GENERAL HISTOLOGY

Detailed explanation-1: -Respiration is the life-sustaining process in which gases are exchanged between the body and the outside atmosphere. Specifically, oxygen moves from the outside air into the body; and water vapor, carbon dioxide, and other waste gases move from inside the body into the outside air.

Detailed explanation-2: -The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation).

Detailed explanation-3: -Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.

Detailed explanation-4: -The carbon dioxide is dissolved in the blood, carried to the lungs by the circulation, and breathed out. Every living cell of our body carries out the energy-releasing process of respiration, where glucose (a simple sugar) is slowly “burnt” (oxidised) to give off carbon dioxide (excreted through the lungs) and water.

Detailed explanation-5: -Carbon dioxide is the waste product of the body that needs to be expelled out through exhalation. It is saturated with water vapours, that’s why water vapours also come out with it. So the correct answer is ‘Exhaled air’.