The Cardiovascular System

Question 1

What is the circulatory system? (2)

Answer 1

1. The collection of organs and tissues that ensures oxygenated blood is pumped to locations where it is needed within the body.
2. Also transports waste products like CO2 and urea to where they can be removed

Question 2

Why is the human circulatory system called a double circulatory system? (2)

Answer 2

1. Blood enters and leaves in two loops

2. Blood is either oxygenated or deoxygenated in each loop.

Question 3

What are the advantages of a double circulatory system? (2)

Answer 3

1. Pumps blood at a higher pressure, which gets oxygen around the body quicker
2. Requires heart chambers in order to separate the blood, which is more efficient.

Question 4

Describe the process of blood transport within the body. (6)

Answer 4

1. Deoxygenated blood enters the heart through the vena cava (vein).
2. It is then pumped into the right atrium, before passing into the right ventricle through the right atrio-ventricular valves (tricuspid)
3. From the right ventricle, the blood is pumped into the pulmonary artery through the semi-lunar valves.
4. The oxygen-poor blood is passed through the lungs where it “picks up” oxygen before coming back into the heart through the pulmonary vein.
5. The now oxygen-rich blood enters the left atrium before entering the thicker left ventricle through the left atrioventricular valves (bicuspid)
6. The blood is passed through the semilunar valves into the aorta (artery), where it is pumped throughout the whole body.

Question 5

Why do humans have specialised blood cells?

Answer 5

Maintains efficiency which saves energy to use in other vital processes.

Question 6

Name the different components of blood.

Answer 6

1. Red blood cells
2. White blood cells
3. Plasma
4. Platelets

Question 7

Give the features of red blood cells. (3)

Answer 7

1. Carries oxygen by binding to hemoglobin.
2. Biconcave shape (thin center) with no nucleus, which maximises surface area for oxygen absorption and increases amount of hemoglobin
3. Linked to anaemia.

Question 8

Give the features of white blood cells. (3)

Answer 8

1. Responsible for phagocytosis (engulfing pathogens) or producing antibodies.
2. Irregular shaped with nucleus and lots of ribosomes to synthesis proteins for immune function.
3. Linked to AIDS

Question 9

Give the features of platelets.

Answer 9

1. Become adhesive and stick together to form clots
2. Are cellular fragments of red blood cells.
3. Linked to hemophilia.

Question 10

Give the features of plasma. (2)

Answer 10

1. Yellow liquid contains and carries small soluble substances, proteins, nutrients blood cells and urea.
2. Linked to dehydration.