when air moves out of the lungs, the air pressure decreases
decreased
The pressure inside the lungs decreases as the ribcage moves out and up. Air from outside basically gets pushed in by other air molecules due to the pressure gradient (air moves from a high pressure to a low pressure)
inhale:- the air pressure in the lungs decreases and air moves in. exhale:-air pressure in the lungs increases and air moves out.
The muscle is the "diaphragm" muscle. It is located beneath the lungs. When it moves down and away, it creates lower pressure around the lungs, and the air pressure outside the body flows into the lungs. When it moves up and in, it compresses the lungs, increasing the pressure to force the air back out.
The air pressure changes inside and outside the body, breathing takes place.In normal conditions,air moves from high pressure area to low pressure are.
This depends on exhalation or inhalation. If you are exhaling the pressure would be greater inside the lungs than the outside, but if you are inhaling, then the pressure would be greater on the outside than the inside.
Since the volume of the lungs increases, the intrathotacic pressure decreases, and air moves into the lungs.
Your diaphragm moves downward, creating less pressure inside your lungs. Air rushes in. Your lungs then filter the air and extract the oxygen, which is sent through your brochial tubes to your blood vessels, which distrubutes the oxygen around your body.
Inspiration happens when the pressure inside the lungs is lower than the atmospheric pressure (outside) and air rushes into the lungs. Expiration is when the air inside the lungs is higher than the atmospheric pressure and the air rushes out of the lungs. If the intrapleural pressure (pressure within the pleura of the lungs) isn't maintained then the pressure in the lungs can't differentiate between inspiration and expiration and so the lung collapses.
The diaphragm contracts and a vacuum is created inside the thorax. The lungs expand to fill the space created, as reduced air pressure allows air to expand the lungs. The intercostals' muscle contract and lift the ribcage further increasing the thoracic space.
As the diaphragm contracts or retracts, the interior pressure of the lungs changes. As this pressure change occurs, the air pressure outside of the body remains unchanged. The resulting lack of pressure equality forces the air in or out of the lungs to maintain an equilibrium in the body pressure.
The diaphragm. (located beneath the lungs) When it contracts it moves down, thus expanding the volume of the lungs. This causes the pressure in the lungs to decrease and air to flow in to the lungs. (pressure is inversely proportional volume- Boyle's law) This is inhaling. When the diaphragm relaxes it moves back up, decreasing the volume of the lungs and increasing the pressure which forces the air out. This is exhalation.
Pulmonary ventilation or breathing has two phases. Inspiration or inhalation moves air into the lungs and expiration or exhalation moves air out of the lungs. The lungs are enclosed within the thoracic cavity. Thus changes in the shape and size of the thoracic cavity result in changes in the air pressure within that cavity and in the lungs. This difference in air pressure causes the movement of air into the lungs. Air moves from an area where pressure is high to an area where pressure is low. Respiratory muscles are responsible for the changes in the shape of the thoracic cavity that cause the air movements involved in breathing.The abdominal diaphragm is (or should be) the major muscle driving respiration.Source(s):Structure and function of the body