The heart and blood vessels

Question 1

What is the function of pacemakers

Answer 1

Pacemakers control the speed and regularity of the heart beat by regulating contractions of the heart

Question 2

Describe how deoxygenated blood travels through the heart

Answer 2

1. Deoxygenated blood travels to the right atrium via the vena cava
2. The right atrium contracts and pushes the blood down to the right ventricle
3. the right ventricle contracts and pushes the blood to the lungs (via the pulmonary artery) to be oxygenated

Question 3

Where are pacemaker cells found?

Answer 3

In the right atrium

Question 4

What are stents

Answer 4

Stents are expandable tubes that are placed inside the coronary arteries to expand the lumen, thus increasing the blood flow o the heart in the case of coronary heart disease

Question 5

What is Coronary Heart Disease?

Answer 5

1. The lumen in the coronary arteries become narrow due to a build up of fatty material
2. This reduces the amount of blood flow to the heart.
3. Therefore, less glucose and oxygen reach the heart
4. This means that there is less respiration
5. Leading to less energy for the heart muscles to contract
   So heart cells may die and a heart attack may happen

Question 6

What are the implications of coronary heart disease

Answer 6

As less blood is flowing through the coronary arteries, less oxygen is being supplied to the heart muscle and so the heart cells cannot respire.

This can cause the cells in the heart to eventually die.

Question 7

Name some benefits of using stents for coronary heart disease

Answer 7

Surgery is relatively quick and low risk

They last for a long time

Question 8

Name some disadvantages of using stents for coronary heart disease

Answer 8

They require surgery which has risks, a heart attack during surgery or an infecction

They can potentailly lead to blood clots near the stent (thombrosis)

Fatty deposits can build up again

Question 9

What do statins do?

Answer 9

Statins are drugs that reduce blood cholesterol levels.

This reduces the rate of fatty material deposit; this can help in the case of coronary heart disease

(but also strokes and heart attacks)

Question 10

Name some disadvantages of statins

Answer 10

The drugs need to be taken regularly and some people may forget, this can increase the risk of them getting coronary heart disease

The drugs have side affects: head aches, kidney failure

Question 11

What is the function of the heart valves

Answer 11

The valves open and close so that blood travels in one direction

Question 12

Name ways in which heart valves can become faulty

Answer 12

The valves can become stiff and so they won’t open fully
or
The valve doesn’t close properly so blood can leak backwards

Question 13

What are the consequences of a faulty valve?

Answer 13

less blood will reach the body
and
lungs can swell up with fluid

Question 14

How are faulty valves fixed?

Answer 14

They are replaced with either a new biological or mechanical valve

Question 15

What are biological valves?

Answer 15

Valves made of tissues or valves derived from human or animal donors such as pigs or cows

Question 16

What are mechanical valves

Answer 16

Artificial valves made of carbon and metal

Question 17

Name some advantages of biological valves

Answer 17

Lower risk of blood clots forming as they don’t damage red blood cells

Question 18

Name some disadvantages of biological valves

Answer 18

1. Surgery is required which has risks such as infection and heart attack during surgery
2. Don’t last very long as they can hardenand need to be replaced after a few years
3. Can be rejected by the patient’s body
4. Some religions may be agaisnt the use of animals such as pigs and cows as donors

Question 19

Name some advantages of mechanical valves

Answer 19

They last long

They will not be rejected by the body

Question 20

Name some disadvantages of mechanical valves

Answer 20

1. Surgery is required, which has risks such as infection and heart attack
2. Can damage red blood cells so blood clots can form around the valve and so anticlotting drugs need to be taken regularly
3. If a patient forgets to take anticlotting drugs, there can be some serious health risks

Question 21

What is done to treat heart failure?

Answer 21

A heart transplant of either a biological or artificial heart

Question 22

What is heart failure?

Answer 22

When the heart cannot pump blood around the body anymore

Question 23

What are the disadvantages of an artificial heart?

Answer 23

They can only be used temporarily while a patient is waiing for a biological heart donor

Question 24

Describe how oxygentated blood travels through the heart

Answer 24

1. The oxygenated blood from the lungs enters the left atrium via the pulmonary vein
2. The left atrium contracts and pushes the blood down to the left ventricle
3. Then the left ventricle contracts and pushes the blood up to the aorta where blood is pumped away from the heart to the **body

Question 25

Where are hearts for a **biological transplant** from?

Answer 25

From another human

Question 26

What are the **disadvantages** of using a **biological** heart transplant

Answer 26

1. It **takes a long time** to find a **suitable donor** 2. When a donor is found, the heart may be **rejected** by the patient's body's immune system, as it may see the heart as **foreign** and try to destroy it 3. It is a **major operation** and may come with many surgical risks like **infection** 4. **Anti-rejection** drugs needed to be taken for life

Question 27

Waht are the **advantages** of a **biological** heart transplant?

Answer 27

1. Patient can **live longer** 2. The patient can enjoy an **improved quality of life** 3. Patient can have **higher energy levels** 4. Can have a **more normal day to day lifestyle**

Question 28

**What type** of **circulatory system** do **humans have**?

Answer 28

**Double circulatory system**