spirometer

Spirometer and forced vital capacity:

A spirometer is a machine which measures the volume of air that is inhaled and exhaled from the lungs. It can also differentiate between deep and shallow breaths. It is used to monitor the lung function of patients with conditions such as asthma, emphysema and bronchitis and to monitor improvements following surgery to the lungs or chest. Forced vital capacity is the amount of air that can be forced out after a really deep breath in. It is used to determine the severity of various lung diseases including asthma and COPD. It also varies with age, gender and fitness levels.

How a spirometer works:

go on powerpoint

tidal reading on powerpoint

Vital capacity

IRV +TV+ ERV

Inspiratory reserve volume

VC - ( TV+ ERV)

Total lung capacity

IRV +ERV +TV +RV

Effect of exercise on breathing rate, oxygen consumption and spirometer trace:

When you exercise, your body needs more energy which means it uses more oxygen. To get enough oxygen, the breathing rate will increase. This increase in breathing rate will continue for a while after exercise stops because it is needed to convert any lactic acid produced by anaerobic respiration into carbon dioxide and water – this is known as paying the oxygen debt. During exercise the slope of the spirometer trace will be steeper than when not exercising. This is because overall more oxygen is used. The amount of oxygen used is the same as the amount of carbon dioxide produced. The carbon dioxide does not go back into the spirometer chamber because it is absorbed by the soda lime. Consequently, the overall volume of gas left in the chamber will decrease more rapidly than when not exercising