Question

1.If metabolic rate decreases, what happens as a result to minute ventilation, and what function does this change serve?

2. If metabolic rate increases, what happens as a result to:

            a. the amount of oxygen consumed by tissues?

            b. the amount of carbon dioxide produced by tissues?

            c. the PO2 of systemic venous blood plasma (i.e. mixed venous blood)?

            d. the PCO2 of systemic venous blood plasma (i.e. mixed venous blood)?

            e. the bicarbonate concentration of systemic venous blood plasma (i.e. mixed venous blood)?

            f. the chloride concentration of systemic venous blood plasma (i.e. mixed venous blood)?

Answer 1

Question no 1)

Minute volume is the volume of air inhaled or exhaled by a person. When the metabolic of the person decreases it results in the reduction of the oxygen need of each cell in body . The carbon dioxide produced by each cell in the body also reduces

In general it is said they the minutes ventilation is directly proportional to the amount of oxygen needed by the cells and amount of carbon dioxide excreted by the cells

Since in case of reduced metabolic rate the amount of oxygen need is decreased and carbon dioxide produced is reduced so the minute ventilation decreases( As mentioned earlier it is directly proportional to need for O2 and amount of carbon dioxide produced)

Sub part 1) the function that this change serve is that when the body requirement for oxygen is reduced then the intake of oxygen will also be reduced . This will also help in maintainance of normal physiological movement of oxygen in blood vessels .

Question no 2)

Part a) when metabolic rate increases the amount of oxygen consumed by tissue increase. This is because when energy need increases in our body needs more oxygen to burn sugar.

Part b)

The amount of co2 produced will also increase , because when metabolic rate increases the cellular respiration that is the burning of sugar with help of oxygen increases they by the byproduct of these reactions like carbon dioxide also increase.

Part c)

The partial pressure of oxygen in systemic venous plasma decrease as the need for oxygen in cells will increase there by reducing the amount of oxygen remaining in the veins

Part d

The partial pressure of carbon dioxide will increase as the amount of carbon dioxide produced by the cells also increase . These extra Carbon dioxide produced in cell reaches the vein and increase the partial pressure of co2.