The mouth and nose admit and expel air from the environment for respiration. The nose contains nostrils or nares that allow for oxygen and CO2 to move through. They both connects to phalynx then larnyx which leads to...
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The trachea, otherwise known as the windpipe, lies in the throat superficial to the esophagus. It serves as a passage for air to travel through to the lungs and back out the opposite direction to the nose or mouth. It is lined with mucus and cilia to trap foreign particles. It separates into...
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The main bronchus (left and right) lead to each lung. They then split even further, from primary to secondary to tertiary to bronchioles. Eventually each bronchiole tapers off into alveoli sacs where the actual gas exchange occurs.
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The lungs are two large organs located near the backbone on either side of the heart. They have large surface areas to contain all of the alveoli. The walls are covered by a thin tissue called pleura to act as a lubricant when they expand and contract with each breath.
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The diaphragm is located in the thoracic cavity. It is a dome-shaped sheet of muscle underneath the lungs. When it contracts the cage around the lungs expands, pulling air into the open space (inhaling). When it expands the space shrinks forcing air out (exhaling).
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