respiratory system

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Related to lower respiratory tract: Lower respiratory tract infection

respiratory system:

see respirationrespiration,
process by which an organism exchanges gases with its environment. The term now refers to the overall process by which oxygen is abstracted from air and is transported to the cells for the oxidation of organic molecules while carbon dioxide (CO2
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.

Respiratory system

The system of organs involved in the acquisition of oxygen and the elimination of carbon dioxide by an organism. The lungs and gills are the two most important structures of vertebrates involved in the phase known as external respiration, or gaseous exchanges, between the blood and environment. Internal respiration refers to the gaseous exchanges which occur between the blood and cells. Certain other structures in some species of vertebrates serve as respiratory organs; among these are the integument or skin of fishes and amphibians. The moist, highly vascular skin of anuran amphibians is important in respiration. Certain species of fish have a vascular rectum which is utilized as a respiratory structure, water being taken in and ejected regularly by the animal. Saclike cloacal structures occur in some aquatic species of turtles. These are vascular and are intermittently filled with, and emptied of, water. It is thought that they may function in respiration. During embryonic life the yolk sac and allantois are important respiratory organs in certain vertebrates. See Yolk sac

Structurally, respiratory organs usually present a vascular surface that is sufficiently extensive to provide an adequate area of absorption for gaseous exchange. This surface is moist and thin enough to allow for the passage of gases.

The shape and volume of the lung, because of its pliability, conforms almost completely to that of its cavity. The lungs are conical; each has an apex and a base, two surfaces, two borders, and a hilum. The apex extends into the superior limit of the thoracic cavity. The base is the diaphragmatic surface. The costal surface may show bulgings into the intercostal spaces. The medial surface has a part lying in the space beside the vertebral column and a part imprinted by the form of structures bulging outward beneath the mediastinal pleura. The cardiac impression is deeper on the left lung because of the position of the heart.

For convenience the lung may be divided into anatomical areas. The bronchial tree branches mainly by dichotomy. The ultimate generations, that is, the respiratory bronchioles, alveolar ducts, and alveoli constitute all of the respiratory portion of the lung. The trachea and extrapulmonary bronchi are kept open by C-shaped bars of hyaline cartilage. When in their branching the bronchi and bronchioles are reduced to a diameter of 1 mm or less, they are then free of cartilage and are called terminal bronchioles. One of the terminal bronchioles enters the apex of a secondary lobule of the lung. These secondary lobules are anatomic units of the lung, whose hexagonal bases rest on the pleura or next to a bronchiole or blood vessel. Finer lines divide the bases of the secondary lobules into smaller areas. These are the bases of primary lobules, each served by a respiratory bronchiole. See Lung, Respiration

The blood supply to the lung is provided by the pulmonary and the bronchial arteries. The nerves which supply the lung are branches of the vagus and of the thoracic sympathetic ganglia 2, 3, and 4. Efferent vagal fibers are bronchoconstrictor and secretory, whereas the afferents are part of the arc for the breathing reflex. Efferent sympathetic fibers are bronchodilators; hence, the use of adrenalin for relief of bronchial spasm resulting from asthma. See Nervous system (vertebrate)

respiratory system

[′res·prə‚tȯr·ē ¦sis·təm]
(anatomy)
The structures and passages involved with the intake, expulsion, and exchange of oxygen and carbon dioxide in the vertebrate body.
References in periodicals archive ?
* Children with Gastroenteritis and Lower respiratory tract infections were included in the study.
Combined amyloidosis of the upper and lower respiratory tract. Respiration 1995;62: 163-6.
Lower respiratory tract infections: current aetiological trends and antibiogram.
Serum procalcitonin level, viral polymerase chain reaction analysis, and lower respiratory tract infection.
For example, the rate of all lower respiratory tract infections with severe hypoxemia--with no requirement for demonstration of RSV infection--was reduced by 46% during the first 90 days of life in the immunized group.
Information on socio-demographic variables including child's age, gender and also symptoms of acute lower respiratory tract infection, such as the presence and duration of fever associated with chills, cough, nasal discharge, breathlessness or fast breathing and abdominal pain was taken.
The knowledge of etiology of pathogens in patients of lower respiratory tract infections will be helpful for the empirical drug choice 19.
Therefore, the possibility of disease progression in the lower respiratory tract should be considered even if the airway was uneventfully managed during a recent general anesthetic procedure in patients with Hunter syndrome, and a smaller tracheal tube should be selected.
Early-life exposure to indoor air pollution or tobacco smoke and lower respiratory tract illness and wheezing in African infants: A longitudinal birth cohort study.
RR-1, https://www.cdc.gov/mmwr/pdf/ rr/rr6001.pdf), on page 8, in the first column, in the second paragraph, in the second sentence, the term "pneumonia" was used rather than "lower respiratory tract complications leading to antibiotic use." The corrected sentence should read, "In a study that combined data from 10 clinical trials, the risk for lower respiratory tract complications leading to antibiotic use among those participants with laboratory-confirmed influenza receiving oseltamivir treatment was approximately 50% lower than among those persons receiving a placebo and 34% lower among patients at risk for complications (p<0.05 for both comparisons) (22)."
Researchers found a link between upper and lower respiratory tract infections and heart attacks caused by blood clots.
A major cause of economic losses, BRD affects the lower respiratory tract / lungs (pneumonia) or upper respiratory tract (rhinitis, tracheitis, bronchitis).

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