Veterinary Public Health and Epidemiology- ICAR JRF/SRF 2024

• Chronic Passive Hyperemia (Congestion):
• General passive hyperemia results from impaired systemic venous return to the heart:
• Valvular Stenosis: Narrowing of the atrioventricular (mitral/tricuspid) or semilunar valves impedes forward blood flow.
• Valvular Insufficiency: Incompetent valve closure leads to regurgitant backward blood flow.
• Both valvular lesions elevate upstream venous pressure, triggering chronic passive congestion in the lungs (left heart failure) or liver ("nutmeg liver") and systemic organs (right heart failure).
• nalysis:
• ((B) and (D) only): Correct.

Correct option: (3) (B) and (D) only.

• Definition and Triad of Cirrhosis:
• Cirrhosis is the irreversible end-stage morphological alteration of chronic liver injury characterized by:

• Diffuse, massive bridging fibrosis (deposition of type I and III collagen by activated hepatic stellate cells).
• Parenchymal destruction and formation of regenerative nodules of hepatocytes lacking normal central-vein architecture.
• Structural vascular reorganization and architectural distortion leading to portal hypertension and hepatic insufficiency.
  • nalysis:

• Both (A) and (R) are true, and (R) provides the definitive pathological explanation of (A). Hence, Option 1 is correct.

• Lymphoid Leukosis in Domestic Poultry:
• Commonly referred to as "Big liver disease" due to massive diffuse nodular enlargement of the liver (hepatomegaly) and spleen. True.
• Caused by exogenous Avian Leukosis Viruses (ALV, family Retroviridae), transmitted both vertically through the egg albumen/yolk and horizontally. True.
• Neoplastic transformation specifically targets B lymphocytes originating in the bursa of Fabricius. (In contrast, Marek's disease transforms T lymphocytes!). Statement C is False.
• The disease has a long incubation period, manifesting clinically in sexually mature adult birds ($\gt 16-24\text{ weeks}$ of age). True.
• nalysis:
• Statements (A), (B), and (D) are correct. Hence, Option 2 is correct.