Homeostasis MCQs With Answer

Homeostasis MCQs With Answer: For B. Pharm students, mastering homeostasis is essential to understand drug effects on physiological balance. This concise, keyword-rich introduction and question set covers cellular homeostasis, feedback mechanisms, endocrine and renal regulation, thermoregulation, electrolyte and acid–base balance, osmoregulation, and pharmacological disruptions. These practice multiple choice questions emphasize clinical correlations, mechanism-based reasoning, and exam-style problem solving. Each MCQ includes clear options and correct answers to help B. Pharm learners improve retention, identify weak areas, and prepare for university exams and competitive tests. Use these targeted questions to strengthen concepts like negative and positive feedback, insulin–glucagon dynamics, and fluid-electrolyte interactions. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the primary definition of physiological homeostasis?

• The maintenance of a constant internal environment despite external changes
• The process of cell division to replace dead cells
• The generation of ATP in mitochondria
• The absorption of nutrients in the gut

Correct Answer: The maintenance of a constant internal environment despite external changes

Q2. Which mechanism is most commonly involved in maintaining blood glucose homeostasis after a meal?

• Increased glucagon secretion from alpha cells
• Insulin-mediated glucose uptake by muscle and adipose tissue
• Activation of the renin-angiotensin system
• Decreased hepatic glycogen synthesis

Correct Answer: Insulin-mediated glucose uptake by muscle and adipose tissue

Q3. Negative feedback in homeostasis refers to:

• A response that amplifies the initial stimulus
• A response that reduces or counteracts deviation from a set point
• A one-time corrective action that does not repeat
• A system regulated solely by the central nervous system

Correct Answer: A response that reduces or counteracts deviation from a set point

Q4. Which hormone primarily lowers blood glucose concentration?

• Glucagon
• Cortisol
• Insulin
• Growth hormone

Correct Answer: Insulin

Q5. The osmoreceptors that detect plasma osmolality are primarily located in the:

• Medulla oblongata
• Hypothalamus
• Pituitary gland
• Adrenal cortex

Correct Answer: Hypothalamus

Q6. Antidiuretic hormone (ADH) acts mainly on:

• Proximal tubule to increase sodium reabsorption
• Collecting ducts to increase water permeability
• Loop of Henle to increase urea secretion
• Distal tubule to inhibit potassium secretion

Correct Answer: Collecting ducts to increase water permeability

Q7. Which electrolyte imbalance is most likely to cause cardiac arrhythmias?

• Hyponatremia
• Hypokalemia
• Hypermagnesemia
• Hypophosphatemia

Correct Answer: Hypokalemia

Q8. The primary buffering system for acute changes in blood pH is:

• Phosphate buffer in intracellular fluid
• Hemoglobin buffer system in red blood cells
• Bicarbonate buffer system in plasma
• Protein buffers in extracellular matrix

Correct Answer: Bicarbonate buffer system in plasma

Q9. Which process increases core body temperature during cold exposure?

• Vasodilation of cutaneous vessels
• Decreased thyroid hormone secretion
• Shivering thermogenesis
• Sweating

Correct Answer: Shivering thermogenesis

Q10. In the renin-angiotensin-aldosterone system, the main effect of aldosterone is to:

• Decrease blood pressure by vasodilation
• Increase sodium reabsorption and potassium secretion in the kidney
• Inhibit renin release from the juxtaglomerular apparatus
• Promote water excretion independent of sodium

Correct Answer: Increase sodium reabsorption and potassium secretion in the kidney

Q11. Which transporter is chiefly responsible for glucose reabsorption in the proximal tubule?

• GLUT4
• SGLT2
• Na+/K+ ATPase on apical membrane
• GLUT2 on apical membrane

Correct Answer: SGLT2

Q12. Fever as a homeostatic response is primarily mediated by:

• Hypothalamic reset due to pyrogens
• Direct skin warming by cytokines
• Increased ADH secretion
• Suppression of leukocyte activity

Correct Answer: Hypothalamic reset due to pyrogens

Q13. Which of the following best describes feedforward control?

• Response based solely on previous errors
• Anticipatory regulation that minimizes deviation before it occurs
• Delayed feedback after a change in the variable
• Random fluctuations without regulatory control

Correct Answer: Anticipatory regulation that minimizes deviation before it occurs

Q14. Which organ is the primary regulator of long-term acid-base balance via bicarbonate regeneration?

• Liver
• Kidney
• Lung
• Pancreas

Correct Answer: Kidney

Q15. Peripheral chemoreceptors that monitor arterial PO2 are located in the:

• Medulla
• Carotid and aortic bodies
• Hypothalamus
• Pulmonary alveoli

Correct Answer: Carotid and aortic bodies

Q16. Which hormone increases blood calcium by stimulating osteoclast activity?

• Calcitonin
• Parathyroid hormone (PTH)
• Insulin
• Thyroxine (T4)

Correct Answer: Parathyroid hormone (PTH)

Q17. Homeostatic failure leading to diabetes mellitus type 1 is primarily due to:

• Insulin resistance in peripheral tissues
• Autoimmune destruction of pancreatic beta cells
• Excessive glucagon production by alpha cells
• Inappropriate ADH secretion

Correct Answer: Autoimmune destruction of pancreatic beta cells

Q18. Which feature distinguishes osmoregulation from volume regulation?

• Osmoregulation refers to total body sodium content
• Volume regulation focuses on extracellular fluid volume often influenced by sodium
• They are identical processes with different names
• Osmoregulation only occurs in the liver

Correct Answer: Volume regulation focuses on extracellular fluid volume often influenced by sodium

Q19. A compensatory metabolic alkalosis would show which arterial blood gas pattern?

• Elevated pH, elevated HCO3-, elevated PaCO2
• Low pH, low HCO3-, low PaCO2
• Normal pH, low HCO3-, high PaCO2
• Low pH, high HCO3-, high PaCO2

Correct Answer: Elevated pH, elevated HCO3-, elevated PaCO2

Q20. Which physiologic change occurs in dehydration?

• Decreased plasma osmolality
• Increased ADH release and water reabsorption
• Increased atrial natriuretic peptide (ANP) release
• Enhanced thirst suppression

Correct Answer: Increased ADH release and water reabsorption

Q21. Gluconeogenesis during fasting is stimulated by:

• Insulin secretion
• High cellular ATP inhibiting enzymes
• Increased glucagon and cortisol levels
• Activation of phosphofructokinase-1

Correct Answer: Increased glucagon and cortisol levels

Q22. Which receptor type mediates rapid cellular responses to changes in extracellular ion concentrations?

• G-protein-coupled receptors (GPCRs)
• Intracellular steroid receptors
• Ion channel-linked receptors
• Tyrosine kinase receptors

Correct Answer: Ion channel-linked receptors

Q23. The physiological role of aldosterone in potassium homeostasis is to:

• Decrease potassium secretion in the distal tubule
• Increase potassium uptake into skeletal muscle
• Enhance potassium secretion by principal cells in the collecting duct
• Block ROMK channels permanently

Correct Answer: Enhance potassium secretion by principal cells in the collecting duct

Q24. Which change is expected during acute respiratory acidosis?

• Decreased PaCO2 and increased pH
• Increased PaCO2 and decreased pH
• Increased HCO3- without change in PaCO2
• Metabolic compensation occurs immediately

Correct Answer: Increased PaCO2 and decreased pH

Q25. Baroreceptor reflex to a sudden drop in blood pressure will cause:

• Decreased sympathetic outflow and bradycardia
• Increased parasympathetic tone to the heart
• Increased sympathetic activity, vasoconstriction, and tachycardia
• Immediate natriuresis to lower blood volume

Correct Answer: Increased sympathetic activity, vasoconstriction, and tachycardia

Q26. Which organ system provides the fastest response to changes in plasma potassium?

• Renal excretion adjustments
• Cellular uptake by insulin-stimulated transport
• Slow changes in bone storage
• Gastrointestinal secretion

Correct Answer: Cellular uptake by insulin-stimulated transport

Q27. Which term describes a regulated variable set point that can be altered physiologically (e.g., fever)?

• Homeostasis
• Allostasis
• Allergy
• Steady-state rigidity

Correct Answer: Allostasis

Q28. Which effect of sympathetic activation helps maintain homeostasis during hemorrhage?

• Bronchoconstriction to conserve oxygen
• Peripheral vasodilation to increase blood flow to skin
• Increased heart rate and peripheral vasoconstriction to maintain blood pressure
• Inhibition of renin release

Correct Answer: Increased heart rate and peripheral vasoconstriction to maintain blood pressure

Q29. Heat loss through evaporation is most effective when:

• Ambient humidity is high
• Ambient temperature is lower than skin temperature and humidity is low
• There is no sweat production
• Cutaneous blood flow is maximal

Correct Answer: Ambient temperature is lower than skin temperature and humidity is low

Q30. Which of the following best explains insulin resistance at the molecular level?

• Increased GLUT4 translocation to membrane
• Post-receptor defects in insulin signaling pathways
• Excessive insulin receptor sensitivity
• Overexpression of hexokinase

Correct Answer: Post-receptor defects in insulin signaling pathways

Q31. Which kidney structure senses decreased perfusion and triggers renin release?

• Macula densa
• Proximal tubule cells
• Juxtaglomerular cells
• Collecting duct principle cells

Correct Answer: Juxtaglomerular cells

Q32. Which electrolyte change is characteristic of metabolic acidosis?

• Hyperkalemia due to H+/K+ shifts
• Hypokalemia due to increased renal loss
• Hypernatremia caused by water retention
• Hypocalcemia from decreased PTH release

Correct Answer: Hyperkalemia due to H+/K+ shifts

Q33. Which pharmacologic agent can impair thermoregulation by inhibiting sweating?

• Beta-blockers
• Anticholinergics
• ACE inhibitors
• Loop diuretics

Correct Answer: Anticholinergics

Q34. Homeostatic control of plasma osmolality primarily involves which two processes?

• Sweating and shivering
• ADH release and thirst stimulation
• Insulin secretion and glucagon suppression
• Renin release and aldosterone inhibition

Correct Answer: ADH release and thirst stimulation

Q35. Which ion channel dysfunction is most directly linked to cystic fibrosis affecting homeostasis?

• Voltage-gated sodium channel mutation in neurons
• CFTR chloride channel mutation impairing epithelial ion transport
• Defective calcium channels in muscle cells
• Overactive potassium channels in pancreatic beta cells

Correct Answer: CFTR chloride channel mutation impairing epithelial ion transport

Q36. In volume expansion with normal osmolality, which hormone is typically increased to promote natriuresis?

• Antidiuretic hormone (ADH)
• Aldosterone
• Atrial natriuretic peptide (ANP)
• Renin

Correct Answer: Atrial natriuretic peptide (ANP)

Q37. Which physiological adaptation helps prevent large swings in intracellular calcium concentration?

• High extracellular potassium concentration
• Sequestration in the endoplasmic reticulum and binding proteins
• Active exocytosis of calcium by neurons
• Rapid renal excretion of calcium within minutes

Correct Answer: Sequestration in the endoplasmic reticulum and binding proteins

Q38. Which laboratory finding indicates respiratory compensation for metabolic acidosis?

• Elevated PaCO2 with increased HCO3-
• Decreased PaCO2 due to hyperventilation
• Normal PaCO2 with very low HCO3- and no pH change
• Increased PaCO2 due to hypoventilation

Correct Answer: Decreased PaCO2 due to hyperventilation

Q39. Which of the following drugs can cause hypokalemia by increasing renal potassium excretion?

• ACE inhibitors
• Potassium-sparing diuretics
• Loop diuretics like furosemide
• Angiotensin receptor blockers

Correct Answer: Loop diuretics like furosemide

Q40. Which mechanism explains how the body conserves heat in cold environments?

• Increased skin blood flow and sweating
• Peripheral vasoconstriction and increased metabolic rate
• Activation of parasympathetic tone to reduce shivering
• Enhanced urinary water loss

Correct Answer: Peripheral vasoconstriction and increased metabolic rate

Q41. Which statement about endocrine control of homeostasis is true?

• Endocrine signals always act faster than neural signals
• Hormones can modulate set points and produce prolonged effects
• Endocrine systems are not integrated with neural feedback
• Hormones are only involved in reproduction, not homeostasis

Correct Answer: Hormones can modulate set points and produce prolonged effects

Q42. Which parameter is sensed by the juxtaglomerular apparatus to regulate GFR and renin release?

• Systemic arterial oxygen concentration
• Sodium chloride concentration at the macula densa
• Plasma protein concentration in Bowman’s space
• Renal medullary interstitial pH

Correct Answer: Sodium chloride concentration at the macula densa

Q43. During prolonged exercise, which homeostatic process helps maintain blood glucose?

• Suppression of glucagon and hepatic gluconeogenesis
• Increased insulin secretion from pancreas
• Glycogenolysis and gluconeogenesis stimulated by catecholamines and glucagon
• Immediate renal glucose excretion to lower plasma glucose

Correct Answer: Glycogenolysis and gluconeogenesis stimulated by catecholamines and glucagon

Q44. Which of the following best explains the role of the hypothalamus in homeostasis?

• It only controls circadian rhythms and not metabolic processes
• It integrates autonomic, endocrine, and behavioral responses to maintain internal milieu
• It is only responsible for long-term hormonal adjustments via the thyroid
• It functions exclusively in voluntary motor control

Correct Answer: It integrates autonomic, endocrine, and behavioral responses to maintain internal milieu

Q45. What homeostatic disturbance results from excessive ADH secretion (SIADH)?

• Hypernatremia due to water loss
• Hyponatremia due to water retention
• Hypokalemia from increased renal potassium excretion
• Metabolic alkalosis due to bicarbonate retention

Correct Answer: Hyponatremia due to water retention

Q46. Which transporter is upregulated in skeletal muscle in response to insulin?

• SGLT1
• GLUT4
• Na+/K+ ATPase on apical membrane
• GLUT1 constitutive transporter

Correct Answer: GLUT4

Q47. Which of the following is an example of a physiological positive feedback loop?

• Baroreceptor reflex stabilizing blood pressure
• Oxytocin release during childbirth intensifying uterine contractions
• Insulin release lowering glucose after a meal
• Thermoregulatory vasodilation reducing heat

Correct Answer: Oxytocin release during childbirth intensifying uterine contractions

Q48. Which acid-base disorder is commonly seen with chronic obstructive pulmonary disease (COPD)?

• Acute metabolic acidosis
• Chronic respiratory acidosis with metabolic compensation
• Respiratory alkalosis without compensation
• Metabolic alkalosis due to vomiting

Correct Answer: Chronic respiratory acidosis with metabolic compensation

Q49. Homeostatic imbalance leading to hypernatremia most commonly results from:

• Excessive water intake relative to sodium
• Water loss exceeding sodium loss (e.g., dehydration)
• Increased ADH causing water retention
• Excessive aldosterone causing hyponatremia

Correct Answer: Water loss exceeding sodium loss (e.g., dehydration)

Q50. In pharmacology, understanding homeostasis is important because:

• Drugs never affect feedback mechanisms
• Drugs can alter set points, signaling pathways, and compensatory responses leading to therapeutic or adverse effects
• Homeostasis only matters in physiology courses, not drug therapy
• All drugs act only on the kidneys to restore balance

Correct Answer: Drugs can alter set points, signaling pathways, and compensatory responses leading to therapeutic or adverse effects

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

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