Cardiovascular Disease Flashcards
How is an atheroma formed?
If damage occurs to the endothelium of an artery, white blood cells and lipids from the blood clump together under the lining to form fatty streaks. Over time, more white blood cells, lipids and connective tissue build up and harden to form a fibrous plaque (atheroma)
What do atheroma do?
Partially block the lumen of an artery and restricts blood flow, which causes blood pressure to increase
What are two types of disease that affect arteries?
- Aneurysm
- Thrombosis
What is an aneurysm?
A balloon-like swelling of an artery
Explain aneurysm formation
Atheroma plaque damage and weaken arteries. They narrow arteries, increasing blood pressure. When blood flows through a weakened artery at high pressure, it can push inner layers of the artery through the outer elastic layer to form an aneurysm. An aneurysm may burst, causing a haemorrhage
What is thrombosis?
Formation of a blood clot
Explain thrombosis
An atheroma plaque can rupture the endothelium of an artery, damaging the artery wall, leaving a rough surface. Platelets and fibrin accumulate at the site of damage and form a blood clot. This blood clot can cause a complete blockage of the artery, or it can dislodge and block a blood vessel elsewhere in the body
Explain myocardial infarction
The heart muscle is supplied with blood by the coronary arteries. This blood contains oxygen needed by heart muscle cells to carry out respiration. If a coronary artery becomes completely blocked an area of the heart muscle will be completely cut off from its blood supply, receiving no oxygen. This causes myocardial infarction - causing death and damage of the heart muscle
What are three risk factors of cardiovascular disease?
- High blood cholesterol and poor diet
- Cigarette smoking
- High blood pressure
How does high blood cholesterol and poor diet increase risk of cardiovascular disease?
Cholesterol is found in the fatty deposits that form atheroma. Atheroma can lead to high blood pressure and blood clots. This could block the flow to the coronary arteries, which could lead to MI. A diet high in saturated fat is linked to high cholesterol levels. A diet high in salt increases risk of high blood pressure
How does cigarette smoking increase the risk of cardiovascular disease?
Cigarette smoke contains both nicotine and carbon monoxide. Nicotine increases risk of high blood pressure. Carbon monoxide combines with Hb and reduces amount of oxygen transported in the blood, reducing amount of oxygen available to tissue. Smoking also decreases amount of antioxidants in the blood - these help protect cells from damage. Fewer antioxidants means cell damage is more likely, this can lead to atheroma formation
How does high blood pressure increase the risk of cardiovascular disease?
High blood pressure increases risk of damage to artery walls, increasing risk of atheroma formation, causing further increase in blood pressure. Atheroma can cause blood clots. A blood clot could block flow of blood to heart muscle, possible resulting in MI
