why does air move into the lungs?
Bob Pursley answered this question for you earlier. See you previous post of the same question
To understand why air moves into the lungs, we have to look at the process of breathing.
Breathing, also known as ventilation, is the movement of air into and out of the lungs. It involves a combination of mechanical and physiological processes. The primary muscle responsible for breathing is the diaphragm, a dome-shaped muscle located at the base of the chest cavity.
When we inhale, the diaphragm contracts and moves downward. At the same time, the muscles between our ribs, known as intercostal muscles, contract, causing the ribcage to expand. This expansion increases the volume of the chest cavity, creating a negative pressure.
The negative pressure created in the chest cavity causes air to flow into the lungs. This happens because of the principle of gas exchange, which states that air flows from an area of higher pressure to an area of lower pressure. Our lungs are filled with tiny air sacs called alveoli, which are surrounded by blood vessels known as capillaries. The negative pressure in the lungs causes air to rush in through the airways, passing through the bronchi and bronchioles until it reaches the alveoli.
Once the air reaches the alveoli, oxygen from the inhaled air diffuses across the thin walls of the alveoli and into the surrounding capillaries. At the same time, carbon dioxide, a waste product of cellular metabolism, diffuses out of the capillaries and into the alveoli. This exchange of gases helps oxygenate the bloodstream and remove carbon dioxide.
Overall, air moves into the lungs because of the changes in pressure created by the contraction of the diaphragm and intercostal muscles. This allows for the exchange of oxygen and carbon dioxide, which is essential for cellular respiration and maintaining the body's balance of gases.