explain why air enters or leaves the lungs in these conditions of the chest cavity?

Answer 1

because that is what the definition of "BREATHING" is.

Answer 2

What do you mean "in these condition of the chest cavity"? Is the condition sick or something? Sorry, I'm only 13...

But the air enters and leave the lung due to pressure.. Like when you take a deep breath the pressure of your chest cavity decreases forcing the air in.. When you exhale the pressure of your chest cavity increase forcing all the air out..

When it increase the lungs get squeezed forcing the air out, when it decreases the lungs gets well.. yeah ...

I maybe wrong so take info on other answers.. Or better yet, research for your self..

Answer 3

The atmospheric pressure is a positive pressure, The pressure in the lungs is a negative pressure... so the atmospheric pressure helps push air into the lungs, and the lungs have to work to get the carbon-dioxide out.

...the lower brain stem controls respirations and is part of the ananomic nervious system.

Answer 4

The Respiratory System
The respritory system keeps us alive by oxygenating the blood in our bodies. This animation illustrates how the various pieces of the respiratory system work together.





You breathe in and out anywhere from 15 to 25 times per minute without even thinking about it. When you exercise, your breathing rate goes up -- again, without you thinking about it. You breathe so regularly that it is easy to take your lungs for granted. You can't even stop yourself from breathing if you try!

Your lungs are complex organs, but what they do is take a gas that your body needs to get rid of (carbon dioxide) and exchange it for a gas that your body can use (oxygen). In this article, we will take a close look at how your lungs work and how they keep your body's cells supplied with oxygen and get rid of the carbon dioxide waste. We will explain some of the conditions and diseases that make breathing harder and cause the lungs to fail. We will also explain why you can't hold your breath for a long time and why you cough or hiccup. The respiratory system includes the nose, throat, larynx, trachea, bronchi, and lungs. The function of the respiratory system is to supply the blood with necessary oxygen and to relieve it of the waste product carbon dioxide.

This exchange of oxygen and carbon dioxide occurs in the lungs. Air from the outside enters through the nose, where it is warmed, moistened, and filtered before it passes through the throat and past the larynx (voice box) into the trachea (windpipe). The trachea divides into two main bronchi (the airways connecting the windpipe and the lungs).

Within each lung, the bronchi divide and subdivide, forming progressively smaller passageways called bronchioles. The smallest bronchioles end in small, cup-shaped sacs called alveoli. It is in the alveoli that the exchange of gas takes place. Each alveolus is served by numerous tiny blood vessels called capillaries. Oxygen in the alveolus crosses the thin alveolar and capillary walls to enter the blood, while carbon dioxide passes from the blood through the capillary walls into the alveolus. The oxygen is then carried by the blood to cells throughout the body, and the carbon dioxide is exhaled.

During inhalation and exhalation, the lungs are expanded and contracted by movements of the rib cage and the diaphragm (the large muscle separating the chest and abdominal cavities). During inhalation, the diaphragm contracts. This causes the diaphragm to descend and the chest cavity to expand. At this point, the air pressure inside the chest cavity is less than that of the air outside the body; consequently, air from the outside rushes into the lungs.

During exhalation, the diaphragm relaxes and moves upward, reducing the chest capacity and pushing air out of the lungs. The friction caused by expansion and contraction of the lungs is eased by the pleurae (thin, moist membranes that cover the lungs and line the chest cavity), so that the surfaces of the lungs and chest cavity can move past each other smoothly.


How You Breathe
Your lungs are located within your chest cavity inside the rib cage .They are made of spongy, elastic tissue that stretches and constricts as you breathe. The airways that bring air into the lungs (the trachea and bronchi) are made of smooth muscle and cartilage, allowing the airways to constrict and expand. The lungs and airways bring in fresh, oxygen-enriched air and get rid of waste carbon dioxide made by your cells. They also help in regulating the concentration of hydrogen ion (pH) in your blood.

When you inhale, the diaphragm and intercostal muscles (those are the muscles between your ribs) contract and expand the chest cavity. This expansion lowers the pressure in the chest cavity below the outside air pressure. Air then flows in through the airways (from high pressure to low pressure) and inflates the lungs. When you exhale, the diaphragm and intercostal muscles relax and the chest cavity gets smaller. The decrease in volume of the cavity increases the pressure in the chest cavity above the outside air pressure. Air from the lungs (high pressure) then flows out of the airways to the outside air (low pressure). The cycle then repeats with each breath.

Where the Air Goes
As you breathe air in through your nose or mouth, it goes past the epiglottis and into the trachea. It continues down the trachea through your vocal cords in the larynx until it reaches the bronchi. From the bronchi, air passes into each lung. The air then follows narrower and narrower bronchioles until it reaches the alveoli.

What Happens When the Air Gets There
Within each air sac, the oxygen concentration is high, so oxygen passes or diffuses across the alveolar membrane into the pulmonary capillary. At the beginning of the pulmonary capillary, the hemoglobin in the red blood cells has carbon dioxide bound to it and very little oxygen (Figure 2). The oxygen binds to hemoglobin and the carbon dioxide is released. Carbon dioxide is also released from sodium bicarbonate dissolved in the blood of the pulmonary capillary. The concentration of carbon dioxide is high in the pulmonary capillary, so carbon dioxide leaves the blood and passes across the alveolar membrane into the air sac. This exchange of gases occurs rapidly (fractions of a second). The carbon dioxide then leaves the alveolus when you exhale and the oxygen-enriched blood returns to the heart. Thus, the purpose of breathing is to keep the oxygen concentration high and the carbon dioxide concentration low in the alveoli so this gas exchange can occur!

Answer 5

Collapsed lung? Pneumothorax.

Answer 6

Its called negative pressure breathing ! Be more specific ?

Answer 7

are you a high school student who wants to get the answers to her homework from the internet?