3.2.7 Heart Disease may be Associated with Specific Risk Factors Flashcards Preview

A-level Biology Oxford AQA > 3.2.7 Heart Disease may be Associated with Specific Risk Factors > Flashcards

Flashcards in 3.2.7 Heart Disease may be Associated with Specific Risk Factors Deck (26)
Loading flashcards...
1

Name the 3 stages of a cardiovascular disease

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

2

Describe how atheroma forms 

  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

3

What can the plaque (atheroma) do and cause?

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

4

When does coronary heart disease (CHD) occur?

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

5

Name the 2 types of disease that affects arteries

  1. Aneurysm
  2. Thrombosis

6

What is aneurysm?

Balloon-like swelling of artery

7

Describe how an aneurysm occurs

  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

8

What may happen to an aneurysm?

Aneurysm may burst causing bleeding

9

What is thrombosis?

Formation of blood clot 

10

Describe how thrombosis occurs

  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)

11

Thrombosis

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

  • 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

12

Describe how a myocardial infarction (heart attack) occurs

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

13

What does a heart attack cause?

Damage and death of heart muscle

14

What are the symptoms of a heart attack?

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

15

Name 4 factors that increases the risk of cardiovascular disease

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

16

Explain how increasing blood pressure increases the risk of cardiovascular disease

  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

17

Name 3 things that can increase blood pressure

Being overweight, not exercising and excessive alcohol consumption

18

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

Increases risk of high blood pressure

19

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

  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

20

Smoking ______ the amount of _______ in blood

Smoking decreases the amount of antioxidants in blood

21

Smoking

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

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

22

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

  • 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

23

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

  • 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

24

What do high-density lipoproteins (HDLs) do?

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

25

What do low-density lipoproteins (HDLs) do?

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

26

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

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

Decks in A-level Biology Oxford AQA Class (41):