Disorders Of Respiratory System In Humans,,,,
lymph glands at the hilum or root of the lung causing them to undergo considerable enlargement. Usually the infection in the lung and the regional lymph glands, known collectively as the primary complex, heals spontaneously without the development of any symptoms, but occasionally the infection in the lymph glands leads to complications which cause the person concerned to become ill.
The course of the infection depends largely on the age at which it is first acquired. The resistance of infants to the disease is very poor so that infection occurring in the first year of life is always dangerous, but natural immunity gradually improves so that from the age of 5 to 12 any infection usually passes unnoticed. Once adolescence is reached, however, resistance once again diminishes so that infection at this time may be accompanied by ill health.
It must be emphasized that primary infection in childhood is usually a symptomless self-healing disease but occasionally the enlarged hilar lymph glands compress a bronchus, causing collapse of part of the lung, or worse still erode the wall of the bronchus, discharging infected material into the air tubes which then becomes widely disseminated throughout the lungs with the production of a tuberculous broncho pneumonia.
Even more serious is when the glands erode the pulmonary veins, causing infected material to be carried in the blood and disseminated throughout the body. When a large number of virulent tubercle bacilli are released into the circulation, multiple small foci of infection appear around the terminal arterioles in every organ of the body, producing what is known as military tuberculosis.
This term is derived from the appearance of these small foci of infection, which are considered to resemble millet seeds. Before effective chemotherapy was discovered military tuberculosis was invariably fatal, but this type of infection can now readily be brought under control. When the number of tubercle bacilli released into the circulation is smaller infection may be confined to an individual organ such as the brain, causing meningitis, or a joint with resultant arthritis, or the kidney with the production of a pyelonephritis.
lymph glands at the hilum or root of the lung causing them to undergo considerable enlargement. Usually the infection in the lung and the regional lymph glands, known collectively as the primary complex, heals spontaneously without the development of any symptoms, but occasionally the infection in the lymph glands leads to complications which cause the person concerned to become ill.
The course of the infection depends largely on the age at which it is first acquired. The resistance of infants to the disease is very poor so that infection occurring in the first year of life is always dangerous, but natural immunity gradually improves so that from the age of 5 to 12 any infection usually passes unnoticed. Once adolescence is reached, however, resistance once again diminishes so that infection at this time may be accompanied by ill health.
It must be emphasized that primary infection in childhood is usually a symptomless self-healing disease but occasionally the enlarged hilar lymph glands compress a bronchus, causing collapse of part of the lung, or worse still erode the wall of the bronchus, discharging infected material into the air tubes which then becomes widely disseminated throughout the lungs with the production of a tuberculous broncho pneumonia.
Even more serious is when the glands erode the pulmonary veins, causing infected material to be carried in the blood and disseminated throughout the body. When a large number of virulent tubercle bacilli are released into the circulation, multiple small foci of infection appear around the terminal arterioles in every organ of the body, producing what is known as military tuberculosis.
This term is derived from the appearance of these small foci of infection, which are considered to resemble millet seeds. Before effective chemotherapy was discovered military tuberculosis was invariably fatal, but this type of infection can now readily be brought under control. When the number of tubercle bacilli released into the circulation is smaller infection may be confined to an individual organ such as the brain, causing meningitis, or a joint with resultant arthritis, or the kidney with the production of a pyelonephritis.
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