12th Zoology



A sphygmomanometer is an instrument used to measure blood
pressure. The word is derived from the Greek sphygmus (pulse) plus the
scientific (physical) term manometer.

Arterial blood pressure is the force of pressure, which the blood is
exerting on the walls of the blood vessels in which it flows. The blood
pressure in the artery varies during the cardiac cycle. The cardiac cycle is
defined as the cycle of events that take place during one systole and diastole
of the heart. Systole refers to contraction and diastole the relaxation. During
ventricular systole, when the left ventricle is forcing blood into the aorta the
pressure rises to a peak which is referred to as systolic pressure. During
diastole the pressure falls and the lowest value reached is referred to as
diastolic pressure.

The blood pressure depends partly on the force and volume of blood
pumped by the heart and partly on the contraction of the muscles in the walls of the arterioles. Blood pressure changes during physical exercise, during
anxiety and emotion and in sleep etc. However a prolonged or constant
elevation of blood pressure, a condition known as hypertension can increase
a person’s risk for heart attack, stroke, heart and kidney failure and other
health problems. It is always suitable to measure blood pressure when a
person is in a relaxed and in resting condition.

The normal blood pressure value is 120/80mm Hg, in which ‘120’
denotes the systolic pressure and 80 the diastolic pressure.
There are two types of sphygmomanometer viz., Monometric type
and 2. Digital (modern) type.


1. Sphygmomanometer helps to estimate the state of blood circulation and
the working of heart.
2. Sphygmomanometer helps to diagnose pathological conditions such as
hypertension (increased BP) and hypotension (reduction in BP).

Related Topics in Zoology:

Bio Zoology All Important Topics

  1. Livestock and Management

  2. Important cattle breeds and their characteristics

  3. Milch breeds (or) Dairy breeds

  4. Dual purpose breeds & Draught breeds

  5. Exotic breeds of cattle

  6. Common diseases and control in Cattle – Contagious diseases

  7. Non-contagious diseases – Cattle

  8. Techniques adopted in cattle breeding

  9. Poultry Breeds

  10. Farming methods

  11. Poultry byproducts

  12. Fish Pond

  13. Edible Fishes Of Tamilnadu

  14. Medical Lab Techniques – Stethoscope

  15. Sphygmomanometer

  16. Haemocytometer

  17. Urine Sugar analysis

  18. ECG Electrocardiogram

  19. Computed Tomography CT

  20. Endoscopy (Laproscopy) techniques , Artificial Pacemaker

  21. Autoanalyser

Unit 7. THEORIES OF EVOLUTION Topic List Zoology

  1. Theories Of Evolution Introduction

  2. Lamarck Laws

  3. Neo Lamarckism

  4. Darwinism

  5. Theory of Natural Selection

  6. Objections to Darwinism

  7. Modern concept of Natural Selection

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