7.2 - Overview of the circulatory system

Question 1

What is the pulmonary circulatory system?

Answer 1

1. Deoxygenated blood is pumped out of the heart via the pulmonary artery to the lungs.
2. Oxygenated blood is returned to the heart via the pulmonary vein from the lungs.

Question 2

What is the systemic circulatory system?

Answer 2

1. Oxygenated blood is pumped out of the heart via the aorta to most body tissues.
2. Other blood vessels branch from the aorta to deliver blood to body tissues (e.g. the renal artery delivers blood to the kidneys).
3. Veins collect deoxygenated blood from these organs (e.g. the renal vein collects deoxygenated blood from the kidneys).
4. Deoxygenated blood is returned to the heart via the vena cava.

Question 3

Our circulatory system

Answer 3

Question 4

What is a closed, double circulatory system?

Answer 4

• It is a closed system- Blood is contained in blood vessels.
• It is a double system- Blood passes through heart twice per circuit.

Question 5

why do multicellular organisms need internal transport systems?

Answer 5

• Multicellular organisms are larger, so the diffusion distance across their surface would be too large.
• Multicellular organisms have a higher metabolic rate.
• Multicellular organisms need to supply nutrients and oxygen rapidly to a larger number of active cells.

So overall, diffusion alone would be too slow