Patient Care Technician (PCT) AAH Practice Exam

Which organ is primarily responsible for the exchange of gases in the human body?

1. The heart

2. The liver

3. The lungs

4. The kidneys

The correct answer is: The lungs

The lungs are primarily responsible for the exchange of gases in the human body through the process of respiration. When we inhale, oxygen is brought into the lungs, where it moves across the alveoli's thin walls into the bloodstream. At the same time, carbon dioxide, a waste product of metabolism, moves from the blood into the alveoli to be exhaled. This effective gas exchange is crucial for maintaining the body's oxygen levels and removing carbon dioxide, making the lungs vital to respiratory function and overall homeostasis. In contrast, the heart's main role is to pump blood throughout the body, facilitating the transport of oxygen and nutrients to tissues and organs but not directly involved in gas exchange. The liver is primarily involved in detoxification, metabolism, and storage of nutrients, while the kidneys focus on filtering blood, removing waste products, and regulating fluid balance in the body. Each of these organs plays a specific and essential role, but it is the lungs that specifically handle the critical task of gas exchange.