Class 11 Biology Body Fluids Circulation Disorders of circulatory system

Disorders of circulatory system

High Blood Pressure (Hypertension)

  • Hypertension is the term for blood pressure that is higher than normal (120/80).
  • 120 mm Hg is the systolic, or pumping, pressure and 80 mm Hg is the diastolic, or resting, pressure.
  • If repeated checks of blood pressure of an individual is 140/90 (140 over 90) or higher, it shows hypertension.
  • High blood pressure leads to heart diseases.

Coronary Artery Disease (CAD):

  • Coronary Artery Disease, often referred to as atherosclerosis, affects the vessels that supply blood to the heart muscle.
  • CAD caused by deposits of calcium, fat, cholesterol and fibrous tissues, which makes the lumen of arteries narrower.


  • It is also called ‘angina pectoris’.
  • A symptom of acute chest pain appears when no enough oxygen is reaching the heart muscle.
  • Angina can occur in men and women of any age.
  • It occurs due to conditions that affect the blood flow.

Heart failure

  • Heart failure means the state of heart when it is not pumping blood effectively enough to meet the needs of the body.
  • Heart failure is not the same as cardiac arrest or a heart attack.
  • Cardiac arrest is when the heart stops beating, whereas heart attack is when the heart muscle is suddenly damaged by an inadequate blood supply.


Fig. Coronary artery disease

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