PHYL 1010Y Chapter : Block C - Respiratory Physiology Gas Exchange.docx
Document Summary
Dalton"s law of partial pressures: in order to understand gas exchange, we must first understand the air we breathe, the atmosphere is a mixture of gases, including oxygen, carbon dioxide, nitrogen, and water, the combined pressure of these gases equals atmospheric pressure, at sea level, atmospheric pressure is 760 mm hg, each gas within the atmosphere is responsible for part of that pressure in proportion to its percentage in the atmosphere, oxygen comprises 20. 9% of the atmosphere. This value is known as the partial pressure of oxygen, and is written as p with the: the partial pressures of the four gases add up to 760 millimeters of mercury subscript o2, the total atmospheric pressure, this demonstrates dalton"s law of partial pressures, states that in a mixture of gases, the total pressure equals the sum of the partial pressures exerted by each gas, the partial pressure of each gas is directly proportional to its percentage in the total gas mixture.