Veterinary Pathology- ICAR JRF/SRF 2024

• Patterns of Irreversible Cell Death:
• Oncotic Necrosis (Oncosis):
• The morphological progression of irreversible cell injury resulting from acute severe ATP depletion (hypoxia, ischemia) and plasma membrane pump failure.
• Characterized by cellular swelling (oncosis), mitochondrial swelling, plasma membrane rupture, and liberation of intracellular contents triggering severe inflammation.
• Apoptosis: Programmed, energy-dependent cell shrinkage without membrane lysis or inflammation.
• nalysis:
• (Oncotic necrosis): Correct.

Correct option: (2) Oncotic necrosis

• Pathophysiology of Edema:
• Assertion (A): Inflammatory edema is the excessive accumulation of fluid in tissue spaces and body cavities.
• Generally, inflammatory swelling produces a protein-rich exudate resulting from increased microvascular endothelial permeability.
• Reason (R): Edema is generally due to decrease in colloid osmotic pressure.
• Decreased plasma colloid osmotic pressure (hypoalbuminemia) produces a protein-poor transudate (non-inflammatory edema). It does NOT explain inflammatory edema.
• nalysis:
• In evaluating standard competitive exam questions, the statement distinction between transudative systemic mechanisms and localized inflammatory exudation is tested (Option 4).

Correct option: (4) (A) is false but (R) is true.

• 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.

• Programmed Cell Death: Apoptosis is an active, gene-regulated, energy (ATP)-dependent mechanism of programmed cell death wherein individual cells activate intrinsic biochemical suicide pathways.
• Morphological Hallmarks: Characterized by cell shrinkage, chromatin condensation (pyknosis), nuclear fragmentation (karyorrhexis), and blebbing of the plasma membrane into intact apoptotic bodies that are rapidly phagocytosed without eliciting inflammatory responses.
• Contrasting Processes:
• Oncosis: Accidental, non-programmed cell death caused by energy depletion and membrane failure leading to cellular swelling, blebbing, rupture, and acute inflammation.
• Autolysis: Post-mortem enzymatic self-digestion of cells by their own lysosomal enzymes.
• Putrefaction: Post-mortem decomposition of tissues by saprophytic bacteria accompanied by gas and foul-smelling catabolites.

Correct option: (3) Apoptosis

Evaluating the Assertion and Reason concerning Inflammation – definitions associated with inflammatory phenomenon:

The correct answer is Option 1: Both (A) and (R) are true and (R) is the correct explanation of (A).