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Carbon dioxide is produced continuously as the body's cells respire, and this CO 2 will accumulate rapidly if the lungs do not adequately expel it through alveolar ventilation. Alveolar hypoventilation thus leads to an increased PaCO 2 (a condition called hypercapnia). The increase in PaCO 2 in turn decreases the HCO − 3 /PaCO 2 ratio and ...
Minute ventilation (or respiratory minute volume or minute volume) is the volume of gas inhaled (inhaled minute volume) or exhaled (exhaled minute volume) from a person's lungs per minute. It is an important parameter in respiratory medicine due to its relationship with blood carbon dioxide levels .
The factors that determine the values for alveolar pO 2 and pCO 2 are: The pressure of outside air; The partial pressures of inspired oxygen and carbon dioxide; The rates of total body oxygen consumption and carbon dioxide production; The rates of alveolar ventilation and perfusion
While both ventilation and perfusion increase going from the apex to the base, perfusion increases to a greater degree than ventilation, lowering the V/Q ratio at the base of the lungs. The principal factor involved in the creation of this V/Q gradient between the apex and the base of the lung is gravity (this is why V/Q ratios change in ...
Tidal volume increases by 30–40%, from 0.5 to 0.7 litres, [9] and minute ventilation by 30–40% [9] [10] giving an increase in pulmonary ventilation. This is necessary to meet the increased oxygen requirement of the body, which reaches 50 ml/min, 20 ml of which goes to reproductive tissues. Overall, the net change in maximum breathing ...
Ventilation rate (V) is the total gas volume that enters and leaves the alveoli in a given amount of time, commonly measured per minute. To calculate the ventilation rate, the tidal volume (inhaled or exhaled gas volume during normal breath) is multiplied by the frequency of breaths per minute, which is represented by the formula:
Therefore it includes, firstly those units that are ventilated but not perfused, and secondly those units which have a ventilation-perfusion ratio greater than one. Alveolar dead space is negligible in healthy individuals, but it can increase dramatically in some lung diseases due to ventilation-perfusion mismatch.
The control of ventilation is the physiological mechanisms involved in the control of breathing, which is the movement of air into and out of the lungs. Ventilation facilitates respiration. Respiration refers to the utilization of oxygen and balancing of carbon dioxide by the body as a whole, or by individual cells in cellular respiration. [1]