These substances cause fibrous or scar tissue to form. For example, after the macrophages swallow silica particles, they die and give off toxic substances. The amount of dust and the kinds of particles involved influence how serious the lung injury will be.
Dust particles and dust-containing macrophages collect in the lung tissues, causing injury to the lungs. But if the amount of dust is large, the macrophage system may fail. Particles that evade elimination in the nose or throat tend to settle in the sacs or close to the end of the airways. The most significant reactions of the lung occur in the deepest parts of this organ. If the particle attacks the larger air passages, inflammation of the trachea (tracheitis) or the bronchi (bronchitis) may be seen. For example, irritant dust that settles in the nose may lead to rhinitis, an inflammation of the mucous membrane. The way the respiratory system responds to inhaled particles depends, to a great extent, on where the particle settles. What are the reactions of the lungs to dust? We are not including chemical dusts that cause other acute toxic effects, nor long term effects such as cancer for example. However, in this OSH Answers document, we are only considering dust particles that cause fibrosis or allergic reactions in the lungs. For example, histoplasmosis, psittacosis and Q Fever are diseases that people can get if they breathe in organic that are infected with a certain microorganisms.ĭusts can also come from organic chemicals (e.g., dyes, pesticides). Aside from the vegetable or animal component, organic dusts may also contain fungi or microbes and the toxic substances given off by microbes. These dusts can contain a great number of substances. An example of organic dust is dust that arises from handling grain. Organic dusts originate from plants or animals. Examples of inorganic dusts are silica, asbestos, and coal. Inorganic dusts can come from grinding metals or minerals such as rock or soil. The particles are "inorganic" or "organic," depending on the source of the dust. These proteins attach to particles to neutralize them.ĭusts are tiny solid particles scattered or suspended in the air. The lungs can react to the presence of germ-bearing particles by producing certain proteins. The wavelike motions of the cilia move the macrophages which contain dust to the throat, where they are spat out or swallowed.īesides macrophages, the lungs have another system for the removal of dust. Then the macrophages, in a way which is not well understood, reach the part of the airways that is covered by cilia. Macrophages virtually swallow the particles. These are extremely important for the defense of the lungs. The air sacs are very important because through them, the body receives oxygen and releases carbon dioxide.ĭust that reaches the sacs and the lower part of the airways where there are no cilia is attacked by special cells called macrophages. The air reaches the tiny air sacs (alveoli) in the inner part of the lungs with any dust particles that avoided the defenses in the nose and airways. Tiny hairs called cilia, covering the walls of the air tubes, move the mucus upward and out into the throat, where it is either coughed up and spat out, or swallowed.
The mucus they produce catches most of the dust particles. These tubes are called bronchi and bronchioles. Some of the smaller particles succeed in passing through the nose to reach the windpipe and the dividing air tubes that lead to the lungs. Most large particles are stopped in it, until they are removed mechanically by blowing the nose or sneezing.
When a person breathes in, particles suspended in the air enter the nose, but not all of them reach the lungs.
#Best ste to play regular timecontrol chessess series#
Physical activity recommendations by age.The lungs are protected by a series of defense mechanisms in different regions of the respiratory tract. Includes games, activity sheets, videos, and songs. This graphic explains how 60 minutes of daily moderate-to-vigorous physical activity can benefit a student’s health and directly impact teachers and the community. Infographic: Benefits of school-based physical activity How obesity is defined for children, prevalence, associated factors, and related health consequences.Ĭonfused about portion sizes? Play the CDC’s portion control game! See more about BMI for children and teens. Classroom resources for teachers of grades 4 through 8 to help students make healthier lifestyle choices.Ĭhildren learn why calcium, vitamin D, and bone-strengthening activity are essential.Ĭhild and Teen BMI (Body Mass Index) Calculatorįor children, BMI screens for obesity, but it is not a diagnostic tool.