Cell Injury and Adaptation - Pathology ACEM MCQ

In relation to atrophy, which of the following statements is FALSE? 1. Decreased autophagic vacuoles 2. Decreased myofilaments 3. Decreased smooth endoplasmic reticulum 4. Persistance of residual bodies

1. Decreased autophagic vacuoles There is an INCREASE of AUTOPHAGIC vacuoles in atrophy Atrophy is characterized by SHRIKAGE and LOSS of structural ELEMENTS of cell (like myofilaments, ER). There is an INCREASE in autophagic VACUOLES, into which LYSOSOMES DISCHARGE their hydrolytic contents. Some cell debris resists digestion, and they persist as membrane bound residual bodies in cytoplasm (e.g., Lipofuscin granules).

With regards to dysplasia, which of the following features is CORRECT? 1. It is characterised by cellular pleomorphism 2. It inevitably progresses to cancer 3. It is not associated with architectural abnormalities 4. It is a feature of mesenchymal cells

1. It is characterised by cellular pleomorphism Dysplasia means DISORDERED GROWTH and is encountered principally in the EPITHELIA. It is characterised by a constellation of changes which include a LOSS in the UNIFORMITY of the individual cells, as well as a loss in their ARCHITECTURAL ORIENTATION. Dysplastic cells exhibit considerable PLEOMORPHISM (variation in shape and size). Dysplasia does not necessarily progress to cancer. Only if the ENTIRE THICKNESS of the epithelium BECOMES DYSPLASTIC is it LIKELY to progress to a CARCINOMA in SITU. Otherwise - the process is usually reversible.

In relation to hypertrophy, which of the following statements is CORRECT? 1. It is triggered by specific hormonal stimulation 2. It increases the function of an organ exponentionally 3. It is usually pathological 4. It occurs after partial hepatectomy

1. It is triggered by specific hormonal stimulation HYPERTROPHY describes increase in the size of the organ due to increase in cell size, not number. The hypertrophied organ has NO NEW CELLS, but larger cells. The increased SIZE of the cells is due to the synthesis of MORE structural COMPONENTS. HYPERTROPHY can be PHYSIOLOGICAL and PATHOLOGICAL and can occur together with hyperplasia (e.g., pregnant uterus). Breast undergoes HYPERTROPHY during lactation, but in PUBERTY and PREGNANCY the breast undergoes HYPERPLASIA. Other triggers of hypertrophy include mechanical and trophic triggers. Ultimately, the hypertrophied ORGAN reaches the LIMIT when it is NO longer ABLE to COMPENSATE for increased demand, and failure ensues. After partial HEPATECTOMY the liver undergoes compensatory HYPERPLASIA.

Metastatic calcification may occurs in which of the following situations? 1. Atherosclerotic vessels 2. Gastric mucosa 3. Damaged heart valves 4.Tuberculous lymph nodes

2. Gastric mucosa METASTATIC calcification occurs in NORMAL tissues and is associated with a RAISED SERUM calcium The FOUR principal causes of hypercalcaemia; - Increased PTH - Destruction of bone - Vit D related disorders - Renal failure METASTATIC calcification may occur widely throughout the body but mainly affects the interstitial tissues of the GASTRIC MUCOSA, KIDNEYS, LUNGS, SYSTEMIC arteries and PULMONARY VEINS. These tissues excrete acid and therefore have an internal alkaline medium that predisposes them to metastatic calcification. NB!: atherosclerotic vessels typically have dystrophic calcium deposits

Regarding dystrophic calcification, which of the following statements is CORRECT? 1. It may be caused by multiple myeloma 2. It causes organ dysfunction 3. It is associated with hypercalcaemia 4. Calcuim deposition occurs in viable tissues

2. It causes organ dysfunction Dystrophic calcification occurs in NON-VIABLE (damaged) or DYING tissues. It occurs despite NORMAL serum LEVELS of calcium and in the ABSENCE of derangements in calcium METABOLISM. Although DYSTROPHIC calcification may be a simple sign of a previous cell injury, it is often a cause of ORGAN DYSFUNCTION. Myeloma causes destruction of bone and an increase calcium level and thus is associated with metastatic calcification There are two types of calcification: - dystrophic - metastatic Metastatic calcification is associated with increased level of Ca and is often due to a malignant process and tissue destruction (e.g. malignant process)

Which of the following is an example of hypertrophy? 1. Increased respiratory epithelium in response to vitamin A deficiency 2. Increased size of female breast during puberty 3. Increase in size of female uterus during pregnancy 4. Increase in liver size after partial hepatectomy

3. Increase in size of female uterus during pregnancy Hypertrophy refers to INCREASE in the SIZE of the cells and, with such change, an increase in the size of the organ. The hypertrophied organ has NO NEW cells, but LARGER ones. The increased SIZE of the cells is NOT due to cellular SWELLING but to the synthesis of MORE structural COMPONENTS. It can be PHYSIOLOGICAL and PATHOLOGICAL and can occur together with HYPERPLASIA (e.g., pregnant uterus). The breast hypertrophies during lactation, but during PUBERTY and PREGNANCY the BREAST undergoes HYPERPLASIA. Following a partial HEPATECTOMY, the liver undergoes compensatory HYPERPLASIA. NB!: Vit A deficiency induces respiratory epithelium METAPLASIA.

Which of the following statements is CORRECT in relation to dystrophic calcification? 1. It rarely causes dysfunction 2. It does not occur on heart valves 3. It is formed by crystalline calcium phosphate 4. It is specific to coagulative necrosis

3. It is formed by crystalline calcium phosphate. Dystrophic calcification occurs in NON-VIABLE or DYING tissues. It occurs despite NORMAL serum CALCIUM LEVELS of, and in the ABSENCE of DERANGEMENTS in calcium METABOLISM. Although dystrophic calcification may be a simple sign of a previous cell injury, it is often a cause of organ dysfunction. Myeloma causes destruction of bone and increase calcium level and is thus associated with metastatic calcification. DYSTROPHIC calcification occurs in ALL types of necrosis including coagulative, caseous and liquifactive.

With regard to metaplasia, which of the following statements is CORRECT? 1. It is typically an irreversible process 2. It preserves mucus secretion in the respiratory tract 3. It is the process that occurs in Barrett's oesophagitis 4. It can be caused by vitamin B12 deficiency

3. It is the process that occurs in Barrett's oesophagitis Metaplasia is a REVERSIBLE change in which one adult cell type is REPLACED by another adult cell type. It is an ADAPTIVE substitution of cells, which are sensitive to stress, by cell types better able to withstand the adverse environment. The MOST COMMON metaplasia is COLUMNAR to SQUAMOUS occurring in the bronchial tree due to smoking. Metaplasia of SQUAMOUS to COLUMNAR type occurs in Barrett's oesophagitis. Vitamin A deficiency induces squamous metaplasia in the respiratory epithelium which is a reversible process. If the stimulus which has predisposed to such a metaplasia persists, it may induce malignant transformation.

All the following are features of apoptosis, with the EXCEPTION of? 1. Chromatin condensation 2. Formation of cytoplasmic blebs 3. Cell swelling 4. Phagocytosis of apoptotic bodies

4. Cell swelling Cell SHRINKAGE occurs during APOPTOSIS - a form of cell death whereby no harmful substances are released into the surrounding tissue. It is the body's natural process for removing old, diseased or unnecessary cells. Apoptotic cells usually exhibit a distinctive constellation of biochemical alterations that underline structural changes. These include: - Activation of CASPASES: the presence of cleaved, active caspases is a MARKER for cells undergoing APOPTOSIS. - DNA BREAKDOWN - Membrane ALTERATIONS and recognition by phagocytes

Reversible cell injury is characterised by all of the following, EXCEPT? 1. Detachment of ribosomes 2. Nuclear chromatin clumping 3. Cellular swelling 4. Lysosomal rupture

4. Lysosomal rupture In REVERSIBLE injury, there is: - CELLULAR swelling - ORGANELLE swelling - BLEBBING of the plasma MEMBRANE - DETACHMENT of RIBOSOMES from the ER - nuclear CHROMATIN CLUMPING - DECREASED ATP generation - loss of cell membrane integrity - defects in protein synthesis - cytoskeleton damage - DNA damage To enter the "point of no return", or irreversible injury, the cell it goes through the various stages of reversible injury, so features often may overlap. However, nucleus DESTRUCTION in IRREVERSIBLE injury includes PYKNOSIS - KARYORRHEXIS and KARYOLYSIS. Other features of irreversible cell injury include: - LYSOSOMAL rupture - DISRUPTION of the cellular MEMBRANES and DEPLETION of ATP.

Which of the following is an example of hypertrophy? 1. The breast at puberty 2. Tissue with a high capillary to myocyte ratio 3. The liver post hepatectomy 4. The pregnant uterus

4. The pregnant uterus HYPERPLASIA (increase in CELL NUMBER) - breast in puberty - breast in pregnancy - liver after resection HYPERTROPHY (increase in the CELL SIZE) - breast during lactation - pregnant uterus - myocardium in cardiac failure NB!: In muscular hypertrophy, capillary growth is not able to match myocyte growth, hence Capillary / Myocyte ratio decreases in hypertrophy

Which of the following statements is CORRECT regarding metastases? 1. They are proven by the finding of lymph node enlargement adjacent to a tumour 2. They are the most common presentation of melanoma 3. The breast usually metastasises to supraclavicular nodes 4. They unequivocally prove malignancy

4. They unequivocally prove malignancy Metastases are tumour implants that are discontinuous with the primary tumour. Metastases UNEQUIVOCALLY mark a tumour as malignant, because BENIGN tumours DO NOT METASTATISE. BREAST cancers usually metastasise to the AXILLARY lymph nodes - the natural lymphatic drainage route. Lymph node enlatgement adjacent to a tumour may be reactive or inflammatory in nature.