Pulmonary respiratory movement morphology

(1) In the figure, ① glass tube represents trachea, ③ balloon represents lung, ② thoracic cavity and ④ rubber membrane represents diaphragm.

(2) Figure 2 shows inhalation. When inhaling, the diaphragm and intercostal muscle contract, which increases the diameter of the chest cavity, expands the volume of the chest cavity, and expands the lungs, resulting in a decrease in lung pressure, which is less than the external atmospheric pressure. External air enters the lungs, forming active inspiratory movement.

(3) The contraction and relaxation of respiratory muscles make the chest expand and contract regularly, which is called respiratory movement, including inhalation and exhalation. The human body realizes the gas exchange between the lungs and the outside world through inhalation and exhalation.

So, the answer is: (1) trachea; Lung;

(2) contraction; Inhale;

(3) the outside world