Question

The blood leaving the tissues becomes richer in

• A. carbon dioxide
• B. water
• C. heamoglobin
• D. oxygen

Answer 1

The correct option is A

carbon dioxide

The correct option is A.

Explanation of correct option:

1. Carbon dioxide is up in the blood when it leaves the body's tissues.
2. The major artery carries oxygenated blood from the heart to the lungs (aorta).
3. The cells of the body absorb oxygen as this blood flows into the capillaries of the organs.
4. At the same time, the amount of co2 emitted during respiration reaches the bloodstream.
5. The blood which has been deoxygenated (carrying carbon dioxide leaves tissues and enters the vena cava from where they are transported for oxygenation to the lungs again).

Explanation for Incorrect options:

Option B:

The levels of water and hemoglobin in tissues and the lungs are nearly identical.

Option C:

In both tissues and the lungs, hemoglobin concentrations are roughly similar.

Option D:

1. The blood flowing from the lungs to the heart seems to have an excess of oxygen saturation.
2. The pulmonary artery carries deoxygenated blood to the lungs, where that collects oxygen from inspired air and becomes oxygenated. Pulmonary veins carry oxygenated blood back to the heart.

Final answer:

The blood leaving the tissues becomes richer in carbon dioxide.