LUNGS :
The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic.
The bronchioles eventually end in clusters of microscopic air sacs called alveoli. In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled. Between the alveoli is a thin layer of cells called the interstitium, which contains blood vessels and cells that help support the alveoli.
The lungs are covered by a thin tissue layer called the pleura. The same kind of thin tissue lines the inside of the chest cavity -- also called pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.
Human lung:
In humans, the lungs are located on either side of the heart in the chest, with the left lung sharing the left side of the space with the heart, which sits in an impression called the cardiac notch. The lungs are surrounded by the pleural cavity, a lining of two lubricated layers that allows the negative pressure of breathing to be maintained without friction. The negative inspiratory force in the chest is due to the action of the diaphragm, a muscle below the lungs which separates the chest from the abdomen.
Human lungs can be affected by a variety of diseases. Many respiratory illnesses are because of bacterial or viral infection of the lungs. Inflammation of the lungs is known as pneumonia; inflammation of the pleura surrounding the lungs is known as pleurisy. Lung diseases can arise suddenly, such as a pneumothorax or hemothorax, in which fluid or air is trapped in the pleural cavity and compresses the lung. Diseases can also be chronic, such as emphysema, a common complication of smoking caused by inflammation and the progressive inability of alveoli to expand and contract with respiration. Fibrotic diseases of the lung occur when the lung is inflamed for a long period of time, whether because of a person's occupation (such as Coalworker's pneumoconiosis) or rarer causes, such as a person's medication. Smoking and occupational exposure to harmful substances are also key risk factors for some forms of lung cancer.
The function of human lungs is often measured by lung function tests such as spirometry. These measure how much a person is able to inhale (total lung capacity) or exhale (vital capacity). How well and how quickly a person's lungs expel air helps indicate the health of their lungs and whether, if sick, the disease is obstructive (caused by a difficulty getting air to the alveoli, such as in asthma or choking) or restrictive.
The cone-shaped lungs are sponge-like organs that fill the chest cavity and make up most of the lower respiratory tract. Their most important job is providing oxygen to capillaries so they can oxygenate blood.
Each lung is divided into lobes. The right lung has three, but the left lung has only two, thus allowing room to accommodate the heart.
Together, the lungs’ tissue surface is almost 40 times greater than the body’s outer surface, making the lungs (together) one of the largest organs in the body.
Each lung houses a bronchial tree, which gets its name from the intricate network of air passages that supply the lungs with air. The air-filled sacs in the lungs called alveoli resemble grape clusters. White blood cells known as macrophages, located inside each alveolus, ingest and destroy airborne irritants that enter the lungs. After you exhale, the lungs stay partly inflated because of a fluid called surfactant that is produced by special cells and secreted within the alveoli. Surfactant contains fatty proteins and helps to prevent lung infections.
the air is filled with chemicals, pollutants, dust, pollen, bacteria, and viruses. The billions of microorganisms — bacteria, viruses, and fungi — in the air you breathe can enter the lungs, and they make respiratory infections quite common. Some infections, such as the common cold or sinusitis, affect the upper respiratory tract. Others, such as bronchitis and pneumonia, affect the lower respiratory tract.
Some respiratory disorders are:
Acute bronchitis: This develops suddenly and can occur as a complication of an upper respiratory tract infection, such as a common cold, usually caused by a virus.
Pneumonia: Pneumonia causes the smallest parts of the lungs (bronchioles and alveolar tissue) to become inflamed. Pneumonia can be fatal for elderly people, children, and others with lowered or weakened immune systems.
Asthma: Asthma attacks are caused by constricted airways. Allergic asthma—a type caused by allergens—often develops in childhood. The number of cases of childhood asthma continues to rise.
Tuberculosis: Tuberculosis is a contagious bacterial infection of the lungs. It continues to be a problem for people living in developing countries.
The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic.
The bronchioles eventually end in clusters of microscopic air sacs called alveoli. In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled. Between the alveoli is a thin layer of cells called the interstitium, which contains blood vessels and cells that help support the alveoli.
The lungs are covered by a thin tissue layer called the pleura. The same kind of thin tissue lines the inside of the chest cavity -- also called pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.
Human lung:
In humans, the lungs are located on either side of the heart in the chest, with the left lung sharing the left side of the space with the heart, which sits in an impression called the cardiac notch. The lungs are surrounded by the pleural cavity, a lining of two lubricated layers that allows the negative pressure of breathing to be maintained without friction. The negative inspiratory force in the chest is due to the action of the diaphragm, a muscle below the lungs which separates the chest from the abdomen.
Human lungs can be affected by a variety of diseases. Many respiratory illnesses are because of bacterial or viral infection of the lungs. Inflammation of the lungs is known as pneumonia; inflammation of the pleura surrounding the lungs is known as pleurisy. Lung diseases can arise suddenly, such as a pneumothorax or hemothorax, in which fluid or air is trapped in the pleural cavity and compresses the lung. Diseases can also be chronic, such as emphysema, a common complication of smoking caused by inflammation and the progressive inability of alveoli to expand and contract with respiration. Fibrotic diseases of the lung occur when the lung is inflamed for a long period of time, whether because of a person's occupation (such as Coalworker's pneumoconiosis) or rarer causes, such as a person's medication. Smoking and occupational exposure to harmful substances are also key risk factors for some forms of lung cancer.
The function of human lungs is often measured by lung function tests such as spirometry. These measure how much a person is able to inhale (total lung capacity) or exhale (vital capacity). How well and how quickly a person's lungs expel air helps indicate the health of their lungs and whether, if sick, the disease is obstructive (caused by a difficulty getting air to the alveoli, such as in asthma or choking) or restrictive.
The cone-shaped lungs are sponge-like organs that fill the chest cavity and make up most of the lower respiratory tract. Their most important job is providing oxygen to capillaries so they can oxygenate blood.
Each lung is divided into lobes. The right lung has three, but the left lung has only two, thus allowing room to accommodate the heart.
Together, the lungs’ tissue surface is almost 40 times greater than the body’s outer surface, making the lungs (together) one of the largest organs in the body.
Each lung houses a bronchial tree, which gets its name from the intricate network of air passages that supply the lungs with air. The air-filled sacs in the lungs called alveoli resemble grape clusters. White blood cells known as macrophages, located inside each alveolus, ingest and destroy airborne irritants that enter the lungs. After you exhale, the lungs stay partly inflated because of a fluid called surfactant that is produced by special cells and secreted within the alveoli. Surfactant contains fatty proteins and helps to prevent lung infections.
the air is filled with chemicals, pollutants, dust, pollen, bacteria, and viruses. The billions of microorganisms — bacteria, viruses, and fungi — in the air you breathe can enter the lungs, and they make respiratory infections quite common. Some infections, such as the common cold or sinusitis, affect the upper respiratory tract. Others, such as bronchitis and pneumonia, affect the lower respiratory tract.
Some respiratory disorders are:
Acute bronchitis: This develops suddenly and can occur as a complication of an upper respiratory tract infection, such as a common cold, usually caused by a virus.
Pneumonia: Pneumonia causes the smallest parts of the lungs (bronchioles and alveolar tissue) to become inflamed. Pneumonia can be fatal for elderly people, children, and others with lowered or weakened immune systems.
Asthma: Asthma attacks are caused by constricted airways. Allergic asthma—a type caused by allergens—often develops in childhood. The number of cases of childhood asthma continues to rise.
Tuberculosis: Tuberculosis is a contagious bacterial infection of the lungs. It continues to be a problem for people living in developing countries.
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