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Questions and Answers
What is the typical size of a caseous lesion in pulmonary tuberculosis?
What is the typical size of a caseous lesion in pulmonary tuberculosis?
- 5-7 cm
- 2-3 cm
- 3-5 cm
- 1-2 cm (correct)
What is the fate of tuberculosis when it leads to localized spread?
What is the fate of tuberculosis when it leads to localized spread?
- It can cause TB Pleurisy (correct)
- It results in lymphangitis
- It can produce miliary tuberculosis
- It leads to tuberculous bronchopneumonia
Which characteristic is true regarding the lesions of miliary tuberculosis?
Which characteristic is true regarding the lesions of miliary tuberculosis?
- They appear as poorly developed tubercles (correct)
- They are typically surrounded by congested tissue
- They are large and irregularly shaped
- They contain abundant giant cells
Where are tubercles typically located in cases of pulmonary TB?
Where are tubercles typically located in cases of pulmonary TB?
Which of the following describes the appearance of tubercles in tuberculosis?
Which of the following describes the appearance of tubercles in tuberculosis?
What typically occurs with good immunity regarding apical lesions in tuberculosis?
What typically occurs with good immunity regarding apical lesions in tuberculosis?
In which form of tuberculosis is spread through natural passages more rapid and easier?
In which form of tuberculosis is spread through natural passages more rapid and easier?
What characterizes the proliferative reaction in secondary tuberculosis as opposed to primary tuberculosis?
What characterizes the proliferative reaction in secondary tuberculosis as opposed to primary tuberculosis?
Which of the following is NOT a predisposing factor for tuberculosis?
Which of the following is NOT a predisposing factor for tuberculosis?
What is a potential result of localized tuberculous reaction in an organ?
What is a potential result of localized tuberculous reaction in an organ?
What happens to isolated organ tuberculosis when a patient’s immunity is lowered?
What happens to isolated organ tuberculosis when a patient’s immunity is lowered?
What type of organism primarily causes tuberculosis?
What type of organism primarily causes tuberculosis?
In which site does primary tuberculosis commonly occur?
In which site does primary tuberculosis commonly occur?
Which method is NOT used for the transmission of tuberculosis?
Which method is NOT used for the transmission of tuberculosis?
What percentage of infected persons typically develop significant disease from tuberculosis?
What percentage of infected persons typically develop significant disease from tuberculosis?
What is a characteristic of Mycobacterium tuberculosis bacilli?
What is a characteristic of Mycobacterium tuberculosis bacilli?
Which personal factor is associated with a higher risk of developing tuberculosis?
Which personal factor is associated with a higher risk of developing tuberculosis?
Which component is NOT part of the structure of tuberculosis?
Which component is NOT part of the structure of tuberculosis?
What is the role of interferon gamma (INFy) in the immune response against bacilli?
What is the role of interferon gamma (INFy) in the immune response against bacilli?
What characteristic features are associated with Langhans giant cells?
What characteristic features are associated with Langhans giant cells?
Which factor is primarily responsible for increased blood flow to an area of inflammation?
Which factor is primarily responsible for increased blood flow to an area of inflammation?
What happens after 2-3 weeks in the reaction of tubercle formation?
What happens after 2-3 weeks in the reaction of tubercle formation?
Which of the following describes the cellular response surrounding a caseating tubercle?
Which of the following describes the cellular response surrounding a caseating tubercle?
What structural changes characterize an epithelioid cell?
What structural changes characterize an epithelioid cell?
What is the result of fibroblast activity in the context of tubercle formation?
What is the result of fibroblast activity in the context of tubercle formation?
How does the macrophage's response to ingesting bacilli lead to granuloma formation?
How does the macrophage's response to ingesting bacilli lead to granuloma formation?
What characterizes a pyemic abscess in tuberculosis?
What characterizes a pyemic abscess in tuberculosis?
Which of the following sites is NOT commonly affected by miliary tuberculosis?
Which of the following sites is NOT commonly affected by miliary tuberculosis?
What is the fate of tuberculosis infection in the case of a progressive lesion?
What is the fate of tuberculosis infection in the case of a progressive lesion?
How does miliary tuberculosis spread?
How does miliary tuberculosis spread?
What is the central feature in the pathological examination of a tuberculous granuloma?
What is the central feature in the pathological examination of a tuberculous granuloma?
What is a significant consequence of local tissue destruction from tuberculosis?
What is a significant consequence of local tissue destruction from tuberculosis?
Which statement about tuberculosis is true?
Which statement about tuberculosis is true?
Which complication is associated with pulmonary tuberculosis?
Which complication is associated with pulmonary tuberculosis?
What is the fate of tuberculosis infection if it leads to miliary tuberculosis?
What is the fate of tuberculosis infection if it leads to miliary tuberculosis?
Which feature distinguishes tubercles in miliary tuberculosis from other types?
Which feature distinguishes tubercles in miliary tuberculosis from other types?
What characterizes the lymphangitis associated with tuberculosis?
What characterizes the lymphangitis associated with tuberculosis?
Which type of lesion is classically found in primary pulmonary tuberculosis?
Which type of lesion is classically found in primary pulmonary tuberculosis?
What is a common consequence of tuberculous lymphadenitis?
What is a common consequence of tuberculous lymphadenitis?
What is the nature of caseating lesions in tuberculosis when they reach a larger size?
What is the nature of caseating lesions in tuberculosis when they reach a larger size?
What distinguishes the spread of secondary tuberculosis from that of primary tuberculosis?
What distinguishes the spread of secondary tuberculosis from that of primary tuberculosis?
Which characteristic is true for the tissue reaction in primary tuberculosis?
Which characteristic is true for the tissue reaction in primary tuberculosis?
Which of the following best describes the type of organisms that cause tuberculosis?
Which of the following best describes the type of organisms that cause tuberculosis?
In cases of latent tuberculosis, what occurs following a decrease in the host’s immunity?
In cases of latent tuberculosis, what occurs following a decrease in the host’s immunity?
What is the primary means through which tuberculosis infection is generally acquired?
What is the primary means through which tuberculosis infection is generally acquired?
Which of the following statements correctly describes the nature of blood spread in tuberculosis?
Which of the following statements correctly describes the nature of blood spread in tuberculosis?
Which personal factor is specifically associated with a higher risk of tuberculosis infection?
Which personal factor is specifically associated with a higher risk of tuberculosis infection?
In the context of tuberculosis, the term 'granuloma' primarily refers to which of the following?
In the context of tuberculosis, the term 'granuloma' primarily refers to which of the following?
What role do macrophages play in the initial response to tuberculosis infection?
What role do macrophages play in the initial response to tuberculosis infection?
Which environmental factor is associated with an increased risk of contracting tuberculosis?
Which environmental factor is associated with an increased risk of contracting tuberculosis?
Which type of tuberculosis is caused by ingestion rather than inhalation?
Which type of tuberculosis is caused by ingestion rather than inhalation?
What percentage of individuals infected with tuberculosis are expected to develop significant disease?
What percentage of individuals infected with tuberculosis are expected to develop significant disease?
What characterizes the site of infection in miliary tuberculosis?
What characterizes the site of infection in miliary tuberculosis?
Which of the following best describes the feature of a pyemic abscess?
Which of the following best describes the feature of a pyemic abscess?
What occurs in cases of progressive lesions in tuberculosis?
What occurs in cases of progressive lesions in tuberculosis?
Which statement accurately describes the fate of tuberculosis when accompanied by significant caseation?
Which statement accurately describes the fate of tuberculosis when accompanied by significant caseation?
In the context of tuberculous lesions, what does the term 'Assmann focus' refer to?
In the context of tuberculous lesions, what does the term 'Assmann focus' refer to?
What pathological change is commonly seen in advanced pulmonary tuberculosis?
What pathological change is commonly seen in advanced pulmonary tuberculosis?
What complication may arise if an apical tuberculous lesion connects to the pleura?
What complication may arise if an apical tuberculous lesion connects to the pleura?
Which of the following correctly describes the lesions seen in cases of miliary TB?
Which of the following correctly describes the lesions seen in cases of miliary TB?
What is the primary function of interferon gamma (INFy) in the immune response against bacilli?
What is the primary function of interferon gamma (INFy) in the immune response against bacilli?
Which type of cell is formed by the fusion of multiple epithelioid cells in tuberculosis?
Which type of cell is formed by the fusion of multiple epithelioid cells in tuberculosis?
What indicates the onset of central caseation in a tubercle?
What indicates the onset of central caseation in a tubercle?
What cellular component is primarily responsible for encircling the tubercle, leading to fibrosis?
What cellular component is primarily responsible for encircling the tubercle, leading to fibrosis?
Which type of immune cell is primarily attracted to the area of infection by tumor necrotizing factor (TNF-α)?
Which type of immune cell is primarily attracted to the area of infection by tumor necrotizing factor (TNF-α)?
What is the appearance of caseating material in a tubercle typically described as?
What is the appearance of caseating material in a tubercle typically described as?
What occurs to macrophages once they engulf the lipid portion of bacilli?
What occurs to macrophages once they engulf the lipid portion of bacilli?
What is a classic characteristic of Langhans giant cells in tuberculosis?
What is a classic characteristic of Langhans giant cells in tuberculosis?
Flashcards
Tuberculosis (TB)
Tuberculosis (TB)
A chronic infectious disease causing granulomas in various body systems, primarily lungs.
Predisposing factors of TB
Predisposing factors of TB
Factors increasing the risk of getting TB, such as low socioeconomic status, bad hygiene, contact with TB patients, and overcrowding.
TB bacteria characteristics
TB bacteria characteristics
TB bacteria are aerobic, acid-fast, non-motile, and do not produce exotoxins; they are carried by macrophages.
TB bacteria structure
TB bacteria structure
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Types of TB bacteria
Types of TB bacteria
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TB infection method
TB infection method
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Primary complex site
Primary complex site
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Tubercle formation
Tubercle formation
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Macrophage IL-12 release
Macrophage IL-12 release
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Helper T lymphocyte response
Helper T lymphocyte response
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Interferon-gamma (INFγ) function
Interferon-gamma (INFγ) function
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TNF-α function
TNF-α function
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Macrophage transformation
Macrophage transformation
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Langhans giant cells
Langhans giant cells
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Tubercle caseation
Tubercle caseation
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Pulmonary TB Site
Pulmonary TB Site
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Ghon's Focus
Ghon's Focus
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TB Lymphangitis
TB Lymphangitis
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Miliary Tuberculosis
Miliary Tuberculosis
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Miliary TB Spleen
Miliary TB Spleen
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What is a tuberculoma?
What is a tuberculoma?
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Where can a tuberculoma form?
Where can a tuberculoma form?
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What happens in primary TB healing?
What happens in primary TB healing?
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How is TB spread through the body?
How is TB spread through the body?
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What is the difference between primary and secondary TB?
What is the difference between primary and secondary TB?
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Pyemic abscess
Pyemic abscess
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Miliary TB
Miliary TB
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Tuberculosis organism
Tuberculosis organism
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Miliary TB sites
Miliary TB sites
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TB organism in tissue
TB organism in tissue
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TB progression
TB progression
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Tubercle formation (M/E)
Tubercle formation (M/E)
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TB outcomes
TB outcomes
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Primary TB infection
Primary TB infection
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What causes a tubercle to form?
What causes a tubercle to form?
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What is caseation?
What is caseation?
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How does TB spread?
How does TB spread?
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What happens during latent TB infection?
What happens during latent TB infection?
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What are the risk factors for developing TB?
What are the risk factors for developing TB?
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What are the symptoms of active TB?
What are the symptoms of active TB?
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Miliary TB in the Spleen
Miliary TB in the Spleen
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What are the Bad Fates of a Ghon's Focus?
What are the Bad Fates of a Ghon's Focus?
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What does IL-12 activate?
What does IL-12 activate?
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Interferon-gamma (INFγ) role
Interferon-gamma (INFγ) role
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Epithelioid cell formation
Epithelioid cell formation
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Langhans giant cell formation
Langhans giant cell formation
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Tubercle development
Tubercle development
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Primary TB healing
Primary TB healing
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TB spread
TB spread
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Primary vs. Secondary TB
Primary vs. Secondary TB
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What is the difference between Pyemic Abscess and Miliary TB?
What is the difference between Pyemic Abscess and Miliary TB?
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What is the 'Assmann Focus'?
What is the 'Assmann Focus'?
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What are the complications of progressive TB lesions?
What are the complications of progressive TB lesions?
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What is reactive systemic amyloidosis?
What is reactive systemic amyloidosis?
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What is pulmonary hypertension?
What is pulmonary hypertension?
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What is Cor Pulmonale?
What is Cor Pulmonale?
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Study Notes
Tuberculosis
- Tuberculosis (TB) is a chronic, infective granuloma primarily affecting the lungs, but potentially affecting other body systems.
- Environmental factors like low socioeconomic status, poor hygiene, contact with TB patients, overcrowding, and pollution increase susceptibility.
- Personal factors such as race (more prevalent in African Americans), malnutrition, debilitating illnesses, and immune deficiency increase the risk.
- TB bacilli are aerobic, acid-fast, non-motile, do not produce exotoxins, and are carried by macrophages.
- TB bacilli contain carbohydrates, lipids, and proteins, like tuberculoprotein (PPD).
- Two main types of TB exist: human, caused by inhalation, and bovine, caused by ingestion.
Tuberculosis Pathogenesis
-
Primary Pulmonary Tuberculosis (0-3 weeks):
- Mycobacteria proliferate unchecked.
- Macrophages engulf mycobacteria but can't kill them.
- Macrophage activation and resultant granuloma formation occurs.
- This can lead to the development of focal areas of necrosis, known as caseous necrosis.
- The ensuing inflammation creates a tubercle.
-
Tubercle Formation:
- Formation of Epithelioid cell granulomas(cells with distinct cell borders).
- Formation of giant cells (e.g. langhans cell).
- Proliferation of fibroblasts (collagen production).
-
Primary Pulmonary Tuberculosis ( > 3 weeks):
- Inflammation continues and macrophage activation leads to excessive granuloma formation.
- IL-12 and IFN-y stimulate Th1 and T cells.
- TNF-alpha is responsible for blood flow to the affected area.
- Monocytes are recruited
- Formation of a caseous granuloma
-
Types of Tuberculous Reactions:
- Type IV Hypersensitivity: Inflammatory reaction in response to prior exposure.
- No prior exposure: inflammatory reaction in response to initial encounter.
Primary Tuberculosis (Childhood Type)
- Incidence: Occurs in younger, non-immunized individuals; exogenous source of infection.
- Methods of Infection: inhalation, ingestion, direct contact. Methods of Infection:Inhalation, Ingestion, Direct contact
- Site of Primary Complex: Lungs, Tonsils, Skin, Intestine, Nose (less common).
- Proliferative Reaction(Tubercle formation): bacilli are taken in by macrophages, organism multiply in macrophages.
- Helper T cells secrete Interferon Gamma (IFN-γ).
- Cellular reaction: engulfment of lipid part of bacilli and macrophage to epithelioid cell transformation.
- Cell fusion to create Langhans giant cells.
- Tubercle formation: fibroblast encircles the tubercle, forming a firm tubercle.
- Caseation: After 2-3weeks, central caseation develops in the centre of tubercle.
Microscopic Evaluation of Tuberculosis (N/E and M/E)
- N/E (Normal Examination): Tubercle is visible (1-3mm in size), with a central yellow area (caseation) and a grey periphery.
- M/E (Microscopic Examination): Caseating material is observed in the centre, surrounded by epithelioid cells, macrophages, and multinucleated giant cells (often Langhans giant cells).
Pulmonary Tuberculosis
- Pulmonary TB is a common site of TB infection.
- A small caseating lesion (1-2 cm) is found beneath the pleura, typically in the lower part of the upper lobe or upper middle lobe.
- TB Lymphangitis: Inflammation of lymphatic vessels.
- TB Lymphadenitis: Inflammation of lymph nodes.
Primary Tuberculosis Fate
-
Possible Outcomes: Good fate (healing) or bad fate (spread).
-
Local Spread: Can cause pleurisy (inflammation of the pleura).
-
Lymphatic Spread: Spread to peri- and paratracheal lymph nodes, and the mediastinum
-
Blood Spread: Dissemination as miliary tuberculosis.
-
Natural Spread: development of tuberculous bronchopneumonia and pneumonia.
Miliary Tuberculosis
- Lesions appear as multiple, small, uniform tubercles (3mm) scattered throughout the tissues, separated from each other, not surrounded by congestion.
- Microscopic examination shows tubercles related to blood vessels, with poorly developed structures, central necrosis, and absence of giant cells.
Pyemic Abscess
- Caused by pyemia (septic blood flow).
- Formation of many small, acute abscesses in tissues, especially blood vessel areas.
- Areas are rounded, with hyperemic zones surrounding the abscesses.
Secondary Pulmonary Tuberculosis
- Acquired from reactivation of a healed primary complex or exogenously.
- Age of Onset: Adults.
- Site of involvement: Kidneys, suprarenal glands, fallopian tubes, epididymis, brain, meninges, bones, and joints.
- Extensive caseation due to hypersensitivity reaction.
Tuberculoma
- Localized collection of caseating tuberculous reaction surrounded by fibrous tissue.
- May reach large size, potentially mistaken for a tumor.
- Can affect any organ, including the lungs, kidneys, and brain.
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