ABSTRACT
This study was carried out on 146 normal healthy volunteers in order to study the effect of postural changes and immersion in water to the level of diaphragm and to the level of the neck on cardiopulmonary reflexes by using non invasive technique. mercury sphygmomanometer for measuring the blood pressure, vitalograph spirometer to measure forced vital capacity [FVC] and forced expiratory volume in one second [FEV 1] and water tank is used for immersing the subjects. Measurement of blood pressure [BP], heart rate [HR], FVC, and FEV 1 was done in supine position, standing position, immersion in water up to the level of diaphragm and to the level of the neck. The volunteers are divided in two age groups, from 20-40 years [80subjects, 50 males and 30 females] and from 41-60 years [66 subjects, 50 males and 16 females]. Comparison between standing and supine, position indicate that. there was a significant increase in heart rate [HR]-diastolic blood pressure. [DBP], mean blood pressure [MBP] FEV1 and FVC, and significant decrease in systolic blood pressure [SBP] in standing position. During immersion in water [WI] to the level of diaphragm it was found that there was no significant changes in HR, SBP, DBP, MBP, FEV1 and FVC on comparison with supine position in both age groups, but during immersion in water [WI] to the level of neck, there was a significant increase in SBP, DBP 'and MBP, but a significant decrease in HR, FEV1 and FVC on comparison with supine position. It was found that the results of cardiopulmonary reflexes to the immersion in water up to the level of diaphragm, is significantly different from that in standing. position because WI act as an antagonist to the effect of gravity on cardiopulmonary reflexes when compared with standing position