To determine the vital capacity.


Spirometer - conists of an outer container filled with water in which a gas bell flows. It is attached to a chain which passes over a pulley with a needle which denotes the volume. The gas bell has a very little inertia and friction. The inlet tube is a corrugated rubber canvas bearing a metalic mouth piece and is attached to a pipe fitted at the botton of the spirometer.


Adjust the pointer so that it indicate zero. Breath 6-8 times and after inhaling fully expire as deeply as possible closing the nostrils into the mouth piece. The pointer indicates the volume and repeat the procedure twice at 2 minutes interval and also note the posture during the experiment.

Factors affecting vital capacity

1. Relation to height

In males height in cm. x 25

In females height in cm. x 20

In athlets height in cm. x 29

2. Relation to body surface

Males - 2.5 Ii! m2 of body surface area.

Females -2.1 Ii! m2of body surface area.

3. Occupation of individual

Athlets, swimmers, and divers have higher vital capacity and it also increases by practice.

4. Posture

Vital capacity will below in lying position and will be higher in standing position.

Variations in Vital Capacity under Pathological conditions.

Vital Capacity is low under folowing conditions.

1. Mechanical interfearance with the enlargement of thoracic cavity eg: pregnancy. ascitis.

2. Deformities of spinal column, ribs,sternum and the conditions involving lung directly eg: Pnenumonia, TB.

3. Depression of respiratory centres by narcotics.

4. Obstruction of respiratory passage

5. Pulmonary oedema due to any cause.

Nornal Vital Capacity:

4-4.5 liter


1. In which pathological conditions do vital capacity differ?

2. State reasons for the above?


Vital capacity is ml.







Kumkum / safron - Crocus sativus

 Medicinal Plant / herbs

Crocuses belong to the family Iridaceae. The saffron crocus is classified as Crocus sativus, It is a shrub. Leaves are seen towards the base of the stem and are compactly arranged.Read More about safron.....