The Major function of the respiratory system is to exchange oxygen and carbon dioxide. Inhaled oxygen enters the lungs and reaches the alveoli, the layers of the cells lining the alveoli and the surrounding capillaries are each only one cell thick and are in very close contact with each other, the barrier between air and blood averages about 1 micron in thickness. Oxygen diffuses quickly through the air-blood barrier into the blood in the capillaries. Similarly, carbon dioxide passes from the blood into the alveoli and is then exhaled.
Answer:
A group of similar cells make up a tissue. Several tissues make up an organ.
Explanation:
Um, Water is Water warmed by? that does not sound right XD
Answer:
to minimize the amount of oxygen introduced to the contents of the tube.
