Gas Exchange and Blood Chemistry

Internal respiration involves the exchange of gases between blood and body tissues, occurring through simple diffusion due to a partial pressure gradient. Oxygen diffuses from the alveoli into the bloodstream, forming oxyhemoglobin. In tissues, oxygen dissociates from hemoglobin due to a pressure gradient, facilitating cellular respiration. Carbon dioxide, produced by cellular respiration, diffuses from tissues into the blood, transported as carbamino hemoglobin or bicarbonate ions. In the lungs, carbon dioxide is expelled during expiration.

What is the primary function of internal respiration?

• Exchange of gases between the atmosphere and lungs

• Exchange of gases between blood and body tissues

• Transport of nutrients to cells

• Regulation of body temperature

What percentage of oxygen enters the plasma during inspiration?

• 2%

• 20%

• 10%

• 5%

What is the partial pressure of oxygen in the tissues?

• 40 mmHg

• 100 mmHg

• 60 mmHg

• 80 mmHg

What happens to hemoglobin when it loses oxygen?

• It turns burgundy

• It becomes lighter in color

• It remains unchanged

• It becomes transparent

Why is the partial pressure of carbon dioxide higher in tissues?

• Because of oxygen consumption

• Due to cellular respiration

• Due to low oxygen levels

• Because of high blood flow

How is carbon dioxide primarily transported in the blood?

• As carbamino hemoglobin

• As dissolved gas

• As bicarbonate ions

• As carbonic acid

What compound is formed when carbon dioxide binds with water?

• Oxyhemoglobin

• Bicarbonate

• Carbamino hemoglobin

• Carbonic acid

What happens to carbon dioxide in the lungs?

• It is stored in the alveoli

• It binds with hemoglobin

• It is expelled from the body

• It is converted to oxygen

Which form of carbon dioxide is expelled during expiration?

• Carbamino hemoglobin

• Dissolved gas

• Carbonic acid

• Bicarbonate ions

What is the role of bicarbonate ions in the blood?

• To regulate blood pH

• To bind with hemoglobin

• To store energy

• To transport oxygen