Introduction to Pathology and Cellular Responses

Comprehensive practice questions covering introductory pathology concepts including cellular adaptations, injury, and death types based on the lecture notes.

What is the etymological origin of the word 'Pathology'?

It is derived from the Greek words 'pathos' ($suffering$) and 'logos' ($study$).

What are the four core aspects of a disease process studied in pathology?

1. Etiology ($cause$), 2. Pathogenesis ($biochemical and molecular mechanisms$), 3. Morphologic changes ($structural alterations$), and 4. Clinical manifestations ($functional consequences$).

Define hypertrophy.

An increase in the size of cells that results in an increase in the size of the affected organ, involving larger cells but no new cells.

What is the primary mechanism behind hypertrophy?

Increased production of cellular proteins.

Give an example of physiologic hypertrophy induced by hormones.

The massive growth of the uterus during pregnancy.

How is hyperplasia defined?

An increase in the number of cells in an organ or tissue in response to a stimulus.

What are the mechanisms of hyperplasia?

Growth factor-driven proliferation of mature cells and, in some cases, increased output of new cells from tissue stem cells.

Define atrophy.

A reduction in the size of an organ or tissue due to a decrease in cell size and number.

What are the six common causes of pathologic atrophy?

1. Decrease workload, 2. Diminished blood supply, 3. Loss of nerve stimulus, 4. Loss of endocrine stimulation, 5. Inadequate nutrition, and 6. Pressure.

What is metaplasia?

A reversible change in which one differentiated cell type (epithelial or mesenchymal) is replaced by another cell type better able to withstand a particular stress.

Provide an example of epithelial metaplasia seen in cigarette smokers.

The replacement of normal columnar ciliated epithelial cells in the trachea and bronchi by stratified squamous epithelial cells.

Distinguish between Ischemia and Anoxia.

Ischemia is the cut off of blood flow circulation, while Anoxia is insufficient oxygen often due to lowered Hb, respiratory effects, or poisons.

Name two features of reversible cell injury recognizable under a light microscope.

Cellular swelling and fatty change.

Define 'Hydropic change'.

The accumulation of water in a cell, often due to hypoxia causing decreased aerobic respiration in mitochondria and decreased $ATP$ production.

What are the three patterns of nuclear breakdown in necrosis?

1. Pyknosis ($shrinking and clumping of the nucleus$), 2. Karyolysis ($nuclear dissolution and chromatin lysis$), and 3. Karyorrhexis ($fragmentation of the nucleus$).

How does cell size differ between Necrosis and Apoptosis?

In Necrosis, cell size is enlarged ($swelling$); in Apoptosis, cell size is reduced ($shrinkage$).

What is Coagulative necrosis?

A type of necrosis typically seen in hypoxic environments where the outline of dead cells is maintained and tissue remains firm, such as in myocardial or kidney infarcts.

In which organ is liquefactive necrosis commonly associated with ischemia?

The brain ($cerebral infarction$).

What is Caseous necrosis and what is a typical cause?

A specific 'cheese-like' form of coagulation necrosis typically caused by mycobacteria, such as in tuberculosis lesions.

What characterizes Fat necrosis of the pancreas?

The release of powerful enzymes that damage fat to produce soaps, appearing macroscopically as soft, chalky white areas.

What is Fibrinoid necrosis?

A special form of necrosis usually seen in immune reactions involving blood vessels.

List the six principal mechanisms of cell injury.

1. $ATP$ depletion, 2. Mitochondrial damage, 3. Loss of calcium homeostasis, 4. Accumulation of oxygen-derived free radicals ($ROS$), 5. Defective membrane permeability, and 6. Damage to DNA and proteins.