Cardiovascular Disease

Question 1

What is atherosclerosis?

Answer 1

When fatty deposits block an artery directly

Question 2

Describe the sequence of atherosclerosis

Answer 2

1 endothelium becomes damaged or dysfunctional
2 the inner lining of artery is breached and there is an inflammatory response
3 white blood cells leave the blood vessel + move into wall of artery where they accumulate cholesterol
4 a fatty deposit builds up called an atheroma
5 calcium salts and fibrous tissue build up site resulting in a swell called a plaque
6 plague is hard so artery loses some of its elasticity
7 plaque also causes lumen of artery to narrow, makes it difficult for heart to pump blood + increases blood pressure

Question 3

What are the stages in the clotting cascade?

Answer 3

1 Platelets and damaged tissue release the protein thromboplastib
2 Thromboplastin activates an enzyme catalysing conversion of protein prothrombin to thrombin (calcium ions, vitamin K must be present)
3 Thrombin catalysed conversion of the soluble protein fibrinogen to the insoluble fibrin
4 A mesh of fibrin forms, trapping more platelets and RBCs, forming a clot

Question 4

What is cardiovascular disease?

Answer 4

Diseases of the heart and circulation

Question 5

What are features of a well designed study?

Answer 5

• clear stated aim/hypothesis
• design appropriate for question
• symptoms of people w/ disease are clearly defined
• use correct measurement method for DV and repeating
• timescale of study is suitable for exposure to + development of disease

Question 6

What are the two types of studies for identifying risk factors ?

Answer 6

Cohort - following a large group of people over time to see who does and doesn’t develop the disease (prospective)
Case-controlled - comparing people with the disease to those without (retrospective)

Question 7

Identify some risk factors for CVD + why

Answer 7

Low-density lipoproteins (high blood cholesterol), smoking (carbon monoxide increases deposition of cholesterol in atheroma formation), salt (kidneys retain too much water = higher fluid content = higher blood pressure), exercise (increases HDLs and lowers LDLs), antioxidants, obesity, alcohol, age (arteries become less elastic), sex (women naturally have higher HDL levels), genetics, stress

Question 8

Why is obesity a risk factor for CVD?

Answer 8

• higher blood sugar = higher blood pressure, makes blood more viscous
• increases risk of CHD even without other factors

Question 9

Why is smoking a risk factor for CVD?

Answer 9

• contains free radicals
• contains carcinogens —> cancer causing
• contains carbon monoxide —> binds to haemoglobin
• nicotine stimulates adrenaline —> increases heart rate
  -chemicals in smoke damage artery lining

Question 10

What are main treatments for high blood pressure?

Answer 10

Antihypertensives = drugs treating high blood pressure
- Diuretics - help reduce fluid buildup in the body
- help kidneys remove salt + water through urine
- lowers amnt of fluid flowing through veins + arteries
Beta blockers
- block the effect of adrenaline
- causes heart to beat slower and with less force
ACE inhibitors
-reduce synthesis of the hormone angiotensin II
- which causes vasoconstriction of blood vessels
Calcium channel blockers
- blocks calcium channels in artery lining, prevents them contracting

Question 11

What are treatments to reduce blood cholesterol?

Answer 11

• Diet low in saturated fats and cholesterol
• Statins = medication which inhibits an enzyme involved in LDL production in the liver
• Anticoagulants & platelet inhibitors = reduce blood clotting
  e.g. aspirin + clopidogrel reduce stickiness of platelets and thus likelihood of clot formation
  e.g. warfarin - interferes with vitamin K production and affects synthesis of clotting