What is the role of the diaphragm and ribs during exhalation

In a calm state, the exhalation process is a passive process, with the upward lifting of the diaphragm and the contraction of the rib cage helping the lungs to expel the air from the body.

I guess you're a middle school student, taking Biology or Physiology and Hygiene.

That's what the book says.

Needless to say, the role of the diaphragm is definitely contraction.

But the role of the muscles between the ribs cannot simply be said to be contraction or relaxation.

Strictly speaking, the muscles between the ribs are divided into internal and external intercostal muscles, which play a role in the process of exhalation and inhalation.

The external intercostal muscles contract during inspiration to assist in inhalation (by lifting the anterior end of the rib cage).

The internal intercostal muscles contract during exhalation and act by causing the ribs to descend.

c. During inhalation, the intercostal muscles contract, so that the anterior, anterior, left and right diameters of the chest broads increase; The diaphragm contracts and decreases in position, increasing the upper and lower diameters of the broad chest. At this time, the ribs are outward and upward, the chest and lung volume expand, the air pressure in the lungs becomes lower, and air is inhaled.

(1) In the figure, the diaphragm is relaxed, the top of the diaphragm is raised, and the lungs are narrowed, indicating exhalation In the figure, the diaphragm is contracted, the top of the diaphragm is lowered, and the lungs are expanded, indicating inhalation

2) Inspiratory process: When inhaling, the diaphragm and intercostal muscles contract, causing the anterior, left, right, and upper and lower diameters of the chest cavity to increase, the top of the diaphragm to descend, the volume of the thoracic cage to expand, and the lungs to expand, resulting in a decrease in the air pressure in the lungs, which is less than the external atmospheric pressure, and the external gas enters the lungs, forming an active inspiratory movement

So the answer is: 1) b; a

2) shrinkage; Enlarge; Dilate; Decline.

(1) (2) Inspiratory process: during inhalation, the diaphragm and intercostal muscles contract, causing the anterior, left, right, and upper and lower diameters of the thoracic cavity to increase, the top of the diaphragm to descend, the volume of the thoracic cage to expand, and the lungs to expand, resulting in a decrease in the air pressure in the lungs, which is less than the outside atmospheric pressure, and the external gas enters the lungs, forming an active inhalatory movement; When the diaphragm and external intercostal muscles are relaxed, the ribs and sternum return due to their own gravity and elasticity, and the top of the diaphragm rises, resulting in a decrease in thoracic volume and a retraction of the lungs, resulting in an air pressure in the lungs that is greater than the outside air pressure, and the air in the lungs is expelled from the lungs, forming a passive expiratory movement b The diaphragm contractes, the top of the diaphragm descends, and the lungs expand, indicating inhalation

3) Breathing exercise refers to the rhythmic expansion and contraction of the human chest, including the inhalation process and the exhalation process, when inhaling, when the intercostal muscles contract, the ribs move upwards and outwards, so that the anterior and posterior diameter of the chest and the left and right diameters are increased, and at the same time, the diaphragm contractions, the top of the diaphragm descends, so that the upper and lower diameters of the chest cage are increased, so that the volume of the chest increases, and the lungs also expand, the air pressure in the lungs is lower than the outside atmospheric pressure, and the outside air enters the lungs through the respiratory tract to complete the process of inhalation

So the answer is: (1)a;

2）b；（3）b．

From the analysis, it can be seen that;

During inspiration, the external intercostal muscles contract, the ribs are lifted, and the sternum moves upward and outward, increasing the anteroposterior and left and right diameters of the thoracic cage; At the same time, the diaphragm contracts and the top of the diaphragm descends, increasing the upper and lower diameters of the thoracic cage At this time, the thoracic cage expands, the lungs expand, the volume of the lungs increases, the air pressure in the lungs decreases, and the outside air enters the lungs through the respiratory tract to complete the inhalation action

So the answer is: shrinkage; Decline. Above; Outside; Dilate; Below

Breathing exercise refers to the rhythmic expansion and contraction of the human chest, including the inhalation process and the exhalation process, when inhaling, when the intercostal muscles contract, the rib revolt moves upward and outward, so that the anterior and posterior diameter and left and right diameter of the thoracic cage are increased;

At the same time, the diaphragm contractes, the top of the diaphragm descends, so that the upper and lower diameters of the chest cage increase, the volume of the potato-like chest cage increases, and the lungs also expand, the air pressure in the lungs is lower than the outside atmospheric pressure, and the outside air enters the lungs through the respiratory tract, completing the over-inhalation When exhaling, the opposite can be seen that option b is correct

Therefore, choose B

C test question analysis: the muscles involved in the breathing movement mainly include the diaphragm, the muscles between the ribs and other respiratory muscles, when the calm inhalation, the intercostal muscles and the diaphragm contract, causing the chest cavity to increase before and after, left and right, and up and down diameter, the lungs then expand, forming an active inhalation movement, when the external intercostal muscles and diaphragm are relaxed, the ribs and sternum return due to their own gravity and elasticity, as a result, the chest cage shrinks, and the lungs also retract, forming a passive expiratory movement, so choose C.

Breathing exercise refers to the rhythmic expansion and contraction of the human chest, including the inhalation process and the exhalation process, when inhaling, when the intercostal muscles contract, the ribs move upwards and outwards, so that the anterior-posterior diameter and the left and right diameters of the thoracic cage are increased;

At the same time, the diaphragm contracts and the top of the diaphragm descends, so that the upper and lower diameters of the thoracic cage increase, so that the volume of the thoracic cage increases, and the lungs also expand, and the air pressure in the lungs is lower than the outside atmospheric pressure, and the outside air enters the lungs through the respiratory tract, completing the over-inhalation of the inhalation

Therefore, choose B