THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The pressure of a gas is then a measure of the average linear momentum of the moving molecules of a gas. The pressure acts perpendicular (normal) to the wall; the tangential (shear) component of the force is related to the viscosity of the gas.

Detailed explanation-2: -Alveolar pressure determines whether air will flow into or out of the lungs. When alveolarpressure is negative, as is the case during inspiration, air flows from the higher pressure at the mouth down the lungs into the lower pressure in the alveoli.

Detailed explanation-3: -Therefore, at sea level, where atmospheric pressure is 760 mmHg, the partial pressures of the various gases can be estimated to have partial pressures of approximately 593 mmHg for nitrogen, 160 mmHg for oxygen, and 7.6 mmHg for argon.