Tidal Volume (T.V.): Volume of air inspired or expired during normal inspiration or expiration. It is approximately five hundred ml. i.e., a healthy man can inhale or exhale approximately six thousand to eight thousand ml of air, per minute.
Inspiratory Reserve volume (IRV): The maximum volume of air that can be inhaled during forced breathing, in addition to the 'tidal volume'. This is about two thousand five hundred ml to three thousand ml.
Expiratory reserve Volume (ERV): The maximum volume of air that can be exhaled during forced breathing, in addition to the 'tidal volume'. This is about 1000ml to 1100ml.
Residual volume (R.V): The volume of air remaining in the lungs even after forcible expiration. This is about 1100 ml to 1200 ml.
3y adding up a few "respiratory volumes' described above, one can derive various pulmonary capacities, which are useful in clinical diagnosis of zulmonary disorders.
I. Pulmonary gas exchange (External respiration)
Differences in pOa and pCOa of alveolar air and pulmonary capillaries favour the diffusion of Oa from the alveolar air into the blood in the pulmonary capillaries and the diffusion of COa in the opposite direction.
17. Systemic gas exchange (Internal respiration)
Difference in p02and pCOa of oxygenated blood in systemic capillaries and tissues favour the diffusion of Oz from systemic capillaries into tissues and the diffusion of COa in the opposite direction.
