CLASE TEÓRICA 6 - INFLAMACIÓN Y REPARACIÓN TISULAR PARTE 2

Understanding Purulent Exudate and Its Implications

Characteristics of Purulent Exudate

• Purulent exudate is characterized by a high content of pus, consisting histologically of abundant necrotic material. This type of necrosis is often active or liquefactive, typically resulting from infections.

• The mechanism behind purulent exudate involves cellular lysis, with the presence of numerous neutrophils that are often destroyed or degraded.

Abscess Formation

• An abscess is defined as a collection of purulent material within a newly formed cavity, which can occur in various organs. The transcript includes an image showing multiple abscesses on the liver surface.

• A specific example noted is an abscess located beneath the diaphragm, appearing as white-yellowish deposits in autopsy findings.

Types of Exudates and Their Associations

• The discussion includes examples such as serofibrinous exudates seen in global pneumonia and purulent fibrinous exudates observed in intestinal sections.

• Empyema is introduced as another acute inflammatory process involving the accumulation of purulent material within preformed cavities like the thoracic or abdominal cavities.

Histological Features and Granulation Tissue

• Granulation tissue develops from exudates and consists of newly formed blood vessels (neoformed vessels), young fibroblasts, and inflammatory infiltrates.

• This granulation tissue differs from fibrous tissue due to its youthful fibroblast composition and concurrent inflammatory response.

Erosions vs. Ulcers: Key Differences

Definitions and Characteristics

• Erosions are superficial losses of substance that do not penetrate beyond the basal membrane in skin or mucosal tissues; they are often multiple.

• In contrast, ulcers represent deeper excavations that breach muscular layers or basal membranes, necessitating granulation tissue for healing.

Clinical Examples

• Chronic gastritis may present with erosions across mucosal surfaces; these erosions can be widespread but remain superficial compared to ulcers.

• A duodenal ulcer example illustrates macroscopic features such as elevated borders and clean bases, distinguishing it from neoplastic processes.

Fistulas: Definition and Clinical Relevance

Understanding Fistulas

• A fistula is described as an abnormal passage connecting two hollow organs or one organ to the skin; it may arise congenitally or due to pathological conditions.

Inflammation in Different Organs

Examples of Inflammation

• The presence of an elongated, swollen cecal appendix is noted, with a reddish serosal surface indicating possible acute appendicitis.

• The macroscopic characteristics observed may suggest early-stage acute appendicitis.

Gallbladder Inflammation

• A gallbladder specimen shows loss of normal mucosal characteristics and multiple ulcerations, indicative of inflammation.

• Yellowish necrotic areas and dark hemorrhagic zones are present; thickening of the gallbladder wall suggests edema.

• This condition is identified as microhemorrhagic cholecystitis, which can have infectious etiologies involving various microorganisms.

Esophageal Infection

• An esophageal section reveals irregular mucosa with yellowish-white plaques, indicative of candidiasis caused by Candida albicans, often seen in immunocompromised patients.

Pulmonary Infections

• Observations indicate exudative consolidation in the lungs, potentially affecting entire lobes or large portions thereof, termed global pneumonia.

• The lung cut shows congestive aspects with black areas representing anthracosis; pleural thickening may indicate pleuritis.

Characteristics of Pneumonia

• Histologically, global pneumonia features fibrinous leukocytic exudate filling alveolar spaces; initial inflammatory phenomena include vasocongestion.

• Pneumonia progresses through stages: congestion, hepatization (red to gray), and resolution phases.

Bronchopneumonia Insights

• A lobular view indicates disseminated consolidation typical of bronchopneumonia, which differs from global pneumonia by its bilateral nature and scattered lesions.

Chronic Inflammation Development

• Discussion on potential evolution from acute to chronic inflammation leading to fibrosis; complications like stenosis can arise in hollow organs.

Fibrous Bands Formation

• Notable fibrous bands between intestinal loops suggest post-peritonitis or surgical manipulation consequences related to chronic inflammation.

Understanding Chronic Inflammation

• Chronic inflammation persists over weeks or months and involves ongoing tissue damage alongside repair attempts.

• It can be classified as nonspecific or specific based on histological appearance; specific chronic inflammation includes granulomatous diseases.

Granulomatous Diseases

Inflammation of Lymphatic Vessels and Granuloma Formation

Lymphangitis and Regional Adenopathy

• The process of inflammation in lymphatic vessels is referred to as lymphangitis, which can lead to the spread of infection to regional lymph nodes, resulting in regional adenopathy or tuberculous adenitis.

Characteristics of Tuberculosis Lesions

• Observations of tuberculosis lesions reveal the formation of granulomas, which are small inflammatory nodules composed of various cellular elements.

Composition of Granulomas

• A granuloma consists primarily of modified macrophages known as epithelioid cells, resembling epithelial cells. Other components may include fibroblasts and chronic inflammatory elements like lymphocytes and plasma cells.

Multinucleated Giant Cells

• Modified macrophages can merge to form multinucleated giant cells, which vary in nuclear arrangement. These structures are significant in understanding chronic inflammation processes.

Chronic Inflammation Dynamics