NEET PG DENTAL EXAM

EMBRYOLOGY

RESPIRATORY SYSTEM

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
During cellular respiration, what happens to the carbon dioxide?
A
It leaves the alveoli and is exhaled from the lungs
B
It leaves the bloodstream and enters the alveoli
C
It leaves the cells and enters the bloodstream
D
It leaves the alveoli and enters the bloodstream
Explanation: 

Detailed explanation-1: -Once the venous blood returns to the lungs, the carbon dioxide diffuses out of the bloodstream, through the capillaries, and into the alveoli from where it is expelled, during which time oxygen simultaneously binds with hemoglobin to be carried back to the tissues.

Detailed explanation-2: -The walls of the alveoli share a membrane with the capillaries. That’s how close they are. This lets oxygen and carbon dioxide diffuse, or move freely, between the respiratory system and the bloodstream. Oxygen molecules attach to red blood cells, which travel back to the heart.

Detailed explanation-3: -At each cell in your body, oxygen is exchanged for a waste gas called carbon dioxide. Your bloodstream then carries this waste gas back to the lungs where it is removed from the bloodstream and then exhaled. Your lungs and respiratory system automatically perform this vital process, called gas exchange.

Detailed explanation-4: -Carbon dioxide (CO2) is a waste product of cellular metabolism. You get rid of it when you breathe out (exhale). This gas is transported in the opposite direction to oxygen: It passes from the bloodstream – across the lining of the air sacs – into the lungs and out into the open.

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