QS Study

Normal Function of Blood Pressure

Blood pressure is the lateral pressure exerted by blood in per unit area of vessel wall while flowing through it. It is the force that moves blood through our circulatory system. It is a vital force because oxygen and nutrients would not be pushed around our circulatory system to nourish tissues and organs without blood pressure.

The function of Blood Pressure

(a) It is essential for circulating blood through a circulatory tree.

(b) It provides a motive force for the filtration at the capillary, bed which is essential for –

  • Tissue nutrition
  • Urine formation
  • Lymph formation
  • For venous return.

As our heart beats, it pumps our blood around our body so that our muscles can get all the power and oxygen they need. To do this, our heart pushes our blood through a network of blood vessels called arteries. As the blood travels through the arteries it pushes against the sides of these blood vessels and the strength of this pushing is called blood pressure.

There is no ‘normal’ or ‘ideal’ blood-pressure reading. The following figures should only be used as a guide:

  • optimal <120/<80
  • normal 120-129/80-84
  • high-normal 130-139/85-89
  • mild hypertension 140-159/90-99
  • moderate hypertension 160-179/100-109
  • severe hypertension ≥180/≥110