Primary Tubercle (Ghon Tubercle):
When an individual with no previous exposure to tuberclosis inhale a sufficient number of tubercle bacilli into the alveoli, tuberculosis infection occurs. Inflammation occurs within the parenchyma of the lungs. Body counteracts the infection with the natural body defenses. Lymph nodes in the hilar region of the lung become enlarged as they filter drainage form the infected site. The inflammatroy process and cellular reaction produce a small, firm white nodule called the primary tubercle.
Calcifid Nodule or Chon Tubercle:
The center of the primary tubercles contains tubercle bacilli. Cells gather around the center, and usually the outer portion becomes fibrosed. As blood vessels get compressed interfering with nutrition of the tubercle, necrosis occurs at the center.
The area becomes walled off by fibrotic tissue around the outside, and the center gradually becomes soft and cheesy in consistency. This process is known as caseation necrosis. This material may become calcified (Ghon tubercle). Most people who are exposed to tuberculosis and develop infection do not have active tuberculosis. X-ray shows the calcified nodule. The hilar lymph nodes and a Ghon tubercle seen is X-ray is referred as the primary complex. Person who have primary complex will show positive result inobatin test. However a nurse needs to explain to the clients that a positive tuberculin test does not mean that helshe has tuberculosis. Body's reaction to the organism. A person who has been unless with tubercle bacilli harbours the organism for the remainder of he person's life unless he or she has received prophylactic isonizid. When a person is under physical or emotional stress, the bacilli lying dormant in the lungs become active.