Adaptive changes – atrophy MCQs With Answer

Adaptive changes – atrophy MCQs With Answer provide B. Pharm students a focused, exam-oriented review of cellular adaptation and mechanisms of atrophy. This concise guide covers pathology concepts such as decreased cell size, reduced protein synthesis, increased autophagy, denervation, ischemia, hormonal deprivation and disuse, and links these to pharmacological implications and therapeutics. Each MCQ emphasizes clinical correlations, diagnostic clues and drug interactions relevant to atrophy, helping pharmacy students strengthen recall and application skills. Ideal for university exams, competitive tests and quick revision, these questions enhance understanding of pathophysiology and its impact on drug action and dosage adjustments. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the primary cellular change that defines atrophy?

• Increase in cell size
• Decrease in cell size
• Replacement of one cell type by another
• Increase in cell number

Correct Answer: Decrease in cell size

Q2. Which of the following mechanisms is most directly responsible for protein degradation in atrophying muscle?

• Lysosomal cathepsins only
• Ubiquitin–proteasome pathway
• Mitochondrial oxidative phosphorylation
• Decreased transcription of ribosomal RNA

Correct Answer: Ubiquitin–proteasome pathway

Q3. Which E3 ubiquitin ligases are key regulators of skeletal muscle atrophy?

• p53 and Rb
• Atrogin-1 (MAFbx) and MuRF1
• mTOR and AKT
• Caspase-3 and caspase-9

Correct Answer: Atrogin-1 (MAFbx) and MuRF1

Q4. Autophagy during atrophy primarily results in degradation of:

• Extracellular matrix proteins
• Whole organelles and cytoplasmic components
• Nuclear DNA only
• Ribosomal RNA exclusively

Correct Answer: Whole organelles and cytoplasmic components

Q5. Which clinical condition commonly causes disuse atrophy of skeletal muscle?

• Regular exercise
• Immobilization in a cast
• Hyperthyroidism
• Pregnancy

Correct Answer: Immobilization in a cast

Q6. Denervation atrophy results from loss of:

• Vascular supply to the tissue
• Neural input to the muscle
• Hormonal stimulation only
• Exposure to toxins

Correct Answer: Neural input to the muscle

Q7. Which histologic feature is commonly seen in atrophic cells?

• Increased cytoplasmic basophilia
• Abundant rough endoplasmic reticulum
• Autophagic vacuoles and reduced organelle content
• Marked nuclear enlargement and hyperchromasia

Correct Answer: Autophagic vacuoles and reduced organelle content

Q8. Aging-related atrophy often involves accumulation of which pigment in cells?

• Bilirubin
• Melanin
• Lipofuscin
• Hemosiderin

Correct Answer: Lipofuscin

Q9. In endocrine atrophy, which hormonal change can cause uterine atrophy?

• Excess estrogen
• Deficiency of estrogen after menopause
• High progesterone levels
• Excess growth hormone

Correct Answer: Deficiency of estrogen after menopause

Q10. Cachexia-associated atrophy in chronic disease is often mediated by which cytokine?

• Interleukin-10 (IL-10)
• Interleukin-6 (IL-6) and TNF-α
• Erythropoietin
• Insulin-like growth factor 1 (IGF-1)

Correct Answer: Interleukin-6 (IL-6) and TNF-α

Q11. Which molecular pathway promotes cell survival and opposes atrophy in muscle?

• FOXO transcription factors
• mTOR/AKT signaling
• Ubiquitin ligase activation
• Autophagy induction

Correct Answer: mTOR/AKT signaling

Q12. Prolonged glucocorticoid therapy may cause which type of adaptive change?

• Cardiac hypertrophy
• Skeletal muscle atrophy
• Renal hypertrophy
• Hepatocellular hyperplasia

Correct Answer: Skeletal muscle atrophy

Q13. Which statement differentiates atrophy from apoptosis?

• Atrophy always involves cell death, apoptosis does not
• Apoptosis is an adaptive decrease in cell size
• Atrophy is reduction in cell size or number but not necessarily programmed cell death; apoptosis is programmed cell death
• Both are identical processes at molecular level

Correct Answer: Atrophy is reduction in cell size or number but not necessarily programmed cell death; apoptosis is programmed cell death

Q14. Which biochemical marker may be elevated during acute muscle breakdown but not during chronic disuse atrophy?

• Creatine kinase (CK)
• Serum albumin
• Hemoglobin
• Serum creatinine clearance

Correct Answer: Creatine kinase (CK)

Q15. Which pharmacologic approach can counteract muscle atrophy in cachexia?

• Myostatin inhibitors
• Beta-blockers
• ACE inhibitors
• Statins

Correct Answer: Myostatin inhibitors

Q16. In neuronal atrophy, what is a common cause within the CNS?

• Excessive synaptic activity
• Loss of afferent stimulation or trophic factors
• Hyperplasia of glial cells
• Overexpression of growth factors

Correct Answer: Loss of afferent stimulation or trophic factors

Q17. Which lab finding supports denervation atrophy of a limb muscle?

• Normal EMG activity
• Fibrillation potentials on electromyography (EMG)
• Elevated serum lipids
• Increased bone density

Correct Answer: Fibrillation potentials on electromyography (EMG)

Q18. Which cellular organelle is often reduced in number during atrophy?

• Nucleolus
• Mitochondria
• Centrosomes
• Peroxisomes only

Correct Answer: Mitochondria

Q19. Reversible atrophy implies that:

• Cells are irreversibly dead
• Cell size can be restored if the stimulus is removed
• New cell types replace old ones
• It immediately progresses to cancer

Correct Answer: Cell size can be restored if the stimulus is removed

Q20. Which drug class is known to worsen muscle atrophy when used chronically?

• Anabolic steroids
• Glucocorticoids
• Insulin sensitizers
• Selective serotonin reuptake inhibitors (SSRIs)

Correct Answer: Glucocorticoids

Q21. Which of the following is an example of physiological atrophy?

• Atrophy of the thymus with age
• Atrophy due to tumor compressing an organ
• Disuse atrophy after immobilization
• Atrophy from chronic infection

Correct Answer: Atrophy of the thymus with age

Q22. What role does IGF-1 play in muscle homeostasis?

• Promotes protein degradation
• Stimulates protein synthesis and growth via AKT/mTOR
• Directly activates ubiquitin ligases
• Induces autophagy leading to atrophy

Correct Answer: Stimulates protein synthesis and growth via AKT/mTOR

Q23. Which feature distinguishes atrophy from hypoplasia?

• Atrophy follows previously normal size; hypoplasia is incomplete development
• Hypoplasia occurs after injury to a mature organ
• Atrophy always involves increased cell number
• They are synonymous

Correct Answer: Atrophy follows previously normal size; hypoplasia is incomplete development

Q24. Which intracellular signaling increases expression of atrophy-related genes (atrogenes)?

• Activation of FOXO transcription factors
• Activation of PI3K-AKT pathway
• Upregulation of IGF-1 signaling
• mTOR activation

Correct Answer: Activation of FOXO transcription factors

Q25. In the context of pharmacology, why is understanding atrophy important for B. Pharm students?

• It has no relevance to drug therapy
• Atrophic changes can alter drug distribution, metabolism and dosing requirements
• It only affects surgical decisions
• It solely predicts allergic reactions

Correct Answer: Atrophic changes can alter drug distribution, metabolism and dosing requirements

Q26. Which factor promotes autophagy and may contribute to atrophy under nutrient deprivation?

• Activation of mTOR
• Inhibition of AMPK
• Activation of AMPK and inhibition of mTOR
• Excess insulin signaling

Correct Answer: Activation of AMPK and inhibition of mTOR

Q27. Which morphological change is typical in brain tissue undergoing atrophy?

• Enlargement of gyri and decreased sulci
• Widening of sulci and ventricular enlargement
• Massive inflammatory infiltrate
• Diffuse hypercellularity

Correct Answer: Widening of sulci and ventricular enlargement

Q28. Limb immobilization leads to atrophy primarily by which mechanism?

• Increased muscle protein synthesis
• Decreased muscle protein synthesis and increased proteolysis
• Enhanced satellite cell proliferation
• Increased nerve activity

Correct Answer: Decreased muscle protein synthesis and increased proteolysis

Q29. Which laboratory technique can demonstrate increased autophagic vacuoles in atrophic cells?

• Light microscopy without stains
• Transmission electron microscopy
• Electrocardiography
• Ultrasonography

Correct Answer: Transmission electron microscopy

Q30. Hepatic atrophy can occur due to portohepatic shunting; this represents which cause?

• Increased workload
• Decreased blood supply or trophic stimulation
• Endocrine overstimulation
• Autoimmune hyperactivity

Correct Answer: Decreased blood supply or trophic stimulation

Q31. Which growth factor decline contributes to age-related muscle atrophy (sarcopenia)?

• Transforming growth factor-beta (TGF-β)
• Insulin-like growth factor 1 (IGF-1)
• Vascular endothelial growth factor (VEGF)
• Platelet-derived growth factor (PDGF)

Correct Answer: Insulin-like growth factor 1 (IGF-1)

Q32. Which therapeutic strategy directly targets the ubiquitin–proteasome system to reduce atrophy?

• Proteasome inhibitors
• mTOR inhibitors
• Beta-agonists
• Calcium channel blockers

Correct Answer: Proteasome inhibitors

Q33. Muscle atrophy due to thyroid hormone excess (thyrotoxicosis) is mainly because:

• Thyroid hormone increases anabolic processes
• Thyroid hormone increases catabolism and protein breakdown
• Thyroid hormone reduces metabolic rate
• It causes nerve hypertrophy

Correct Answer: Thyroid hormone increases catabolism and protein breakdown

Q34. Which is a clinical sign of testicular atrophy?

• Increased testicular size
• Decreased testosterone and reduced testicular volume
• Hyperpigmentation of scrotal skin
• Excessive sperm production

Correct Answer: Decreased testosterone and reduced testicular volume

Q35. Which process contributes to neuronal atrophy after axonal injury?

• Retrograde degeneration and loss of trophic support
• Increased synaptic formation
• Enhanced myelination
• Proliferation of neuronal cell bodies

Correct Answer: Retrograde degeneration and loss of trophic support

Q36. Chronic ischemia causing organ atrophy is primarily due to:

• Excessive nutrient delivery
• Reduced oxygen and nutrient supply leading to decreased cell function and survival
• Hyperplasia of vascular smooth muscle
• Excessive endocrine stimulation

Correct Answer: Reduced oxygen and nutrient supply leading to decreased cell function and survival

Q37. Which imaging finding suggests renal atrophy?

• Enlarged kidneys with increased cortical thickness
• Reduced renal size with cortical thinning
• Diffuse hepatic steatosis
• Increased adrenal size

Correct Answer: Reduced renal size with cortical thinning

Q38. Which of the following best explains loss of thymic mass with age?

• Pathologic infection of the thymus
• Physiologic involution and atrophy due to hormonal changes
• Autoimmune hyperplasia
• Excessive growth factor stimulation

Correct Answer: Physiologic involution and atrophy due to hormonal changes

Q39. In skeletal muscle, satellite cells are important for recovery from atrophy because they:

• Produce cytokines that cause further atrophy
• Differentiate into new muscle fibers and help regeneration
• Inhibit protein synthesis
• Convert muscle to adipose tissue

Correct Answer: Differentiate into new muscle fibers and help regeneration

Q40. Which pathological process is least likely to be an example of adaptive atrophy?

• Atrophy of the endometrium after menopause
• Muscle wasting in prolonged bed rest
• Cancerous infiltration causing tissue loss
• Thymic involution in adults

Correct Answer: Cancerous infiltration causing tissue loss

Q41. Which lab or molecular marker indicates increased proteasomal activity in atrophic muscle?

• Decreased ubiquitin conjugates
• Increased expression of atrogin-1 and MuRF1
• Elevated heavy-chain myosin synthesis
• High levels of IGF-1

Correct Answer: Increased expression of atrogin-1 and MuRF1

Q42. Which nutritional deficiency can contribute to generalized tissue atrophy?

• Excess vitamin A intake
• Protein–calorie malnutrition
• High protein diet
• Excessive carbohydrate intake

Correct Answer: Protein–calorie malnutrition

Q43. Which pharmacological agent is used experimentally to counteract sarcopenia by stimulating anabolic pathways?

• mTOR inhibitors
• IGF-1 analogs or AKT activators
• Proteasome activators
• Glucocorticoids

Correct Answer: IGF-1 analogs or AKT activators

Q44. Which change is typically reversible after removal of the atrophic stimulus?

• Permanent scarring and fibrosis only
• Decrease in cell size without significant cell loss
• Total loss of tissue architecture
• Irreversible DNA mutations

Correct Answer: Decrease in cell size without significant cell loss

Q45. Cardiac atrophy can occur with which of the following?

• Persistent high blood pressure leading to hypertrophy
• Chronic disuse such as prolonged bed rest or mechanical unloading with ventricular assist devices
• Athletic training
• Hyperthyroidism-induced tachycardia

Correct Answer: Chronic disuse such as prolonged bed rest or mechanical unloading with ventricular assist devices

Q46. Which cellular sensor detects low energy states and can promote autophagy leading to atrophy?

• mTORC1
• AMP-activated protein kinase (AMPK)
• Protein kinase A (PKA)
• Ras GTPase

Correct Answer: AMP-activated protein kinase (AMPK)

Q47. In pharmacotherapy, dose adjustments may be needed in atrophic organs because:

• Atrophy always increases drug-metabolizing enzyme activity
• Changes in organ mass can alter drug distribution and clearance
• Atrophy makes no difference to pharmacokinetics
• All drugs become ineffective

Correct Answer: Changes in organ mass can alter drug distribution and clearance

Q48. Which experimental intervention has been shown to reduce muscle atrophy in animal models?

• Systemic glucocorticoid administration
• Resistance exercise or electrical muscle stimulation
• High-dose proteasome activators
• Extended immobilization

Correct Answer: Resistance exercise or electrical muscle stimulation

Q49. Which is a hallmark morphological sign of long-standing organ atrophy on gross examination?

• Organ enlargement with nodularity
• Reduction in organ size and weight with surface puckering
• Diffuse hemorrhagic lesions
• Marked hyperemia

Correct Answer: Reduction in organ size and weight with surface puckering

Q50. Which therapeutic consideration is important when treating infections in atrophic tissues?

• Atrophic tissues always have increased blood flow improving drug delivery
• Reduced perfusion and trophic support may impair delivery of antibiotics and require dose/formulation adjustments
• Drug choice is irrelevant in atrophic tissue
• All topical drugs are equally effective regardless of atrophy

Correct Answer: Reduced perfusion and trophic support may impair delivery of antibiotics and require dose/formulation adjustments

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