AP BIOLOGY

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ANIMAL PHYSIOLOGY

GAS EXCHANGE IN HUMANS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
When blood reaches the tissue through the tissue capillaries, the partial pressure of oxygen in the blood is ____ than the partial pressure of oxygen in the cell body because cellular respiration uses ____ .When blood reaches the tissue through the tissue capillaries, the partial pressure of oxygen in the blood is ____ than that of body cells because cellular respiration uses ____ .
A
higher, carbon dioxidehigher, carbon dioxide
B
higher, oxygen higher, oxygen
C
lower, oxygen lower, oxygen
D
lower, carbon dioxidelower, carbon dioxide
Explanation: 

Detailed explanation-1: -At sea level without supplemented inspired oxygenation, the alveolar oxygen partial pressure (PAO2) is: PAO2 = (760-47) 0.21-40 / 0.8 = 99.7 mm Hg.

Detailed explanation-2: -Oxygen gets into the blood through tiny blood vessels around the alveoli. Red blood cells pick up the oxygen and deliver it to the body’s cells.

Detailed explanation-3: -The partial pressure of oxygen in the lungs or alveolar air is approximately 100 mm Hg, while that of oxygen in the venous blood in pulmonary arterial capillaries is 40 mm Hg on an average.

Detailed explanation-4: -Oxygen and carbon dioxide pass through these capillaries into the air sacs. As oxygen crosses over into the capillaries, the red blood cells capture it, while the carbon dioxide is unloaded into the lungs to be removed.

There is 1 question to complete.
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