h

i

Pulmonary artery

Vena cava

Septum

Right ventricle

Pulmonary vein

Left Atrium

Right atrium

Atrioventricular valve

Semilunar valve

______ prevent the back flow of blood

Deoxygenated blood returns to the heart via the ____ ____.

Match the following blood vessels

• Vein

• 
• Artery

• 
• Capillary

• 

Match the following blood vessels with their function

• Vein

• Think walled, with elastic and smooth muscle to allow it to withstand high pressure

• Capillary

• Thin walled to allow exchange of substances

• Artery

• Thin walled, but contains valves to prevent backflow of blood

As arteries get further from the heart, they branch into smaller vessels called arterioles. Why do these have increasing amounts of smooth muscle?