Cardiovascular Diseases

- The wall of the artery is made of many layers.

- The endothelium is usually smooth and unbroken.

- If damage occurs, white blood cells and lipids clump together under the lining.

- Over time more WBC and lipids as well as connective tissues build up and harden to form a plaque called atheroma. 

- This plaque partially blocks the lumen of the artery and restrict blood flow, which causes blood pressure to increase.

- Coronary heart disease occurs when the coronary arteries are blocked by atheroma leading to myocardial infraction ( heart attack ).

- Atheroma plaques damage and weaken the arteries.

- They also narrow the lumen by blocking it, causing high blood pressure.

- This may push the inner lining through the outer elastic layer to form a balloon like swelling- an aneurysm.

- It can burst, causing bleeding.

Thrombosis 

- An atheroma plaque can burst through the inner lining of an artery.

- This damages the wall leaving a rough surface.

- Platelet and fibrins gather around the damaged area forming a blood clot, this can block the artery completely.

Cholesterol 

- If the blood cholesterol is too high, the risk of cardiovascular diseases is high.

- Cholesterol is one of the main lipids causing Atheroma.

- Atheroma leads to high blood pressure and formation of blood clots.

- This blocks the flow of blood in the arteries.

Smoking 

- Both Nicotine (causes high blood pressure) and Carbon monoxide are found in cigarette.

- Carbon Monoxide combines with Haemoglobin and reduces the saturation of it with oxygen, so it reduces the amount of oxygen available to cells.

- If heart muscles don't receive enough blood, it can lead to heart attack.

- Smoking also reduces antioxidants in blood- they protect cells from damage.