Which of the following best describes how the flu virus may impact the respiratory system?

• A. It infects cells lining the respiratory tract, causing inflammation and symptoms such as coughing and sore throat.
• B. It causes the kidneys to filter out more glucose from the blood.
• C. It directly destroys red blood cells, leading to anemia.
• D. It increases the production of digestive enzymes in the stomach.

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by identifying the primary function of the respiratory system, which is to facilitate gas exchange (oxygen intake and carbon dioxide removal) through structures like the lungs, trachea, and bronchi.
2. Step 2: Understand the nature of the flu virus (influenza virus). It primarily targets the respiratory system by infecting epithelial cells lining the respiratory tract, leading to inflammation and damage.
3. Step 3: Recognize the symptoms caused by the flu virus in the respiratory system, such as coughing, sore throat, and difficulty breathing, which are direct results of the inflammation and irritation of the respiratory tract.
4. Step 4: Eliminate the incorrect options by analyzing their relevance to the flu virus. For example, the flu virus does not impact kidney function, red blood cells, or digestive enzyme production, as these are unrelated to its primary mode of infection.
5. Step 5: Conclude that the best description of how the flu virus impacts the respiratory system is that it infects cells lining the respiratory tract, causing inflammation and symptoms such as coughing and sore throat.