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The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the environment in which it lives and its evolutionary ...
In birds, some temperature control occurs in the respiratory system. [16] Water vapor heats cool air during inhalation in the trachea, and increases its humidity. [16] The resulting evaporative water loss varies greatly and depends on several factors including air sac pressure and the subsequent rate of air flow through the trachea.
Development of the lower respiratory system. Respiratory development in the embryo begins around week 4. Ectodermal tissue from the anterior head region invaginates posteriorly to form olfactory pits, which fuse with endodermal tissue of the developing pharynx. An olfactory pit is one of a pair of structures that will enlarge to become the ...
The breathing of all vertebrates with lungs consists of repetitive cycles of inhalation and exhalation through a highly branched system of tubes or airways which lead from the nose to the alveoli. [4] The number of respiratory cycles per minute is the breathing or respiratory rate, and is one of the four primary vital signs of life. [5]
The respiratory tract is lined by respiratory epithelium or respiratory mucosa, with hair-like projections called cilia that beat rhythmically and carry mucus. This mucociliary clearance is an important defence system against air-borne infection. [ 34 ]
The lungs can be included in the lower respiratory tract or as separate entity and include the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. [3] Adult and pediatric airway anatomy. The respiratory tract can also be divided into a conducting zone and a respiratory zone, based on the distinction of transporting gases or ...
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Inhalation of air, as part of the cycle of breathing, is a vital process for all human life.The process is autonomic (though there are exceptions in some disease states) and does not need conscious control or effort.