Question

Which of the following would have the same $O_2$ content?

• A. Blood entering the lungs and blood leaving the lungs
• B. Blood entering the right side of the heart and blood leaving the right side of the heart
• C. Blood entering the right side of the heart and blood leaving the left side of the heart
• D. Blood entering the tissue capillaries and blood leaving the tissue capillaries

Answer 1

Answer: (B)

Blood entering the right side of the heart i.e., right atrium is a deoxygenated blood having partial pressure of $40mmHg$. Blood leaving the right side of the heart i.e., right ventricle will also have almost same partial pressure as the blood is moving from right atrium to right ventricle and also no exchange of gases occurs in this path.