Respiratory System

Air moves into the lungs because:

• the gas pressure in the lungs becomes lower than the outside pressure as the

• contraction of the diaphragm decreases the volume of the pleural cavity.

• the thorax is muscular.d. the volume of the lungs decreases with inspiration.

• the internal intercostal muscles decrease the thoracic cavity volume.

  a. the gas pressure in the lungs becomes lower than the outside pressure as the diaphragm contracts. Boyle's law states that volume changes lead to pressure changes.

Alveolar ventilation rate is:

• the utilization of oxygen by alveolar cells to support metabolism.

• the movement of air into and out of the alveoli during a particular time.

• the movement of dissolved gases from the alveoli to the blood.

• less than the pulmonary ventilation rate because of dead space.

AVR is ​ (a)   ​

• Breaths per minute

• Cardiopulmonary resuscitation

• Arterial blood gases

• Attention deficit hyperactivity disorder

Hemoglobin has a tendency to release oxygen where:

• partial pressures of oxygen are higher.

• pH is more acidic.c. partial pressures of carbon dioxide are lower.

• temperature is lower.

• pH is more alkaline.

In the alveoli, the partial pressure of oxygen is

• about 104 mmHg.b.

• lower than the PO2 of venous blood.

• much higher than the PO2 of arterial blood.

• the same as the PO2 of venous blood.e. equal to that in the

Answer explanation

The partial pressure of oxygen in the alveoli is ~104 mmHG, which is about 35% less than that of the atmospheric PO2.