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Describe the inward forces of elastic recoil, and explain why the lungs do not normally collapse during expiration

Elastic recoil is the recoil fo elastic fibers stretched during inspiration and the pull of the surface tension of alveolar fluid. Intrapleural pressure is always subatmospheric during normal breathing, which tends to pull lungs outward and keep alveolar pressure from equalizing with atmospheric pressure. Surfactant in alveolar fluid decreases surface tension to help prevent collapse

Why is epinephrine injected as treatment for the respiratory signs and symptoms of anaphylaxis

Epinephrine enhances sympathetic activity to dilate airways and decrease airway resistance. which had been elevated by the effects of histamine on the bronchioles. It also raises blood pressure, which enhances oxygen delivery to tissues by increasing flow

Describe and explain the effects of smoking on the functioning of the respiratory system

Nicotine constricts terminal bronchioles to increase airway resistance, as does the increased mucus secretion and swelling of the mucosa. Smoke inhibits the movement of cilia, which allows buildup of substances and microbes normally removed. Over time, smoking leads to destruction of elastic tissue, which decreases compliance, and ultimately to the effects of emphysema

Describe the neural, chemical and physical changes that increase the rate and depth of ventilation during exercise

Anticipation of exercise generates neural input to the limbic system. Sensory input is provided from proprioceptors and motor input is provided from the primary motor cortex. As the partial pressure of oxygen falls due to increased consumption, the partial pressure of carbon dioxide and the temperature increase dur to metabolic activity in muscle fibers. Also, carbon dioxide is added. Themoreceptors sense the changes in partial pressure and notify the medullary center to increase the rate and depth of breathing

In chronic emphysema, some elveoli merge together and some are replaced with fibrous connective tissue. In addition, the bronchioles are often inflamed, and expiratory volume is reduced. Using proper respiratory system terminology, explain at least four reasons why affected individuals will heave problems with ventilation and external respiration

Reduced compliance (reduces ability to increase thoracic volume); increased airway resistance (decreases tidal volume); decreased diffusion due to increased diffusion distance, decreased surface area, and changes in partial pressures of gases (altering gradients).

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