EMBRYOLOGY
RESPIRATORY SYSTEM
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Diaphragm moves up
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Ribs move in
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Ribs move out
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Diaphragm contracts
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Creates larger pressure in thoracic cavity
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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: -The diaphragm, a dome-shaped sheet of muscle that separates the chest cavity from the abdomen, is the most important muscle used for breathing in (called inhalation or inspiration). The diaphragm is attached to the base of the sternum, the lower parts of the rib cage, and the spine.
Detailed explanation-3: -Overview. The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges.
Detailed explanation-4: -Although it fluctuates during inspiration and expiration, intrapleural pressure remains approximately –4 mm Hg throughout the breathing cycle. Competing forces within the thorax cause the formation of the negative intrapleural pressure.