3. TBQ - Breathing in human

Breathing is associated with the ingestion and egestion of waste materialsingestion of food and inspiration of airinspiration and expiration of airdigestion and absorption of food between the atmosphere and the lungs' alveoli. The diaphragm and the intercostal muscles control it. The diaphragm is a  dome-shaped smooth musclecircular shaped smooth muscleclover leaf like smooth muscleconvergent shaped smooth muscle that differentiates the thoracic cavity from the abdominal cavity.

 

During inhalation the diaphragm contracts and descendsdiaphragm relaxes and returns to the dome shapediaphragm contracts and relaxesNone of the above. The sternum and the ribs are pushed up and outwards. The volume of the thoracic cavity thus increases, which creates Negative and positive pressure created inside the lungs positive pressure in the lungsnegative pressure inside the lungsIt won't create any pressure inside the lungs.. Thus the lungs inflate and draw in air from outside the body.

 

During exhalation, the diaphragm relaxes and returns to the dome shape and the sternum and the ribs return to the original positionthe diaphragm contracts and returns to the dome shape and the sternum and the ribs return to the original positionthe diaphragm contracts and descends and the sternum and the ribs are pushed up and outwardsthe diaphragm relaxes and descends and the sternum and the ribs are pushed up and outwards. The volume of the thoracic cavity decreases, which creates a positive pressure in the lungs. Thus the lungs return to the original position, and thus air is expelled from the lungs.