Circulation

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

a

b

c

d

e

f

g

h

i

Semilunar valve

Right atrium

Pulmonary vein

Pulmonary artery

Septum

Vena cava

Atrioventricular valve

Left Atrium

Right ventricle

______ prevent the back flow of blood

Deoxygenated blood returns to the heart via the ____ ____.

Match the following blood vessels

• Capillary

• 
• Artery

• 
• Vein

• 

Match the following blood vessels with their function

• Vein

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

• Capillary

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

• Artery

• Thin walled to allow exchange of substances

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