An introduction to the respiratory system
Introduction to respiratory system ppt
These responses cause air to be expelled forcefully from the trachea or nose , respectively. Image credit: Ross Toro, Livescience contributor Respiratory system diseases Diseases and conditions of the respiratory system fall into two categories: Infections, such as influenza , bacterial pneumonia and enterovirus respiratory virus, and chronic diseases, such as asthma and chronic obstructive pulmonary disease COPD. These signs and symptoms may be worse when a person is exposed to their triggers, which can include air pollution , tobacco smoke, factory fumes, cleaning solvents, infections, pollens, foods, cold air, exercise, chemicals and medications. In a normal human lung all the alveoli together contain about 3 liters of alveolar air. Breathing ceases during this maneuver. The bronchial tubes are lined with tiny hairs called cilia that move back and forth, carrying mucus up and out. At the same time, venous blood returning from the various body tissues is pumped into the lungs by the right ventricle of the heart. During exhalation, the diaphragm expands and compresses the lungs, forcing air out.
The contracting diaphragm pushes the abdominal organs downwards. The lungs activate one hormone.
Thirdly, the surface tension of the curved watery layer lining the alveoli tends to draw water from the lung tissues into the alveoli.
Mucus is a sticky fluid that collects dust, germs and other matter that has invaded the lungs and is what we expel when we sneeze and cough. Image credit: Shutterstock COPDsometimes called chronic bronchitis or emphysema, is a chronic and progressive disease where the air flow in and out of the lungs decreases, making it harder to breathe.
Respiratory system definition
The surface tension of a watery surface the water-air interface tends to make that surface shrink. Thirdly, the surface tension of the curved watery layer lining the alveoli tends to draw water from the lung tissues into the alveoli. The converse happens when the carbon dioxide tension falls, or, again to a lesser extent, the oxygen tension rises: the rate and depth of breathing are reduced till blood gas normality is restored. Describes the central nervous system initiation of breathing and the innervation of the respiratory muscles. In dry air the partial pressure of O2 at sea level is During heavy breathing, exhalation is caused by relaxation of all the muscles of inhalation. During exhalation, the diaphragm expands and compresses the lungs, forcing air out. But now, the abdominal muscles, instead of remaining relaxed as they do at rest , contract forcibly pulling the lower edges of the rib cage downwards front and sides Fig. Mucus is a sticky fluid that collects dust, germs and other matter that has invaded the lungs and is what we expel when we sneeze and cough. The particular action illustrated here is called the pump handle movement of the rib cage.
It also regulates inflammatory responses and interacts with the adaptive immune response. The human body needs oxygen to sustain itself.
In dry air the partial pressure of O2 at sea level is It also helps to regulate pH of the blood. Over time, the airways in the lungs become inflamed and thicken, making it harder to get rid of waste carbon dioxide, according to the American Lung Association.
In addition the " accessory muscles of inhalation " exaggerate the actions of the intercostal muscles Fig. Prevention of alveolar collapse Main article: Pulmonary surfactant The lungs make a surfactanta surface-active lipoprotein complex phospholipoprotein formed by type II alveolar cells.
They also release a variety of substances that enter the systemic arterial blood, and they remove other substances from the systemic venous blood that reach them via the pulmonary artery.
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