3.2.7 Heart Disease may be Associated with Specific Risk Factors

Question 1

Name the 3 stages of a cardiovascular disease

Answer 1

1. Atheroma Formation
2. Atheroma = Aneurysm and Thrombosis
3. Interrupted Blood Flow to Heart = Myocardial Infarction

Question 2

Describe how atheroma forms

Answer 2

1. Damage to endothelium of artery (e.g. by high blood pressure) = WBCs (mostly macrophages) and lipids from blood clump together under lining = form fatty streaks
2. Overtime, WBCs, lipids and connective tissue build up & harden to form fibrous plaque called atheroma

Question 3

What can the plaque (atheroma) do and cause?

Answer 3

Plaque blocks lumen of artery & restricts blood flow → causes blood pressure to increase

Question 4

When does coronary heart disease (CHD) occur?

Answer 4

• When coronary arteries have lots of atheromas = restricts blood flow to heart muscle
• Leads to myocardial infarction

Question 5

Name the 2 types of disease that affects arteries

Answer 5

1. Aneurysm
2. Thrombosis

Question 6

What is aneurysm?

Answer 6

Balloon-like swelling of artery

Question 7

Describe how an aneurysm occurs

Answer 7

1. Atheroma plaques damage and weakens arteries
   
   • Narrow arteries = ↑ blood pressure
2. When blood travels through weakened artery at high pressure = pushes inner layers of artery though outer elastic layer to form balloon-like swelling = aneurysm

Question 8

What may happen to an aneurysm?

Answer 8

Aneurysm may burst causing bleeding

Question 9

What is thrombosis?

Answer 9

Formation of blood clot

Question 10

Describe how thrombosis occurs

Answer 10

1. Atheroma plaque can burst through endothelium of artery
2. Damages artery wall & leaves rough surface
3. Platelets and fibrin accumulate at site of damage & form blood clot (thrombus)

Question 11

Thrombosis

What can the blood clot do & what can this lead to?

Answer 11

• Blood clot can cause complete blockage of artery or can become dislodged & block blood vessel elsewhere
• Debris from rupture can cause another blood clot to form further down artery

Question 12

Describe how a myocardial infarction (heart attack) occurs

Answer 12

1. Coronary artery blocked = area of heart muscle cut off from blood supply, no oxygen
2. Causes myocardial infarction (heart attack)

Question 13

What does a heart attack cause?

Answer 13

Damage and death of heart muscle

Question 14

What are the symptoms of a heart attack?

Answer 14

Pain in chest/upper body, shortness of breath and sweating

Question 15

Name 4 factors that increases the risk of cardiovascular disease

Answer 15

1. High blood pressure
2. Smoking
3. High blood cholesterol
4. Poor diet

Question 16

Explain how increasing blood pressure increases the risk of cardiovascular disease

Answer 16

1. High blood pressure increases risk of damage to artery walls
2. Damaged walls = increased risk of atheroma formation = ↑ blood pressure
3. Atheromas = blood clots
   
   • Block flow of blood to heart muscle = myocardial infarction

Question 17

Name 3 things that can increase blood pressure

Answer 17

Being overweight, not exercising and excessive alcohol consumption

Question 18

Describe how the nicotine from smoking can increase the risk of cardiovascular disease

Answer 18

Increases risk of high blood pressure

Question 19

Describe how the carbon monoxide from smoking can increase the risk of cardiovascular disease

Answer 19

1. Combines with haemoglobin and reduce amount of oxygen transported in blood
2. Reduces amount of oxygen available to tissues
3. If heart muscles ≠ oxygen → heart attack

Question 20

Smoking ______ the amount of _______ in blood

Answer 20

Smoking decreases the amount of antioxidants in blood

Question 21

Smoking

Explain how decreasing the amount of antioxidants in the blood can increase the risk of cardiovascular disease

Answer 21

• Antioxidants = important for protecting cells from damage
• Fewer antioxidants = cell damage in coronary artery walls more likely = atheroma formation

Question 22

Describe how high blood cholesterol can increase the risk of cardiovascular disease

Answer 22

• Cholesterol is main constituents of fatty deposits that form atheromas
• Atheromas = increased blood pressure & blood clots
• Blocks flow of blood to coronary arteries = myocardial infarction

Question 23

Describe how a poor diet can increase the risk of cardiovascular disease

Answer 23

• Diet high in saturated fat = high blood cholesterol levels (high LDLs)
• Diet high in salt = increases risk of cardiovascular disease ∵ increases risk of high blood pressure

Question 24

What do high-density lipoproteins (HDLs) do?

Answer 24

• Remove cholesterol from tissues and transport it to liver for excretion
• Help protect arteries against heart disease

Question 25

What do low-density lipoproteins (HDLs) do?

Answer 25

Transport cholesterol from liver to tissues (artery walls) = atheroma

Question 26

Name 2 factors that increase the risk of cardiovascular disease but can’t be controlled

Answer 26

• Having a genetic predisposition to coronary heart disease
• High blood pressure as a result of another condition e.g. some forms of diabetes