Asked by Rusul Hamad on May 03, 2024
Verified
Why is the PO2 of the blood leaving pulmonary capillaries 104 mm Hg, but the blood leaving the lungs to enter the left atrium is 95 mm Hg?
A) Some O2 diffuses out of the blood as it travels through the pulmonary veins.
B) Some O2 is incorporated into bicarbonate ion, removing it from solution and reducing PO2.
C) Some CO2 in the alveoli is mixed with oxygenated blood from alveolar circulation.
D) Deoxygenated blood from bronchial circulation is mixed with blood from oxygenated alveolar circulation.
Pulmonary Capillaries
Tiny blood vessels in the lungs where gas exchange occurs, allowing for the uptake of oxygen and the release of carbon dioxide.
Left Atrium
One of the four chambers of the heart, receiving oxygenated blood from the lungs and pumping it into the left ventricle.
Bicarbonate Ion
A negatively charged ion (HCO3-) that is a significant component of the blood buffer system, regulating pH balance.
- Comprehend the determinants that modify or impact the constitution of alveolar air.
Verified Answer
CS
Colin SmithMay 04, 2024
Final Answer :
D
Explanation :
Deoxygenated blood from the bronchial circulation mixes with the oxygenated blood from the alveolar circulation as it returns to the heart, slightly lowering the oxygen partial pressure from what is seen in the pulmonary capillaries.
Learning Objectives
- Comprehend the determinants that modify or impact the constitution of alveolar air.