AP BIOLOGY

Detailed explanation-1: -When the lungs inhale, the diaphragm contracts and pulls downward. At the same time, the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the lungs.

Detailed explanation-2: -When you breathe in, or inhale, your diaphragm contracts and moves downward. This increases the space in your chest cavity, and your lungs expand into it. The muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.

Detailed explanation-3: -In addition to helping you breathe, your diaphragm increases pressure inside your abdomen. This helps with other important functions, such as getting rid of your urine (pee) and feces (poop). It helps prevent acid reflux by putting pressure on your esophagus (food tube in your throat).

Detailed explanation-4: -During inhalation, volume increases as a result of contraction of the diaphragm, and pressure decreases (according to Boyle’s Law). This decrease of pressure in the thoracic cavity relative to the environment makes the cavity less than the atmosphere (Figure 2a).

Detailed explanation-5: -When the diaphragm contracts, the volume of the thorax increases, thoracic pressure: decreases and air rushes into the lungs. Quiet inspiration is the function of: the diaphragm and externalcostal.