Test your knowledge with our General Pathology Q&A. Covers key concepts for Year 3 medical students. Master disease processes today!
College of Health Sciences MBChB III Unit Title: Pathology Continuous Assessment Date: July 2021 Time: 3 Hours SECTION A: MULTIPLE CHOICE QUESTIONS 1. Malignant neoplasms show all the following features EXCEPT : a) Disorganized cell structureb) Encapsulationc) Invasion of local and distant tissuesd) Rapid, erratic growth Answer: b) Encapsulation Explanation: Malignant neoplasms are characteristically NOT encapsulated. Encapsulation is a feature of benign tumors that helps distinguish them from malignant ones. Malignant tumors show irregular borders, invasive growth patterns, and lack the fibrous capsule that typically surrounds benign tumors. 2. One of the following cells has the least capacity for regeneration : a) Cardiac muscleb) Skeletal musclec) Neuronal cellsd) Liver cells Answer: c) Neuronal cells Explanation: Neuronal cells are permanent cells with minimal to no regenerative capacity once mature. While cardiac muscle also has limited regeneration, neurons in the central nervous system essentially cannot regenerate after injury, making them the most vulnerable to permanent loss. 3. The following are mediators of inflammation EXCEPT : a) Interferonsb) Prostaglandinsc) Tumor Necrosis Factor (TNF)d) Myeloperoxidase enzyme Answer: d) Myeloperoxidase enzyme Explanation: Myeloperoxidase is an enzyme found in neutrophil granules that generates reactive oxygen species for antimicrobial activity, but it is not a mediator of inflammation. The other options are all inflammatory mediators that regulate various aspects of the inflammatory response. 4. Metaplasia refers to: a) Irregular, atypical proliferative changes in epithelial or mesenchymal cellsb) Loss of cell substance producing shrinkage of the cellsc) Replacement of one type of adult cell by another type of adult celld) None of the above Answer: c) Replacement of one type of adult cell by another type of adult cell Explanation: Metaplasia is the reversible replacement of one differentiated cell type with another mature differentiated cell type. This typically occurs as an adaptive response to chronic irritation or inflammation, such as respiratory epithelium changing from ciliated columnar to squamous in smokers. 5. Metastatic calcification is associated with: a) Dead or dying tissuesb) Atherosclerosisc) Pancreatic cancerd) Damaged heart valves Answer: None of the options correctly describe metastatic calcification Explanation: Metastatic calcification occurs in normal tissues due to elevated serum calcium or phosphate levels (hypercalcemia or hyperphosphatemia). The options listed describe dystrophic calcification, which occurs in damaged or necrotic tissues with normal serum calcium levels. 6. Which of these is an endogenous pigment? a) Melaninb) Coalc) Tattooingd) Lipid Answer: a) Melanin Explanation: Melanin is an endogenous pigment produced by melanocytes. Coal and tattooing represent exogenous pigments introduced from outside the body, while lipid is not classified as a pigment but rather as a macromolecule. 7. Phagocytes include the following EXCEPT : a) Neutrophilsb) Macrophagesc) Osteoclastsd) Lymphocytes Answer: d) Lymphocytes Explanation: Lymphocytes are primarily involved in adaptive immunity and do not function as professional phagocytes. Neutrophils and macrophages are classic phagocytes, while osteoclasts are specialized phagocytic cells that resorb bone matrix. 8. The commonest cause of infectious granulomas is: a) Tuberculosisb) Fungal infectionsc) Viral infectionsd) Toxins Answer: a) Tuberculosis Explanation: Mycobacterium tuberculosis is the most common cause of infectious granulomatous inflammation worldwide. TB characteristically produces caseating granulomas with central necrosis, epithelioid cells, and Langhans giant cells. 9. The most common fixative used to preserve tissue in histopathology is: a) 10% Formalinb) Ethylene Glycolc) Haematoxylind) 95% Ethanol Answer: a) 10% Formalin Explanation: 10% neutral buffered formalin is the most widely used fixative in histopathology. It cross-links proteins and nucleic acids to preserve tissue morphology and prevent autolysis and bacterial decay. 10. The following are oncogenic viruses in humans EXCEPT : a) Human Papilloma Virus (HPV)b) Epstein Barr Virus (EBV)c) Hepatitis B Virusd) Polio Virus Answer: d) Polio Virus Explanation: Poliovirus is not oncogenic. HPV causes cervical and other cancers, EBV is associated with Burkitt lymphoma and nasopharyngeal carcinoma, and Hepatitis B virus is linked to hepatocellular carcinoma. 11. The RB gene , "the guardian of the genome," regulates the cell cycle at: a) G1/S checkpointb) G2 checkpointc) G0 restriction checkpointd) Intra-S checkpoint Answer: a) G1/S checkpoint Explanation: The RB (retinoblastoma) gene product controls the G1/S checkpoint, preventing cells from entering S phase until appropriate growth signals are received. Note: p53 is actually called "the guardian of the genome," not RB. 12. TP53 is regulated and scavenged after completing its action by: a) CDKN1Ab) MDM2c) RASd) E6 Answer: b) MDM2 Explanation: MDM2 (Mouse Double Minute 2) is the primary negative regulator of p53. It binds to p53 and promotes its degradation through the ubiquitin-proteasome pathway, creating a negative feedback loop. 13. Mutations in the TGF-Beta signaling pathway involving SMAD molecules usually result in: a) Colon cancerb) Stomach cancerc) Lung cancerd) Breast cancer Answer: a) Colon cancer Explanation: TGF-β signaling pathway mutations, particularly involving SMAD2 and SMAD4, are commonly associated with colorectal carcinogenesis. TGF-β normally functions as a tumor suppressor in epithelial cells. 14. The most commonly mutated oncoprotein in all tumors and a key participant in abnormal signal transduction pathways is: a) ABLb) TP53c) BRAFd) RAS Answer: d) RAS Explanation: RAS proteins are mutated in approximately 30% of all human cancers, making them the most commonly mutated oncoproteins. RAS mutations lead to constitutive growth signals and are found in many cancer types. 15. The Warburg effect in tumor cellular metabolism refers to: a) Oxidative phosphorylation in tumor cellsb) Aerobic glycolysis in tumor cellsc) Mutations in enzymes regulating the Krebs cycled) Defective mitochondrial ATP synthesis Answer: b) Aerobic glycolysis in tumor cells Explanation: The Warburg effect describes the preference of cancer cells for glycolysis over oxidative phosphorylation for energy production, even in the presence of adequate oxygen. This metabolic reprogramming supports rapid cell division. 16. A granuloma is comprised of: a) Fibroblasts and capillariesb) Capillaries and giant cellsc) Endothelial cells and neutrophilsd) Central necrotic area, epithelioid cells, and lymphocytes Answer: d) Central necrotic area, epithelioid cells, and lymphocytes Explanation: Granulomas are organized collections of epithelioid cells (activated macrophages) surrounded by lymphocytes, often with multinucleated giant cells and a central area of necrosis in caseating granulomas. 17. During autopsy, one of the following is NOT the role of the medical officer: a) Identify the decedentb) Ascertain the cause of deathc) Document evidenced) Request for autopsy Answer: d) Request for autopsy Explanation: The medical officer performing the autopsy does not request the autopsy. Autopsy requests typically come from coroners, magistrates, families, or other authorized personnel. The pathologist's role is to perform and interpret the examination. 18. The postmortem interval can be estimated using the following EXCEPT : a) Rigor mortisb) Algor mortisc) Mummificationd) Cadaveric spasm Answer: c) Mummification Explanation: Mummification is a late postmortem change that occurs over months to years in specific environmental conditions. It cannot be used to estimate postmortem interval in the acute setting, unlike the other early postmortem changes. 19. Exhumation of human remains in Kenya may only proceed on the authority of: a) Valid court o