Smoking and Coronary Heart Disease

Question 1

What is the effect of carbon monoxide in cigarette smoke?

Answer 1

• Binds irreversibly with haemoglobin
• Reduces oxygen carrying capacity of blood
• Heart has to work harder to supply tissue with enough oxygen
• Leads to raised blood pressure and increased risk of coronary heart disease and stroke
• Oxygen-carrying capacity of blood may be insufficient to supply heart tissue during exercise
• Can cause angina, or myocardial infarction

Question 2

What is the effect of nicotine in cigarette smoke?

Answer 2

• Increases production of the hormone adrenaline
• Increases heart rate and blood pressure
• Greater risk of suffering coronary heart disease or stroke
• Also makes red blood cells more ‘sticky’
• Increased risk of thrombosis and therefore strokes and myocardial infarction

Question 3

What factors affect blood pressure?

Answer 3

• Smoking
• Prolonged stress
• Diet
• Lack of exercise

Question 4

Why does high blood pressure increase the risk of coronary heart disease?

Answer 4

• Due to already higher pressure in the arteries, the heart must work harder to pump blood into them and is therefore more prone to failure
• Higher blood pressure within arteries means that they are more likely to develop an aneurysm and burst, causing haemorrhage
• To resist high pressure, artery walls become thicker and harder, restricting blood flow, increasing likelihood of thrombosis

Question 5

What is an aneurysm?

Answer 5

• Atheromas that lead to thombus also weaken the artery wall
• These weakened points swell to form a balloon-like, blood filled structure called an aneurysm
• If this bursts, it leads to haemorrhage

Question 6

What is a stroke?

Answer 6

• A brain aneurysm

- known as a cerebrovascular accident

Question 7

What is an atheroma?

Answer 7

• Fatty deposit that forms within the wall of an artery
• Starts as accumulations of white blood cells that have taken up low-density lipoproteins
• Enlarge to form an atheromatous plaque
• Narrows lumen of artery, restricting blood flow, increasing risk of thrombosis and aneurysm

Question 8

What is thrombosis?

Answer 8

• A blood clot which may block the blood vessel, reducing or preventing blood flow to tissues beyond it
• Tissue often dies through lack of oxygen, glucose and nutrients

Question 9

Effect of high blood pressure?

Answer 9

• The heart must work harder and is therefore prone to failure
• An aneurysm may develop causing a haemorrhage
• The artery walls may thicken, restricting blood flow, increasing risk of thrombosis