The disorders of the heart and blood vessels are called cardiovascular disorders. Cardiovascular disorders are the leading cause of untimely death in man.
2.8.1 Coronary Heart Diseases
Arteriosclerosis is hardening of the arteries. Atherosclerosis is the deposition of materials in the arteries. The deposits of cholesterol are called plaques which increase in size and begin to block arteries. Plaques can cause a clot to form on the irregular arterial wall. As long as the clot remains stationary, it is called a thrombus. If the clots breakaway, it may block artery at another location. The dislodged clot moving along with the blood is called an embolus. Hardened arteries lose their elasticity and may get ruptured, a process known as haemorrhage.
2.8.2 Myocardial Infarction
If the embolus or large plaque blocks vessel in one of the coronary arteries of the heart, a portion of the heart muscle will not get supply of oxygen. Due to lack of oxygen, this portion of heart muscle dies. Infarction means death due to lack of oxygen. The whole process is called myocardial infarction.