Cardiovascular Disease

Question 1

What causes atherosclerosis?

Answer 1

Endothelium becomes damaged which leads to an inflammatory response and possible blood clotting. Substances in the blood build up and harden into a plaque that narrows the artery and raises blood pressure.

Question 2

Why does blood need to clot?

Answer 2

prevents blood loss
prevents entry of harmful bacteria
provides a framework for repair

Question 3

Explain the process of blood clotting

Answer 3

A blood clot may form when a blood vessel wall becomes damaged. Cell fragments called platelets stick to the damaged wall of the blood vessel to form a plug. A series of chemical changes occur in the blood. A protein called thromboplastin to be released by the damaged blood vessel and the presence of calcium ions in the blood which triggers the conversion of prothrombin (a soluble protein) into thrombin (an active enzyme). As the thrombin is an enzyme, it is able to catalyse the conversion of fibrinogen into fibrin. The fibres of fibrin then tangle together to form a mesh which traps platelets and red blood cells, forming a blood clot.

Question 4

Describe the formation of atheroma?

Answer 4

• The endothelium lining of the artery is usually smooth and unbroken
• if damage occurs white blood cells and lipids clump to form fatty streaks.
• over time more white blood cells, lipids and connective tissue build up and
  harden to form a fibrous plaque called an atheroma.
• This restricts blood flow and increases blood pressure
• Hardening of arteries is called atherosclerosis

Question 5

Describe the possible effects of a blood clot forming in a coronary artery.

Answer 5

Cells may die due to lack of oxygen and glucose
Results in angina
As heart respires anaerobically
Myocardial infarction

Question 6

Why does smoking increase the risk of CVD?

Answer 6

1. Cigarettes contain carbon monoxide which combines with haemoglobin and reduces the amount of oxygen in the blood, flowing to the tissues which means that there is less oxygen available for respiration which can leads to a myocardial infarction.
2. Smoking also reduces the amount of antioxidants in the blood which increases the likelihood of damage to the artery walls which leads to atheroma formation and then CVD.
3. Nicotine also makes the platelets more sticky which increases the chance of blood clots forming.

Question 7

Explain how high blood pressure increases the risk of developing CVD

Answer 7

High blood pressure can lead to damage to the endothelium of the arteries. This damage causes an inflammatory response which leads to the formation of atheroma (atherosclerosis) which hardens the artery walls and causes an increased risk of blood clots developing (thrombus). This persistent high blood pressure causes a loss of elasticity in the arteries and narrows the lumen. A positive feedback loop is now present so blood pressure will continue to increase.

Question 8

aneurysm

Answer 8

atheromas can damage the artery walls and increase blood pressure. This increased blood pressure can cause the elastic fibres in the artery wall to swell into a balloon-like structure called an aneurysm.

Question 9

Thrombosis

Answer 9

abnormal condition of a blood clot which can cause back flow of blood in the artery.

Question 10

Risk Factor: Diet

Answer 10

A diet high in saturated fat or salts can lead to high levels of LDL cholesterol which contributes to the formations of atheromas in the arteries.

Question 11

Risk factor: smoking

Answer 11

Smoking cigarettes increases the risk of high blood pressure, as carbon monoxide in cigarettes bonds with the haemoglobin in blood which means less oxygen is able to do so. This causes less oxygen to be transported around the body which increases the risk of a heart attack.

Question 12

Risk factor: high blood pressure

Answer 12

can be inherited, from being overweight, causes by excessive alcohol consumption. Contributes to the formation of atheromas.

Question 13

Name 4 ways to treat CVD

Answer 13

Statins, platelet inhibitors, antihypertensives, anticoagulants

Question 14

What do statins do

Answer 14

Statins reduce blood cholesterol (LDL) levels, taken as daily tablet

Question 15

Statin side effects

Answer 15

Mild headaches, nausea etc

Question 16

Anticoagulants function

Answer 16

Lower formation of blood clots which reduces the risk posed by atheromas

Question 17

Anticoagulants side effects

Answer 17

haemorrhage (excessive bleeding), nose bleeds etc

Question 18

Antihypertensives function

Answer 18

to reduce hypertension (high blood pressure) e.g beta blockers

Question 19

Antihypertensives side effects

Answer 19

dizziness, headaches (mild)

Question 20

platelet inhibitors function

Answer 20

work by preventing platelets from sticking together at the site of damage and preventing a blood clot from forming and blocking the artery. Similar to anticoagulants as they reduce the risk that blood clotting poses which reduces the risk of atheromas.

Question 21

Platelet inhibitors side effects

Answer 21

haemorrhage (excessive bleeding), nausea

Question 22

Obesity indicators

Answer 22

• BMI
• waist to hip ratio

Question 23

How to calculate bmi

Answer 23

weight in kg/height in meters squared

Question 24

Explain why high levels of sugars in a person’s diet could lead to obesity

Answer 24

Because sugars such a fructose are broken down into energy. If a person is consuming too much sugar, their energy intake would be higher than the output so the excess energy would be stored as fats, leading to a weight gain.