Circulatory System

Question 1

Name organ X

Answer 1

Lungs

Question 2

Explain how the heart causes blood to move to organ X

Answer 2

• Blood flows into right atrium
• into right ventricle
• ventricle contracts
• blood pressure increased by heart
• blood moves into pulmonary artery

Question 3

Vessels W and Y

Answer 3

Vena Cava / Aorta

Question 4

Describe how blood in vessel W (Vena Cava) is different from blood in vessel Y (Aorta).

Answer 4

• Blood in Vena Cava is deoxygenated

- Blood in Vena Cava is darker red

Question 5

Explain why wall of left ventricle is is thicker than wall of right ventricle. (2)

Answer 5

• Wall of left ventricle is more muscular because it has to withstand greater pressure of blood compared to right ventricle
• Because left ventricle has to pump blood to whole body unlike right which only pumps to lungs

Question 6

compare heart rate of fit person to heart rate of the unfit person

Answer 6

• Unfit persons heart rate is faster
• both react the same way eg both peak at 10 mins
• heart rate increases more quickly
• heart rate decreases more slowly than fit person

Question 7

Explain why recovery period for the fit person was different from the recovery period for the unfit person.

Answer 7

• fit person recovers faster than unfit person
• the fit person has a greater blood flow/cardiac output
• lactic acid does not build up for fit person because they do not undergo anaerobic respiration

Question 8

Direction that blood flows towards, through and from the heart

Answer 8

D

pulmonary vein —> atrium —> ventricle —> aorta

PAVA

Question 9

Name the part of the blood that transports most of the carbon dioxide to the lungs.

Answer 9

Plasma

Question 10

Explain why it is important that cardiac output of athlete increases during exercise

Answer 10

• the muscles are working harder
• so they need more energy
• aerobic respiration needs to occur for more energy and more glucose
• and so carbon dioxide is removed faster

Question 11

Describe how the circulatory system transports substances around the body.

Answer 11

• Aorta transport blood away from heart
• Vena Cava transport blood to the heart
• Capillaries exchange substances
• substances are carried in the plasma

Question 12

Suggest the effects HCM may have on an athlete during competitive sport

Answer 12

• less blood as it is not going around the body
• less oxygen to the body
• build up of lactic acid causing muscle fatigues

Question 13

Vessel X takes …

Answer 13

B

deoxygenated blood to the lungs

Question 14

Give one reason why the wall of the left ventricle is thicker than the right

Answer 14

• to pump blood around the whole body

Question 15

Describe what would happen to the flow of blood in the left side of the heart if the bicuspid valve didn’t function

Answer 15

• blood would flow backwards from ventricle to the atrium

- less oxygenated blood would be pumped to the body

Question 16

Explain how the structure of this blood vessel is related to its function

Answer 16

• has thick walls and small lumen

- to carry oxygenated blood under high pressure

Question 17

Compare the differences between structure of circulatory system of a fish and the human circulatory system

Answer 17

• Fish heart has 2 chambers, human heart has 4 chambers
• fish heart only has one ventricle and one atrium but human heart has 2 ventricle and 2 atria
• fish only has single circuit circulatory system but human heart has double circulatory system
• only deoxygenated blood flows through fish heart

Question 18

Suggest how blood flowing through pulmonary artery would be different from blood flowing through the aorta

Answer 18

• blood in pulmonary artery is deoxygenated

- blood in pulmonary artery has lower pressure

Question 19

Describe the role of the valve

Answer 19

• prevents back flow of blood

- into atrium

Question 20

Cardiac Output is the volume of blood leaving the …

Answer 20

ventricle every minute

Question 21

Explain the effects that a reduced cardiac output would have on the muscle cells of an athlete

Answer 21

• less blood flow to muscles
• because less blood leaves the heart
• less oxygen and glucose reaching muscles
• reduced rate of aerobic respiration
• less energy released
• less carbon dioxide removed
• greater rate of anaerobic respiration
• reduced muscle contraction

-build up of lactic acid causing fatigue