Fluid/electrolyte/acid-base Exam Questions With Complete Solutions/Detailed Review And Study Guide {2025/2026 Edition} Graded A+

1. Excess blood plasma in the bloodstream initiates the thirst mechanism to restore fluid balance. a. True b. False - ANSWER b. False 2. Antidiuretic hormone (ADH) causes increased water loss through the urine. a. True b. False - ANSWER b. False 3. The most important trigger for aldosterone release is the renin-angiotensin mechanism, mediated by the 4. renal tubules. a. True b. False - ANSWER a. True 5. Blood buffers are important in maintaining blood pressure. a. True b. False - ANSWER b. False 6. The bicarbonate buffer system prevents changes in blood pH through the action of carbonic acid and its salt, 7. sodium bicarbonate. a. True b. False - ANSWER a. True 8. When blood pH becomes too acidic, the tubule cells of the kidneys excrete bicarbonate ions and retain hydrogen ions. a. True b. False - ANSWER b. False 9. Which of these describes polycystic kidney disease? a. inability to retain water, with polyuria and constant thirst b. chronic kidney infection c. chronic inflammation and scar tissue formation d. enlarged kidney with urine-filled, blister like sacs - ANSWER d. enlarged kidney with urine-filled, blister like sacs 10. What is the major risk factor for developing polycystic kidney disease? a. frequent urinary tract infections b. alcoholism c. brain damage d. family history - ANSWER d. family history 11. The need to urinate frequently at night, which plagues over 50% of the elderly, is called ________. a. cystitis b. incontinence c. urgency d. nocturia - ANSWER d. nocturia 12. Untreated streptococcal infections in childhood that can lead to the kidney infection characterized by antigen-antibody complexes clogging the glomerular filters is known as ________. a. glomerulonephritis b. cystitis c. urethritis d. hypospadias - ANSWER a. glomerulonephritis 13. A feeling that it is necessary to void, which is experienced more regularly in the elderly, is known as ________. a. urethritis b. nocturia c. frequency d. urgency - ANSWER d. urgency 14. The need to get up during the night to urinate is called ________. a. hypospadias b. urgency c. nocturia d. frequency e. glomerulonephritis - ANSWER c. nocturia 15. The degenerative condition in which blister like sacs (cysts) containing urine form on the kidneys and obstruct urine drainage is called ________. a. polycystic kidney b. epispadias c. cystitis d. hypospadias e. dysuria - ANSWER a. polycystic kidney 16. Hypospadias is a condition of male children that involves ________. a. inflammation of the glomerulus b. atrophied prostate c. closing of the foreskin over the end of the penis d. cysts on the kidneys e. opening of the urethra on the ventral surface of the penis - ANSWER e. opening of the urethra on the ventral surface of the penis 17. Sexually transmitted infections (STIs) are primarily infections of the reproductive tracts but may also cause urinary tract infections. a. True b. False - ANSWER a. True 18. Childhood streptococcal infections that go untreated can lead to ________. a. renal calculi b. cystitis c. nocturia d. glomerulonephritis e. urethritis - ANSWER d. glomerulonephritis 19. Control of the voluntary urethral sphincter in normal children is related to ________. a. hormone regulation b. muscular development c. enzymatic regulation d. nervous system development e. intelligence - ANSWER d. nervous system development 20. From childhood through late middle age, one of the most common bacteria to infect and inflame the urinary tract and cause urethritis and cystitis is ________. a. Mycobacterium tuberculosis b. Clostridium botulinum c. streptococcus d. Escherichia coli e. staphylococcus - ANSWER d. Escherichia coli 21. Incontinence is often the final outcome of the urinary system during the aging process. a. True b. False - ANSWER a. True 22. Angiotensin I is converted to angiotensin II when _____ occurs. a. Low blood pressure b. Dehydration c. Low blood volume d. Two of the above of the above e. All of the above - ANSWER e. All of the above 23. The action(s) of Angiotensin II include a. Dilation of blood vessels body wide b. Release of ADH c. Release of renin d. Two of the above e. None of the above - ANSWER e. None of the above 24. Aldosterone a. Is released from the posterior pituitary b. Causes TBW to decrease c. Causes concentrated urine to be formed d. Causes salt to be secreted (Na+ and Cl-) e. Two of the above - ANSWER c. Causes concentrated urine to be formed 25. Low blood pressure will lead to the release of a. Aldosterone b. ADH c. Aldosterone and ADH d. Neither aldosterone nor ADH - ANSWER c. Aldosterone and ADH 26. Which of these is a pH buffer system in the body? a. Bicarbonate b. Phosphate c. Protein d. Two of the above e. All of the above - ANSWER e. All of the above 27. The biggest source of extra acid in the body fluids is a. Food b. Cellular metabolism - ANSWER b. Cellular metabolism 28. What is the largest fluid compartment in the body? a. plasma b. interstitial fluid (IF) c. extracellular fluid (ECF) d. intracellular fluid (ICF) - ANSWER d. intracellular fluid (ICF) 29. Increased respiration will _____ pH. c. Increase d. Decrease - ANSWER c. Increase 30. What is the main effect of antidiuretic hormone (ADH)? a. increases water content of urine b. triggers micturition c. reduces water content of urine d. elevates sodium content of urine - ANSWER c. reduces water content of urine 31. . What statement describes the effect of aldosterone? a. It increases glucose secretion. b. It increases water secretion. c. It stimulates calcium reabsorption. d. It stimulates sodium reabsorption. - ANSWER d. It stimulates sodium reabsorption. 32. Which fluid compartment contains the greatest fluid volume? a. interstitial fluid (IF) b. plasma c. intracellular fluid (ICF) d. extracellular fluid (ECF) - ANSWER c. intracellular fluid (ICF) 33. What is the primary action of antidiuretic hormone? a. It reduces reabsorption of sodium. b. It causes kidney-collecting ducts to reabsorb more water. c. It causes kidney-collecting ducts to secrete more water. d. It causes the urinary bladder to reabsorb more water. - ANSWER b. It causes kidney-collecting ducts to reabsorb more water. 34. Which of these describes the direct effect of aldosterone? a. It stimulates the secretion of renin. b. It stimulates the secretion of water. c. It causes sodium reabsorption and potassium excretion. d. It activates angiotensin. - ANSWER c. It causes sodium reabsorption and potassium excretion. 35. Which of these is a major chemical buffer system of blood? a. hemoglobin buffer system b. NaOH buffer system c. hydrochloric acid buffer system d. bicarbonate buffer system - ANSWER d. bicarbonate buffer system 36. Hypoaldosteronism leads to which of the following conditions? a. polyuria b. oliguria c. anuria d. Hypoaldosteronism leads to all of these conditions. - ANSWER a. polyuria 37. About two-thirds of body fluid is found within living cells; this fluid is called the ________. a. extracellular fluid or ECF b. plasma c. lymph d. intracellular fluid or ICF - ANSWER d. intracellular fluid or ICF 38. The driving force for water intake is ________. a. the thirst mechanism b. glomerular filtration c. the renin-angiotensin mechanism d. metabolism - ANSWER a. the thirst mechanism 39. After a brain injury, George developed diabetes insipidus. What specific part of George's brain was damaged? a. posterior pituitary gland b. pons c. medulla d. cerebellum - ANSWER a. posterior pituitary gland Highly sensitive cells within the hypothalamus that react to changes in blood solute concentration and cause the release of antidiuretic hormone (ADH) when appropriate are called ________. a. osmoreceptors b. mechanoreceptors c. thermoreceptors d. baroreceptors - ANSWER a. osmoreceptors The abnormal condition that results from the lack of ADH release, causing huge amounts of very dilute urine to be voided, is called ________. a. glomerulonephritis b. diabetes mellitus c. urethritis d. diabetes insipidus - ANSWER d. diabetes insipidus The hormone released by the posterior pituitary to prevent excessive water loss in the urine is ________. a. antidiuretic hormone (ADH) b. aldosterone c. cortisol d. insulin - ANSWER a. antidiuretic hormone (ADH) Arterial blood pH above 7.45 is considered to be ________. a. alkalosis b. physiological acidosis c. normal d. acidosis - ANSWER b. physiological acidosis A strong acid will dissociate and liberate more ________ ions in water than a weak acid. a. potassium b. bicarbonate c. sodium d. hydrogen - ANSWER d. hydrogen The kidneys can help maintain a rising blood pH by excreting ________ ions and reabsorbing ________ ions by the tubule cells. a. bicarbonate; hydrogen b. hydrogen; bicarbonate c. carbon dioxide; oxygen d. ammonia; carbonic acid - ANSWER a. bicarbonate; hydrogen Who has the highest percentage of water in the body? a. elderly male b. elderly female c. adult female d. infant e. adult male - ANSWER d. infant The fluid stored inside cells is referred to as extracellular fluid (ECF). a. True b. False - ANSWER b. False Which of the following is the major stimulus for the thirst mechanism? a. increased osmolarity of blood plasma b. hunger c. increased saliva production d. decreased urination e. two of the above - ANSWER a. increased osmolarity of blood plasma Extracellular fluid is found everywhere in the body EXCEPT ________. a. humors of the eye and lymph b. cerebrospinal fluid c. interstitial fluid d. blood plasma e. within living cells - ANSWER e. within living cells The main hormone that acts on the kidneys to regulate sodium ion concentration of the extracellullar fluid (ECF) is ________. a. epinephrine b. secretin c. ADH d. aldosterone e. renin - ANSWER d. aldosterone Antidiuretic hormone prevents excessive water loss by promoting water reabsorption in the ________. a. proximal convoluted tubule b. distal convoluted tubule c. glomerulus d. collecting duct e. two of the above - ANSWER e. two of the above Aldosterone does NOT directly or indirectly regulate ________. a. magnesium b. sodium c. chlorine d. glucose e. potassium - ANSWER d. glucose What stimulates the release of renin from the juxtaglomerular (JG) apparatus? a. low blood sodium levels b. low blood pressure c. high blood volume d. low blood potassium levels e. two of the above - ANSWER b. low blood pressure What role does angiotensin II play in restoring blood pressure to normal? a. Angiotension II promotes tubular reabsorption of sodium from the filtrate. b. Angiotensin II promotes tubular reabsorption of water from the filtrate. c. Angiotensin II promotes tubular reabsorption of both sodium and water from the filtrate. d. Angiotensin II causes blood vessels to vasoconstrict. e. All of the above - ANSWER d. Angiotensin II causes blood vessels to vasoconstrict. The chemical buffer system that includes carbonic acid and its salt, which ties up the H+ released by strong acids, is called the ________. a. ionic buffer system b. protein buffer system c. bicarbonate buffer system d. carbonic buffer system e. phosphate buffer system - ANSWER c. bicarbonate buffer system Which of these chemicals dissociates completely and liberates all the hydrogen ions when dissolved in water? a. strong acids b. weak acids c. weak bases d. neutral substances e. strong bases - ANSWER a. strong acids . Which system removes excess carbon dioxide from the blood? a. endocrine system b. urinary system c. digestive system d. respiratory system e. two of the above - ANSWER d. respiratory system When blood pH begins to rise, the respiratory control centers in the brain are ________. a. depressed b. not effected c. accelerated d. controlled by the kidneys e. shut off - ANSWER a. depressed How does the urinary system respond to blood that has become acidic? a. both secrete more hydrogen ions and reabsorb more bicarbonate ions b. reabsorb more bicarbonate ions only c. breathing rate increases d. secrete more hydrogen ions only e. breathing rate decreases - ANSWER a. both secrete more hydrogen ions and reabsorb more bicarbonate ions Which of these is true regarding total body water? a. A man typically has more than a woman b. An adult typically has more than an infant c. Both of these statements are true d. Neither of these statements are true - ANSWER d. Neither of these statements are true Most of the body's TBW is a. in the ICF b. in the ECF - ANSWER a. in the ICF Sweat is responsible for the greatest loss of TBW on a daily basis a. True b. False - ANSWER b. False All of these are examples of ECF except a. Blood plasma b. Interstitial fluid c. Intracellular fluid d. Serous fluid e. Cerebrospinal fluid - ANSWER c. Intracellular fluid When TBW is high a. ADH is released from the posterior pituitary b. Aldosterone is released from the adrenal medulla c. Both of the above d. Neither of the above - ANSWER d. Neither of the above TBW increases ADH release and Aldosterone is not released from the adrenal medulla ADH a. Is released from the hypothalamus e. Causes TWB to increase f. Causes dilute urine to be formed g. Causes sodium to be reabsorbed - ANSWER e. Causes TWB to increase The juxtaglomerular apparatus secretes a. ADH b. Aldosterone c. Renin d. Angiotensin II - ANSWER c. Renin