If a person's tidal volume decreases, but his or her respiratory rate remains unchanged, what is the most likely effect on the person's minute ventilation?

• A. Minute ventilation will decrease.
• B. Minute ventilation will remain the same.
• C. Minute ventilation will double.
• D. Minute ventilation will increase.

Answer: (A)

Verified step by step guidance

1. Understand the concept of tidal volume: Tidal volume is the amount of air inhaled or exhaled during a normal breath. It is a key factor in determining minute ventilation.
2. Understand the concept of respiratory rate: Respiratory rate is the number of breaths taken per minute. Minute ventilation is calculated by multiplying tidal volume by respiratory rate.
3. Write the formula for minute ventilation: $\mathrm{Minute}\mathrm{Ventilation}=\mathrm{Tidal}\mathrm{Volume}\times \mathrm{Respiratory}\mathrm{Rate}$
4. Analyze the scenario: If tidal volume decreases while respiratory rate remains unchanged, the product of tidal volume and respiratory rate will decrease, leading to a decrease in minute ventilation.
5. Conclude the effect: Based on the formula and analysis, the most likely effect is that minute ventilation will decrease.