The Heart and blood vessels 4.2.2.2

Question 1

What do arteries do and features?

Answer 1

• Carry blood away from the heart

- Thick muscular and elastic wall(blood is under higher pressure than in veins)

Question 2

What do veins do and features?

Answer 2

• Transport blood to the heart
• Large Lumen
• Valves prevent blood flowing backwards
• Lower pressure(than arteries)

Question 3

What do capillaries do and features?

Answer 3

• Single cell thick – short diffusion distance for

- Permeable – substances can be exchanged with tissues

Question 4

What is the equation for flow rate/rate of blood flow?

Answer 4

rate of blood = volume of blood/number of minutes

Question 5

What are the advantages of a double circulation system like the heart?

Answer 5

• Higher pressure

- Greater rate of flow to the tissue

Question 6

Describe the process when blood enters and leaves the heart(right side)

Answer 6

deoxygenated blood comes from the body and enters the heart via the vena cava to the right atrium. Then the blood is pumped through a set of valves to the right ventricle. The blood is pumped again through another set of valves to the lungs via the pulmonary arties.

Question 7

Describe the process which blood enters and leaves the heart(left side)

Answer 7

oxygenated blood from the lungs enters the heart via the pulmonary vein to the left atrium. The blood is then pumped through a set of valves to the left ventricle. Then the blood is pumped again through another set of valves through the aorta then to the rest of the body

Question 8

What is a pacemaker and where is it located

Answer 8

• cells produce an electrical impulse that spreads to surrounding muscle, causing it to contract
• located in the right atrium