The Cardiovascular System

Question 1

Order in which blood flows through heart

Answer 1

Vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta, body

Question 2

Which side of the heart is thicker and why?

Answer 2

the left because it has to pump blood to the entire body so it has to work against a much higher pressure

Question 3

What is the function of the arteries?

Answer 3

To carry oxygenated blood away from the heart

Question 4

What is the function of the veins?

Answer 4

Carry oxygenated blood back to the heart

Question 5

What is the function of the atrioventricular valves?

Answer 5

To prevent the back flow of blood from the ventricles to the atria.

Question 6

Why is the left ventricle thicker than the right?

Answer 6

The left ventricle needs to contract harder to pump more blood further around the body and therefore requires more muscle (Right only pumps blood to lungs).

Question 7

What is the function of the heart cords?

Answer 7

To prevent atrioventricular valves from turning inside out and to ensure the unidirectional flow of blood.

Question 8

What is the function of the semi lunar valves?

Answer 8

To prevent the back flow of blood that has been pumped out of the heart from going into the ventricles

Question 9

Describe the structure of arteries

Answer 9

Narrow lumen to maintain high blood pressure, thick layer of smooth muscle (contract and relax to dilate and constrict blood vessels - controlling their diameter) with elastic fibres (stretch and recoil), smooth inner endothelial lining, lots of collagen fibres.

Question 10

Describe the structure of veins

Answer 10

Large lumen to minimise resistance to flow, thinner layer of muscle and elastic fibres, reduced collagen fibres, valves to prevent back flow of blood.

Question 11

Describe the structure of capillaries

Answer 11

Very small, narrow lumen, thin endothelial tissue (one cell thick to maintain a short diffusion distance between cells).

Question 12

What are the vessels entering the heart?

Answer 12

superior/inferior vena cava, pulmonary veins

Question 13

What are the vessels leaving the heart?

Answer 13

Aorta, pulmonary artery

Question 14

What is the vessel entering the lungs?

Answer 14

Pulmonary artery

Question 15

What is the vessel that leaves the lung?

Answer 15

Pulmonary vein

Question 16

What is the function of the goblet cells?

Answer 16

Secretes mucus that traps foreign particles.

Question 17

What is the function of the ciliated epithelial cells?

Answer 17

to move substances along surface of tissue

Question 18

Cystic fibrosis

Answer 18

A genetic disorder that is present at birth, caused by a recessive allele that causes a faulty CTFR channel in the cell membranes. This gene that is faulty codes for the production of chloride ion channels (leads to them being non functional).

Question 19

Symptoms of cystic fibrosis

Answer 19

• thick mucus build up in the lungs
• Wheeziness of breathing
• Salty tasting skin
• frequent respiratory infections

Question 20

Problems with cf thicker mucus?

Answer 20

Harder for the cilia to move, bacteria thrive in mucus (lots of infections), stops air getting to alveoli which causes shortness of breath.

Question 21

Cardiac cycle: atrial systole

Answer 21

The atria contract forcing the atrioventricular valves open and blood flows into the ventricles.

Question 22

Cardiac cycle: ventricular systole

Answer 22

The ventricles contract which forces the atrioventricular valves shut and the semi lunar valves open, thus allowing blood to leave the left ventricle through the aorta and the right ventricle through the pulmonary artery.

Question 23

Cardiac Cycle: cardiac diastole

Answer 23

The atria and ventricles relax and pressure inside the heart chambers decreases causing semilunar valves in the aorta and pulmonary arteries to close, preventing the back flow of blood.

Question 24

Relate the structure of the atria to their function

Answer 24

They are thin walled and elastic so they can stretch when filled with blood.

Question 25

Relate the structure of the ventricles to their function

Answer 25

They have thick muscular walls to pump blood under high pressure. The left ventricle is thicker than the right as it has to pump blood further (all around) the body.

Question 26

Vena cava function

Answer 26

Brings deoxygenated blood from the body to the heart.

Question 27

pulmonary artery function

Answer 27

Takes blood away from the heart to the lungs

Question 28

Stroke volume

Answer 28

the volume of blood pumped out by a ventricle with each heartbeat