The structure of the heart

Question 1

What is the heart?

Answer 1

A muscular organ which in the thoracic cavity behind the breastbone.

Question 2

What does the left and right side of the heart do?

Answer 2

Left - Deals with oxygenated blood from the lungs

Right - Deals with deoxygenated blood from the body

Question 3

What are the 2 chambers of the pump?

A–V (alphabetical order)

Answer 3

• The atrium is a thin walled and elastic and stretches as if collects blood.
• The ventricle has a much thicker muscular wall as it has to contract strongly to pump blood over some distance, either to lungs or rest of the body.

Question 4

Why does the heart have 2 separate pumps?

Answer 4

Because blood has to pass through tiny capillaries in the lungs to present a large SA for gas exchange and by passing through the lungs, there’s a drop in pressure so the blood flow to the rest of the body would be very slow. So mammals need the blood to return to the heart to increase the pressure before it is passed through the body.

Question 5

What does the right ventricle do?

Answer 5

The right ventricle pump blood TO the lungs, it has a thinner muscular wall than the left.

Question 6

What does the left ventricle do?

Answer 6

The left ventricle has a thick muscular wall, it allows contraction to create enough pressure to pump blood to the rest of the body.

Question 7

What are the 2 types of valves?

Answer 7

Left and right AV valve

Left and right SL valve

Question 8

What does AV valve do?

Answer 8

Link the atrium to the ventricles and stop blood flowing back into the atrium when the ventricles contract.
Atrium to the ventricle, therefore, AV valve.

Question 9

What does SL valve do?

Answer 9

Link the ventricles to the pulmonary artery on the right or pulmonary vein to the aorta on the left to stop blood flowing back into the heart after the ventricles contract.

Question 10

What are cords?

Answer 10

The cords attach the AV to the ventricles to stop them from being forced up into the atrium when ventricles contract.

Question 11

How does blood flow between the heart and lungs?

Answer 11

VAVA VAVA 
Vena Cava
Right atrium
Right ventricle
Pulmonary artery

Pulmonary veins
Left atrium
Left ventricle
Aorta

Question 12

How are blood pumped in and out of the heart?

Answer 12

The ventricles pump the blood away from the heart and into the arteries. The atria receive blood from the veins.

Question 13

What is the name of the vessel which connects the heart to lungs?

Answer 13

Pulmonary vessels.

Question 14

What are the 4 chambers which the pulmonary vessels are connected to?

Answer 14

• Aorta - connected to the left ventricle and carries oxygenated blood to the rest of the body.
• Vena Cava - Connected to the right atrium and brings deoxygenated blood back from the tissues of the body.
• Pulmonary artery - connected to the right ventricle and carries deoxygenated blood to the lungs, where O2 is restored and CO2 is removed.
• Pulmonary vein - connected to the left atrium and brings oxygenated blood back from the lungs.

Question 15

How does heart get its oxygen supply?

Answer 15

Heart muscles do not get its oxygen supply from the oxygenated blood which is passed from the left side of the heart.
It is supplied by its own blood vessels, the coronary arteries which branch off the from the aorta.
It also provides glucose.

Question 16

What harm would it cause if the coronary arteries are blocked?

Answer 16

Blockage to those arteries e.g. blood clot leads to a heart attack because of the area of the heart muscle doesn’t have blood and therefore no oxygen. The muscle cells in this region, therefore, cannot respire aerobically and so it dies.

Question 17

How can smoking be a risk factor for cardiovascular disease?

Answer 17

Carbon monoxide combines easily and it’s irreversible once it’s combined with the haemoglobin to form carboxyhaemoglobin which reduces the oxygen-carrying capacity so for the same amount of supply of oxygen to be, the heart has to work harder so there’s an increase of blood pressure and increase the risk of coronary heart disease.