Inhalation: 1. Diaphragm in a state is domed. When it contracts, it and . 2. intercostal muscles contract and pull on ribs - lifted up and out.
After inhalation, the thoracic cavity will decrease in volume
As the the volume of the thoracic cavity increases, air pressure decreases.
If the thoracic cavity has a lower air pressure then...
air moves into the lungs down the pressure gradient
air moves out of the lungs down the pressure gradient
air moves into the lungs up the pressure gradient
air moves out of the lungs up the pressure gradient
Exhalation: 1. Diaphragm and rises. 2. The intercostals relax and internal intercostals . 3. The volume of the thoracic cavity .
As the volume of the thoracic cavity decreases, air pressure decreases.
As the air pressure in the thoracic cavity increases, air is forced out down the pressure gradient.