Certified Transport Registered Nurse Certification Practice Exam

What is a common role of hemoglobin in gas transport?

1. Oxygen transport only

2. Carbon dioxide transport only

3. Both oxygen and carbon dioxide transport

4. Only nitrogen transport

The correct answer is: Both oxygen and carbon dioxide transport

Hemoglobin plays a critical role in both the transport of oxygen and carbon dioxide within the bloodstream. This protein, found in red blood cells, has a high affinity for oxygen, allowing it to bind to oxygen molecules in the lungs where oxygen levels are high. Once bound, hemoglobin carries oxygen to the tissues and organs throughout the body, where it is released for use in metabolic processes. In addition to transporting oxygen, hemoglobin also assists in the transport of carbon dioxide. After delivering oxygen, hemoglobin can pick up carbon dioxide—a waste product of cellular respiration—from the tissues. It does this by binding to carbon dioxide molecules and facilitating their transport back to the lungs, where carbon dioxide is expelled from the body when we exhale. This dual functionality of hemoglobin in transporting both gases is vital for maintaining proper oxygen levels in the body and effectively removing carbon dioxide, thus supporting overall respiratory function and metabolic processes. The ability of hemoglobin to handle both gases emphasizes its importance in respiratory physiology.