The document describes the pathological changes seen in various respiratory tract conditions: - Tuberculosis causes localized lesions in the lungs with tubercle formation that can lead to cavitary lesions and scarring. - Bronchitis shows thickened and inflamed bronchial walls filled with mucus plugs microscopically. - Pneumonia has four stages - congestion, hepatization, grey hepatization, and resolution - characterized by fluid, cells, and fibrin in the alveolar spaces. - Other conditions mentioned include pleural effusion, lung abscess, emphysema, bronchial asthma, and chronic obstructive pulmonary disease. Microscopic features include inflammation, edema, thickening of structures

1. RESPIRATORY
TRACT
CONDITION

2. TUBERCULOSIS

3. PATHOLOGICAL CHANGES
LOCALIZED LESION USUALLY IN THE POSTERIOR SEGMENT OF UPPER LOBE. THE LESION CONSISTS OF
TUBERCULOSIS GRANULOMAS
PRESENCE OF FOCI OF CONSOLIDATION.THE TUBERCLE FORMATION RESULTING IN CAVITARY LESIONS
(ABNORMAL GAS-FILLED SPACES)
PRESENCE OF SCARRING & DYSTROPHIC CALCIFICATIONS (DEPOSITION OF CALCIUM SALT IN DEGENERATED
TISSUES)

6. BRONCHITIS

7. PATHOLOGICAL CHANGES
GROSSLY:
• BRONCHIAL WALL IS THICKENED, HYPEREMIC AND EDEMATOUS.
• PRESENCE OF MUCUS PLUG IN BRONCHI & BRONCHIOLES
MICROSCOPICALLY:
• HYPERTROPHY & HYPERPLASIA OF SUBMUCOSAL GLANDS IN BRONCHIAL AIRWAYS & TRACHEA
• LUMINA OF THE BRONCHI AND BRONCHIOLES MAY CONTAIN MUCUS PLUGS AND PURULENT EXUDATE.

10. PLEURAL EFFUSION

11. PATHOLOGICAL CHANGES
 STIFFNESS OF THE LUNGS AND CHEST WALL.
 PRESENCE OF TRANSUDATES (FLUID BUILDUP CAUSED BY SYSTEMIC CONDITIONS THAT ALTER THE
PRESSURE IN BLOOD VESSELS)
 PRESENCE OF EXUDATES (FLUID BUILD UP CAUSED BY TISSUE LEAKAGE DUE TO INFLAMMATION )
 PRESENCE OF WBC IN PLEURAL FLUID.
 HIGH PLEURAL FLUID

12. PNEUMONIA

13. PNEUMONIA: PATHOLOGICAL CHANGES
LOBAR PNEUMONIA: PATHOLOGICAL PHASES ARE DIVIDED IN 4 SEQUENTIAL PHASES.
1. STAGE OF CONGESTION (INITIAL PHASE; 1-2 DAYS)
GROSSLY:
 THE AFFECTED LOBE OF LUNG IS ENLARGED, HEAVY, DARK, RED & CONGESTED
MICROSCOPICALLY:
 DILATED & CONGESTED ALVEOLAR CAPILLARIES & ALVEOLAR SPACES
 PRESENCE OF PALE FLUID IN AIR SPACES ALONG WITH RBCS, NEUTROPHILS & BACTERIA IN THE
ALVEOLAR FLUID

14. PNEUMONIA: PATHOLOGICAL CHANGES
2. STAGE OF HEPATIZATION (EARLY CONSOLIDATION; 2-4 DAYS)
GROSSLY:
 THE AFFECTED LOBE OF LUNG IS RED, FIRM & CONSOLIDATED
 ON CROSS SECTION OF THE LOBE, LIVER LIKE CONSISTENCY APPEAR, WHICH IS RED-PINK, DRY, GRANULAR WITH
PLEURAL THICKENING
MICROSCOPICALLY:
 EDEMA FLUID IS REPLACED BY FIBRIN STRANDS WITH CELLULAR EXUDATES OF NEUTROPHILS & EXTRAVASTATION
OF RBCS
 LESS PROMINENT ALVEOLAR SEPTA

17. PNEUMONIA: PATHOLOGICAL CHANGES
3. GREY HEPATIZATION (LATE CONSOLIDATION; 4-8 DAYS)
GROSSLY:
 THE AFFECTED LOBE OF LUNG IS FIRM, HEAVY & RED-PINK IN APPEARANCE WITH LIVER LIKE CONSISTENCY
 CHANGE IN COLOR FROM RED-PINK TO GREY OF AFFECTED LOBE
 FIBRINOUS PLEURISY IS PRESENT
MICROSCOPICALLY:
 NEUTROPHILS ARE REPLACED BY MACROPHAGES WITH INCREASED DEPOSITION OF FIBRIN STRANDS

19. PNEUMONIA: PATHOLOGICAL CHANGES
4. RESOLUTION (STAGE BEGINS BY 8-14 DAYS): COMPLETE RESOLUTION OCCURS IN 1-3 WEEKS AFTER INITIAL
INFECTION
GROSSLY:
 PREVIOUS SOLID FIBRINOUS CONSTITUENT ARE LIQUEFIED BY ENZYMATIC ACTION, EVENTUALLY RESTORING NORMAL APPEARANCE OF
AFFECTED LOBE
 CUT SURFACE APPEARS GREY-RED OR DIRTY BROWN & FROTHY, YELLOW & CREAMY FLUID CAN BE SEEN ON PRESSING
MICROSCOPICALLY:
 MACROPHAGES ARE PREDOMINANT IN ALVEOLAR SPACES
 ALVEOLAR CAPILLARIES ARE ENGORGED
 PROGRESSIVE REMOVAL OF FLUID CONTENT & CELLULAR EXUDATES FROM AIR SPACES VIA EXPECTORATION WHICH RESTORES NORMAL
LUNG PARENCHYMA

21. PNEUMONIA: PATHOLOGICAL CHANGES
BRONCHOPNEUMONIA
GROSSLY:
 PATCHY AREAS OF RED OR GREY CONSOLIDATION AFFECTING ONE OR MORE LOBES
 CROSS SECTIONS SHOW DRY, GRANULAR, FIRM, RED CONSOLIDATED AREAS OF 3-4 CM IN DIAMETER
MICROSCOPICALLY:
 ACUTE INFLAMMATION OF BRONCHIOLES CAN BE SEEN
 SUPPURATIVE EXUDATES IN PERIBRONCHIOLAR ALVEOLI
 ALVEOLAR SEPTA THICKENING CAN BE SEEN, CONGESTED CAPILLARIES & LEUKOCYTE INFILTRATION

23. PNEUMONIA: PATHOLOGICAL CHANGES
INTERSTITIAL PNEUMONIA
GROSSLY:
 LUNGS APPEAR HEAVY WITH CONGESTION. FROTHY OR BLOODY FLUID CAN BE SEEN IN SECTIONED LUNGS
MICROSCOPICALLY:
 THICKENING OF ALVEOLAR WALL CAN BE SEEN WITH INFLAMMATORY INFILTRATE & EDEMA
 NECROTIZING INFLAMMATION OF BRONCHIOLES CAN ALSO BE SEEN
 ALVEOLAR LUMINA MAY SHOW EDEMA FLUID, FIBRIN, INFLAMMATORY EXUDATES

25. LUNG ABSCESS

26. PATHOLOGICAL CHANGES
GROSSLY:
 ABSCESSES MAY BE OF VARIABLE SIZES FROM FEW MILLIMETERS TO LARGE CAVITIES OF 5-6 CM IN DIAMETER.
 IINITIALLY THE ABSCESS IS POORLY DEFINED AND IS SURROUNDED BY PNEUMONIA, BUT IN CHRONIC STATE IT
DEVELOPS FIBROUS WALL.
MICROSCOPICALLY:
 PRESENCE OF SUPPURATIVE EXUDATES IN THE LUNG CAVITIES SURROUNDED BY ACUTE INFLAMMATION IN WALL,
WHICH IS REPLACED BY EXUDATES OF LYMPHOCYTES, PLASMA CELLS AND MACROPHAGES
 IN CHRONIC CASES THERE IS CONSIDERABLE FIBROBLASTIC PROLIFERATION FORMING A FIBROCOLLAGENIC WALL.

27. EMPHYSEMA

28. PATHOLOGICAL CHANGES
GROSSLY:
 LUNGS APPEAR VOLUMINOUS, PALE WITH ROUNDED EDGES
 MILD CASES SHOW DILATATION OF AIR SPACES, WHILE IN SEVERE CASES THEIR IS PRESENCE
OF SUBPLEURAL BULLAE (AIR-FILLED CYST LIKE BUBBLE, > 1 CM IN DIAMETER) AND BLEBS BULGING OUTWARDS
FROM SURFACE OF THE LUNGS (RESULTS FROM THE RUPTURE OF ALVEOLI DIRECTLY
INTO THE SUBPLEURAL INTERSTITIAL TISSUE).
MICROSCOPICALLY:
 DILATATION OF AIR SPACES AND DESTRUCTION OF SEPTAL WALL OF THE PART OF THE ACINUS INVOLVED.

30. BRONCHIAL ASTHMA

31. PATHOLOGICAL CHANGES
GROSSLY:
 LUNGS ARE OVERDISTENDED DUE TO OVERINFLATION SHOWING OCCLUSION OF BRONCHI AND BRONCHIOLES BY
VISCID MUCOUS PLUGS.
MICROSCOPICALLY:
 BRONCHIAL WALL SHOWS THICKENED BASEMENT MEMBRANE OF BRONCHIAL EPITHELIUM ALONG
WITH HYPERTROPHY OF SUBMUCOSAL GLAND AS WELL AS OF THE BRONCHIAL SMOOTH MUSCLE

32. CHRONIC
OBSTRUCTIVE
PULMONARY DISEASE
(COPD)

33. PATHOLOGICAL CHANGES
GROSSLY:
 BRONCHIAL WALL IS THICKENED, HYPEREMIC AND EDEMATOUS.
 PRESENCE OF MUCUS PLUG IN BRONCHI AND BRONCHIOLES.
MICROSCOPICALLY:
 HYPERTROPHY AND HYPERPLASIA OF SUB MUCOSAL GLANDS IN CARTILAGE CONTAINING LARGER AIRWAYS, WHICH
IS ASSESSED BY INCREASED REID INDEX (IT IS THE RATIO BETWEEN THICKNESS OF THE SUB MUCOSAL GLANDS TO
THAT OF BRONCHIAL WALL).

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