The circulatory system and blood

Question 1

What is the definition of the circulatory system?

Answer 1

A system made up of blood vessels that carry blood away from and towards the heart

Question 2

What is the definition of arteries?

Answer 2

Blood vessels that carry blood away from the heart

Question 3

What is the definition of arterioles?

Answer 3

very small arteries delivering blood to capillaries

Question 4

What is the definition of veins?

Answer 4

Blood vessels that carry blood back to the heart

Question 5

What is the definition of venules?

Answer 5

very small veins collecting blood from capillaries

Question 6

What is the definition of capillaries?

Answer 6

Connect arteries to veins

Question 7

What is the definition of blood?

Answer 7

The fluid that moves through the circulatory system

Question 8

What is in the blood (4)

Answer 8

1. Plasma - mostly water 55%
2. Red blood cells (erythrocytes) - contain a protein called haemoglobin that carries oxygen 44%
3. White blood cells (leukocytes) - important in immune response <1%
4. Platelets (thrombocytes) - important for blood clotting <1%

Question 9

What are the parts of the circulatory system? (3)

Answer 9

1. Heart
2. Blood vessels (arteries, veins, capillaries)
3. Blood

Question 10

What are the circuits of the circulatory system (3)

Answer 10

1. Pulmonary circuit: pulmonary arteries carry deoxygenated blood away from the heart to the lungs, pulmonary veins return oxygenated blood to the heart
2. Systemic circuit: arteries carry oxygenated blood away from the heart to the rest of the body, veins pick up waste products and return deoxygenated blood to the heart
3. Coronary circuit: coronary arteries carry oxygenated blood to the heart, veins pick up waste products and return deoxygenated blood to the heart

Question 11

How does blood circulate throughout the body from the atria? (8)

Answer 11

1. Atria
2. Ventricles
3. Arteries
4. Arterioles
5. Capillaries/organs
6. Venules
7. Veins
8. Atria

Question 12

What is the function of capillaries?

Answer 12

Capillaries are trading stations where oxygen and nutrients contained within the blood are exchanged with waste from organs/tissues.

Question 13

How are circulations to organs described (2)

Answer 13

1. parallel (except for gastrointestinal and hepatic circulations, which are partly in series)
2. This enables efficient and continuous blood flow in a closed cycle.
3. If the blood supply to one organ is compromised, the blood supply to another is not impacted.