Assuming ideal, healthy lung and cardiac conditions, what is the change in percentage of oxygen in blood over $1$ minute? (Round off the answer to one decimal place.)
Calculating Oxygen Percentage Change in Blood
This solution details the steps to calculate the change in the percentage of oxygen in the blood based on respiration and cardiac output.
Oxygen Consumption Calculation
- Calculate Total Inspired Oxygen Volume:
Inspired Oxygen = Breathing Rate × Tidal Volume × Percentage of Oxygen Inspired
Inspired Oxygen = $12 \text{ breaths/min} \times 500 \text{ ml/breath} \times 0.20 = 1200 \text{ ml/min}$
- Calculate Total Expired Oxygen Volume:
Expired Oxygen = Breathing Rate × Tidal Volume × Percentage of Oxygen Expired
Expired Oxygen = $12 \text{ breaths/min} \times 500 \text{ ml/breath} \times 0.16 = 960 \text{ ml/min}$
- Determine Net Oxygen Consumed:
Oxygen Consumed = Total Inspired Oxygen - Total Expired Oxygen
Oxygen Consumed = $1200 \text{ ml/min} - 960 \text{ ml/min} = 240 \text{ ml/min}$
This represents the amount of oxygen removed from the blood circulation by the body's tissues each minute.
Percentage Change in Blood Oxygen
The question asks for the change in the percentage of oxygen in the blood over 1 minute. This is interpreted as the proportion of the total blood circulated (cardiac output) that carries the oxygen consumed by the tissues.
- Relate Oxygen Consumption to Cardiac Output:
Cardiac Output = $5 \text{ liters/min} = 5000 \text{ ml/min}$
The oxygen consumed ($240 \text{ ml/min}$) is transported by the blood pumped by the heart.
- Calculate Percentage Change:
Percentage Change = $ \frac{\text{Oxygen Consumed}}{\text{Cardiac Output}} \times 100\% $
Percentage Change = $ \frac{240 \text{ ml/min}}{5000 \text{ ml/min}} \times 100\% $
Percentage Change = $ 0.048 \times 100\% = 4.8\% $
The change in the percentage of oxygen in the blood over 1 minute is $4.8\%$.
Important Questions from Respiratory System
- The vital capacity, tidal volume, and inspiratory reserve volume of the lungs of a healthy individual are 4600 milliliters (mL), 500 mL, and 2500 mL, respectively. The expiratory reserve volume of the lungs of this individual is _______ mL.
(Round off to the nearest integer) - Which of the following relations is/are CORRECT in terms of various lung volume measurements?
- Which one of the following epithelial cell types is primarily located in the tracheal mucosa of a healthy adult human?
