 |
| Blood Pressure |
|
| The lateral pressure that the blood exerts against the walls of the blood vessels is called blood pressure. It is caused by |
| |
| a) contraction of the ventricles |
| |
| b) resistance to the passage of blood through arterioles and capillaries. |
| |
| The pressure existing in the arteries is called arterial blood pressure. The blood pressure is high during systole and is called systolic blood pressure. It is low during diastole and it is called diastolic blood pressure. The difference between these two pressures is called pulse pressure |
| |
| The blood pressure is high in the aorta situated near the heart. It gradually decreases as it goes away from the heart. It is low in the capillairies. The blood pressure is minimum in the veins. |
| |
| For clinical purpose, the blood pressure is measured from the large arteries of the arm. The instrument used is called a sphygmomanometer. The systolic blood pressure in an ideal man is 120 mm of Hg and the diastolic blood pressure is 80 mm of Hg. Blood pressure is measured in millimeters of mercury (mm. Hg) |
| |
