Podcast
Questions and Answers
What is the primary cause of tuberculosis?
What is the primary cause of tuberculosis?
What type of organism is Mycobacterium tuberculosis?
What type of organism is Mycobacterium tuberculosis?
What is the name of the stain used to identify Mycobacterium tuberculosis?
What is the name of the stain used to identify Mycobacterium tuberculosis?
During the first 3 weeks after exposure, what happens to the tubercle bacilli?
During the first 3 weeks after exposure, what happens to the tubercle bacilli?
Signup and view all the answers
What type of hypersensitivity reaction occurs in the formation of granuloma?
What type of hypersensitivity reaction occurs in the formation of granuloma?
Signup and view all the answers
What is the name of the reaction that occurs in people with low immunity?
What is the name of the reaction that occurs in people with low immunity?
Signup and view all the answers
What is the main component of the central core of Mycobacterium tuberculosis?
What is the main component of the central core of Mycobacterium tuberculosis?
Signup and view all the answers
What is the term for the death of cells in a granuloma?
What is the term for the death of cells in a granuloma?
Signup and view all the answers
What is Ghon's complex composed of?
What is Ghon's complex composed of?
Signup and view all the answers
What is the main difference between primary and secondary tuberculosis?
What is the main difference between primary and secondary tuberculosis?
Signup and view all the answers
What is the characteristic feature of chronic fibrocaseous pulmonary TB?
What is the characteristic feature of chronic fibrocaseous pulmonary TB?
Signup and view all the answers
What is the most accurate test for diagnosing tuberculosis?
What is the most accurate test for diagnosing tuberculosis?
Signup and view all the answers
What is the primary site of infection in primary tuberculosis?
What is the primary site of infection in primary tuberculosis?
Signup and view all the answers
What is the characteristic feature of lymphadenitis in primary tuberculosis?
What is the characteristic feature of lymphadenitis in primary tuberculosis?
Signup and view all the answers
What is the characteristic feature of tissue reaction in secondary tuberculosis?
What is the characteristic feature of tissue reaction in secondary tuberculosis?
Signup and view all the answers
What is the characteristic feature of tissue destruction in secondary tuberculosis?
What is the characteristic feature of tissue destruction in secondary tuberculosis?
Signup and view all the answers
What type of organs are commonly affected by exudative tissue reaction?
What type of organs are commonly affected by exudative tissue reaction?
Signup and view all the answers
Which of the following is a characteristic of high immunity in tuberculosis?
Which of the following is a characteristic of high immunity in tuberculosis?
Signup and view all the answers
What is the result of direct spread of tuberculosis to surrounding tissues?
What is the result of direct spread of tuberculosis to surrounding tissues?
Signup and view all the answers
What is a common cause of reactivation of tuberculosis?
What is a common cause of reactivation of tuberculosis?
Signup and view all the answers
What is the term for the spread of tuberculosis to many organs through the bloodstream?
What is the term for the spread of tuberculosis to many organs through the bloodstream?
Signup and view all the answers
What is the term for the combination of a Ghon's focus and lymphadenitis?
What is the term for the combination of a Ghon's focus and lymphadenitis?
Signup and view all the answers
What is the term for the initial lesion of primary pulmonary tuberculosis?
What is the term for the initial lesion of primary pulmonary tuberculosis?
Signup and view all the answers
What is the result of the immune system's attempt to contain the tuberculosis infection?
What is the result of the immune system's attempt to contain the tuberculosis infection?
Signup and view all the answers
Study Notes
Tuberculosis
- Chronic infective granulomatous inflammation caused by tubercle bacilli.
- Etiology: low standard of nutrition and housing, low natural resistance.
Mycobacterium Tuberculosis
- There are two types: human and bovine.
- Aerobic, non-motile organism which can be killed by pasteurization.
- Weak gram positive, stained with Ziehl-Neelson stain.
- Structure: central core of protein (tuberculoprotein), polysaccharide fraction, and lipid capsule.
Methods of Infection
- Infection occurs through macrophages by endocytosis, replication within the phagosome, and blocking fusion of phagosome to lysosome.
- Bacteraemia and seeding of multiple sites occur, and most people are asymptomatic.
Pathogenesis
- About 3 weeks after infection, tubercle bacilli are drained to lymph nodes and presented to T cells, which differentiate to T-helper 1 cells that activate macrophages to kill bacteria.
- Type IV hypersensitivity reaction is developed, leading to the formation of granuloma and caseous necrosis.
- Caseation necrosis is due to hypersensitivity reaction and endarteritis obliterans.
TB Caseating Granuloma
- Morphology: cellular reaction (tubercle formation) or exudative reaction (serous membranes).
- Immunity: high immunity results in solid organs, lungs, and cellular tissue reaction; low immunity results in serous sacs, lungs, and exudative tissue reaction.
Fate of the Tubercle
- High immunity: small lesion, totally replaced by fibrosis, and bacteria may remain as a latent infection.
- Low immunity: large caseous lesion, surrounded by fibrosis, and bacteria may spread through blood, lymphatic, or direct spread.
Reactivation and Spread
- Reactivation leads to secondary pulmonary tuberculosis due to lowered immunity.
- Spread can occur through blood, lymphatic, or direct spread, leading to miliary tuberculosis or isolated organ tuberculosis.
Primary Pulmonary TB
- Mode of transmission: primary pulmonary complex (Ghon’s complex).
- Ghon’s focus: small area (1 cm), subpleural, lower part of upper lobe or upper part of lower lobe, formed of coalescent caseating tubercles.
Secondary Pulmonary T.B
- Etiology: reactivation or re-infection.
- Pathogenesis: preexisting hypersensitivity induces rapid and marked tissue response, leading to rapid localization of the disease with less lymph node involvement.
- Course: marked caseation and destruction with extrusion of the caseous material into bronchial tree lead to cavitations and dissemination of infection.
Diagnosis of Tuberculosis
- History of contact with tuberculous patient.
- Toxic manifestation.
- Productive cough, pleuritic pain, hemoptysis.
- Tuberculin test.
- Biopsy: characteristic but not pathognomonic granuloma.
- Identification of TB bacilli (sputum culture, PCR) is the most accurate test for diagnosis.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the topic of tuberculosis, a chronic infectious disease caused by Mycobacterium tuberculosis. It discusses the etiology, predisposing factors, and pathogenic organism of tuberculosis.
