44. In human tissues, oxygen is exchanged with carbon dioxide in the
Answer: B
Oxygen is exchanged with carbon dioxide in the capillaries.
In human tissues, the exchange of oxygen and carbon dioxide occurs primarily in the capillaries, where the blood comes into close contact with surrounding tissues.
A) veins
Veins are responsible for carrying deoxygenated blood back to the heart, but they do not participate in the exchange of gases. The exchange of oxygen and carbon dioxide occurs at the capillary level, not in the veins.
B) capillaries
Capillaries are the sites where oxygen is exchanged for carbon dioxide in human tissues. Their thin walls facilitate the diffusion of gases, allowing oxygen to enter the tissues while carbon dioxide is released into the bloodstream.
C) ventricles
Ventricles are chambers of the heart that pump blood either to the lungs or the rest of the body. They do not play a role in the exchange of gases; that function is performed by the capillaries.
D) arteries
Arteries carry oxygen-rich blood away from the heart to various parts of the body, but they do not facilitate the exchange of gases. The exchange occurs in the smaller capillaries, where blood and tissues interact directly.
Conclusion
The correct answer is capillaries, as they are specifically designed for the exchange of gases between blood and tissues. All other options—veins, ventricles, and arteries—are involved in the transportation of blood but do not serve the function of gas exchange. Thus, they cannot be considered correct in the context of this question.