Why does the chest wall expand?

Inhalation and exhalation: The lungs, chest wall, and diaphragm are all involved in respiration, both (a) inhalation and (b) expiration. During this process, the chest wall expands out and away from the lungs.

Does the chest wall want to expand?

Elastic properties of the chest wall



As can be seen from this diagram, the pressure exerted by the chest wall is generally negative, i.e. the chest wall basically wants to expand to a resting volume which is quite a bit greater than the FRC.

What is chest wall expansion?

Overall Chest Expansion: Take a tape and encircle chest around the level of nipple. Take measurements at the end of deep inspiration and expiration. Normally, a 2-5″ of chest expansion can be observed. Any lung or pleural disease can give rise to a decrease in overall chest expansion.

Why is it important that the chest can expand?

Why is this important? Chest expansion can improve secondarily to rib mobility improvement and as both improve, lung capacity (the amount of air taken into and out of the lungs with one breath) improves.

What must happen for the chest cavity to be expanded?

During inspiration, the diaphragm and external intercostal muscles contract, causing the rib cage to expand and move outward, and expanding the thoracic cavity and lung volume. This creates a lower pressure within the lung than that of the atmosphere, causing air to be drawn into the lungs.

How do I find my chest expansion?


And they should move equally apart. That's outward expansion if you want to do an antral posterior expansion you just lay your two hands the top of the chest ask them to take a deep breath in.

How do you know if chest is symmetrical expansion?

Symmetry of chest expansion:

  1. Have patient seated erect or stand with arms on the side. Stand behind patient. …
  2. Place your hands over upper chest and apex and repeat the process.
  3. Next, stand in front and lay your hands over both apices of the lung and anterior chest and assess chest expansion.


Why do you think the chest expands then relaxes during breathing?

In the same way as in relaxed breathing the expansion of the chest cavity draws air in so the lungs fill up. The relaxation of the chest cavity pushes air out. Muscles can also force the chest cavity to contract even further, pushing even more air out.

When you breathe in your lungs get bigger or smaller?

As you breathe in, your diaphragm contracts and flattens out. This allows it to move down, so your lungs have more room to grow larger as they fill up with air.

When you inhale Does your chest expand because your lungs inflate or do your lungs inflate because your chest expands explain?

Explain. We inhale because the chest expands. Contraction of the respiratory muscles enlarges the thoracic cavity, lowering the intrapulmonary pressure and sucking air down its pressure gradient into the lungs.

What triggers inhalation and exhalation?

When the diaphragm contracts, it moves down towards the abdomen. This movement of the muscles causes the lungs to expand and fill with air, like a bellows (inhalation). Conversely, when the muscles relax, the thoracic cavity gets smaller, the volume of the lungs decreases, and air is expelled (exhalation).

What causes the air pressure in the lungs to increase?

Contraction and relaxation of the diaphragm and intercostals muscles (found between the ribs) cause most of the pressure changes that result in inspiration and expiration. These muscle movements and subsequent pressure changes cause air to either rush in or be forced out of the lungs.