Vitalometry

Spirometry Aim : To record the Lung volumes and vital capacity using a student spirometer . Apparatus required : 1.Simple spirometer 2.KMnO4 solution 3.Water in a beaker 4.Kymograph Principle : The amount of air expired into the inner cylinder of the spirometer is recorded observing the graduated scale reading corresponding to the movable pointer . Procedure : 1.The pointer of the vitalometer was adjusted to zero mark . 2.The mouthpiece of the vitalometer was connected to the subject’s mouth. 3.The subject was asked to exhale normally into the spirometer after a normal inspiration through the nose to record the tidal volume. 4.The pointer was adjusted back again to zero. 5.The subject was asked to exhale forcefully into the spirometer at the end of the normal expiration after a normal inspiration through the nose and recorded the Expiratory reserve volume (ERV) 6.The pointer was adjusted back again to zero. 7.The subject was asked to make a deep inspiration through nose with the mouthpiece in the mouth, now the nostrils are closed using his own hand and was asked to exhale forcibly to the maximum through the mouth into the spirometer . The vital capacity was recorded. 8.The above procedure was repeated for three times with a gap of 2minutes interval in between and the highest value was reported. Precautions: 1.Pointer of the graduated scale should be adjusted to zero point every time before any recording. 2.The subject should be trained and encouraged to put his/her maximum effort possible. 3.The gap between each attempt should be a minimum of one to two minutes.

4.Raise and lower the bell a few times, finally raising it to its higher position in order to fill it with fresh room air. 5.Rinse the mouthpiece in KMnO4 and then wash in tap water everytime the subject is changed. Observation: Name :

Age :

Sex:

Occupation : Height :

Date of Observation: cms

Bodyweight :

kgs

In standing posture : I. Tidal volume :

ml

II.Expiratory reserve volume :

ml

III.Vital capacity I.Recording :

ml

II.Recording :

ml

III.Recording :

ml

Reporting value :

ml

Calculations: 1.Inspiratory reserve volume

:

ml ( VC – (TV+ERV)

2.Inspiratory capacity

:

ml(TV+IRV)

3.Expiratory capacity

:

ml (TV+ERV)

4.Minute ventilation

:

ml (TV X RR)Respiratoy rate

Result : The lung volumes and vital capacity of the subject was determined using the vitalograph /student spirometer.

Discussion : 1.Define vital capacity .give normal values: Vital capacity is the maximum volume of air that can be expired from the lungs by forceful effort following a maximal inspiration. Vital capacity = TV +ERV+IRV . 4.5 L in males and 3.3 L in females 2.What are the factors that affect vital capacity? Physiological factors : 1.Posture : Vital capacity is greater in standing posture than in sitting and lying postures. 2.Age : Vital capacity is high in young adults ,low in children and old people. Ageing causes a decrease in the compliance of lungs and chest wall. 3.Sex : Vital capacity is greater in males than in females due to greater the size of chest and muscle power. 4.Physical build : Vital capacity is low in obese and very thin.high in well built persons. 5.Pregnancy : Vital capacity is low as the chest expansion is decreased due to increased abdominal contents. 6.Physical training: Vital capacity is higher in trained athletes ,swimmers and divers than in intrained persons. Pathological factors : Vital capcity is decreased in: 1. Diseases of the chest wall eg.Kyphoscoliosis 2. Diseases of the lung eg,fibrosis,Emphysema 3. Diseases of the pleura eg,pleural effusion,pneumothorax 4. Diseases of the abdomen eg, abdominal tumours ,ascites

3.Why do vital capacity increases in standing posture than in sitting or supine posture ? Reasons : 1.In erect /standing posture more muscular effort is applied. 2.In erect posture ,diaphragm descends thereby the capacity of the thoracic cage increases. 3.In supine posture ,the abdominal viscera pushes the diaphragm upwards and thereby the thoracic cage capacity decreases in turn vital capacity also decreases. 4.What is the physiological significance of vital capacity? Vital capacity is the indicator of the strength of the respiratory muscles .The ability to put up maximum Inspiratory and expiratory effort of a person can be assessed by determining the vital capacity.