general Pathology Q&A

**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 (re