circulation

Question 1

state the 4 components of blood

Answer 1

plasma - carries substances and body cells in the blood e.g urea, carbon dioxide, white blood cells.
platelets - fragments of RBCs that clot the blood.
red blood cells - contains haemoglobin and binds to oxygen which helps carry oxygen from lungs to the rest of the body.
white blood cells - protect body from infection, engulf pathogens.

Question 2

describe the feature of the mammalian circulatory system.

Answer 2

high pressure pumping through arteries - helps carry blood all around the body.
slow travel of blood through capillaries - more diffusion of substances and molecules into cells.
valves in veins - prevents back flow of blood.
blood pressure gradient (high in arteries to low in veins) - so blood flows in one direction (unidirectional blood flow)

Question 3

what type of blood vessel transports blood towards the liver?

Answer 3

hepatic

Question 4

what type of blood vessel transports blood towards the kidney?

Answer 4

renal

Question 5

what type of blood cell transports blood towards the heart?

Answer 5

coronary

Question 6

describe the general pattern of blood circulation in a mammal.

Answer 6

closed double circulatory system - blood passes through the heart twice for every circuit around the body:
- deoxygenated blood in the right side of heart pumped to lungs, oxygenated returns to left side.
- oxygenated blood in left side of heart pumped to rest of body, deoxygenated returns to right.

Question 7

suggest the importance of a double circulatory system.

Answer 7

• prevents mixing of oxygenated/deoxygenated blood (so blood pumped to body is fully saturated with oxygen for aerobic respiration)
• blood can be pumped at a higher pressure so substances are taken to/removed from body cells quicker.

Question 8

which vessel transports oxygenated blood from heart to body tissues?

Answer 8

aorta

Question 9

which vessel transports deoxygenated blood from the heart to the lungs?

Answer 9

pulmonary artery - deoxygenated blood is oxygenated and carbon dioxide is removed.

Question 10

which vessel oxygenated blood from the lungs to the heart?

Answer 10

pulmonary vein

Question 11

which vessel transports deoxygenated blood from body tissues to the heart?

Answer 11

vena cava

Question 12

name the blood vessels entering and leaving the kidneys.

Answer 12

renal arteries - oxygenated blood to the kidneys.
renal veins - deoxygenated blood to vena cava from the kidneys.

Question 13

suggest why the wall of the left ventricle is thicker than that of the right.

Answer 13

has thicker muscle to contract with greater force, to generate higher pressure to pump blood around the entire body.