Q&A Hero

Q: The bicarbonate buffer system would not work very well in the human body if not for the action of the respiratory system, which ___________. A. supplies the buffer system with CO2 B. supplies the buffer system with O2 C. expels HCO3- produced by the buffer system D. expels H+ produced by the buffer system E. expels CO2 produced by the buffer system

Q: Which of the following describes an antiport system on the basal side of renal tubule cells? A. It transports bicarbonate from the tubular fluid back into the tubule cells. B. It transports H+ in both directions across the epithelium. C. It transports CO2 from the blood into the tubule cells. D. It exchanges K+ for Na+. E. It exchanges H+ for Na+.

Q: Proteins can buffer a drop in pH with their ___________ side groups and can buffer an increase in pH with their __________ side groups. A. -NH2; -PO4 B. -PO4; -COOH C. -NH2; -COOH D. -COOH; -NH2 E. -PO4; -NH2

Q: Acidosis has what effect on the resting membrane potential of nerve cells? A. It causes repolarization. B. It causes depolarization below threshold. C. It causes hyperpolarization. D. It causes depolarization above threshold.

Q: Which of the following is not a role of calcium in the body? A. It participates in muscle contraction. B. It is a significant component of nucleic acids. C. They serve as second messengers. D. It activates exocytosis. E. It is important in blood clotting.

Q: How is calcium concentration in the body regulated? A. By hormones B. By sodium and calcium concentrations in the plasma C. By chloride and phosphate concentrations in the plasma D. By the parasympathetic nervous system E. By the sympathetic nervous system

Q: Which of the following accurately describes the inorganic phosphates (Pi) of the body fluids? A. They are not a significant component of nucleic acids. B. They are not important for cell membrane structure. C. They are not necessary in the linking of endergonic with exergonic reactions. D. They form crystals with calcium in the presence of calsequestrin. E. They participate in the activation of some enzymes.

Q: Which of the following is a result of phosphate excretion from the body? A. An increase in free potassium ions in the ECF B. An increase in free calcium ions in the ECF C. An increase in free chloride ions in the ICF D. A decrease in free potassium ions in the ECF E. A decrease in free calcium ions in the ECF

Q: Which of the following represents the complete chemical reaction for the bicarbonate buffer system? A. CO2 + H2O H2CO3HCO3- + H+ B. CO2 + H2O HCO3- + H+H2CO3 C. H2CO3CO2 + H2O HCO3- + H+ D. H2CO3HCO3- + H+ E. CO2 + H2O HCO3- + H+

Q: What is the normal pH of tissue fluid? A. 6.95-7.05 B. 7.05-7.15 C. 7.15-7.25 D. 7.25-7.35 E. 7.35-7.45

Q: What are the major chemical buffer systems of the body? A. The urinary and respiratory B. The urinary and digestive C. The bicarbonate, phosphate, and protein D. The bicarbonate, nucleic acids, and protein E. The bicarbonate, phosphate, and nitrate

Q: What protein is the most important buffer in blood plasma? A. Fibrinogen B. Albumin C. Alpha globulin D. Gamma globulin E. Transferrin

Q: What protein is the most important buffer in erythrocytes? A. Albumin B. Fibrinogen C. Gamma globulin D. Hemoglobin E. Myoglobin

Q: Hypokalemia can result from all of the following except __________. A. chronic vomiting B. diarrhea C. heavy sweating D. aldosterone hyposecretion E. excessive use of laxatives

Q: What is the most abundant anion in the ECF? A. HCO3- B. PO43- C. HPO42- D. H2PO4- E. Cl-

Q: Chloride homeostasis is achieved mainly as a result of ____________ homeostasis. A. H2PO4- B. PO43- C. HCO3- D. Na+ E. K+

Q: What is the principal cation of the ECF? A. Ca2+ B. Cl- C. K+ D. Na+ E. Pi

Q: Where are cells with aldosterone receptors found? A. Adrenal cortex B. Adrenal medulla C. Posterior pituitary D. Proximal convoluted tubule E. Distal convoluted tubule

Q: What is the function of aldosterone? A. It increases both Na+ and K+ reabsorption. B. It increases both Na+ and K+ secretion. C. It increases Na+ reabsorption and K+ secretion. D. It reduces Na+ reabsorption and K+ secretion. E. It causes the urine to be more diluted.

Q: Hypernatremia is a plasma __________ concentration above normal. A. Ca2+ B. Na+ C. K+ D. Cl- E. Pi

Q: Which of the following is not caused by hypernatremia? A. Water retention B. Edema C. Hypertension D. Interstitial fluid accumulation E. A reduction in plasma volume

Q: What is the most significant solute in determining the distribution of water among fluid compartments? A. Na+ B. Cl- C. Ca2+ D. K+ E. Pi

Q: Which of the following does not stimulate aldosterone secretion? A. Hypotension B. Hyponatremia C. Hyperkalemia D. High blood sodium concentration E. High blood potassium concentration

Q: Women have a tendency to retain water during part of the menstrual cycle because estrogen mimics the action of what? A. ADH B. Aldosterone C. Atrial natriuretic hormone D. Oxytocin E. Prolactin

Q: What is the most abundant cation in the ICF? A. Ca2+ B. Na+ C. K+ D. Cl- E. Pi

Q: What is the total body water (TBW) content of a 70 kg young male? A. 10 L B. 20 L C. 40 L D. 60 L E. 70 L

Q: What is the greatest determinant of the intracellular water volume? A. K+ B. Na+ C. Ca2+ D. Cl- E. PO43-

Q: Which of these conditions is not a result of hyperkalemia? A. Cells are more excitable. B. The resting membrane potential is more negative. C. The cells are partially depolarized. D. The cells are more sensitive to stimulation. E. There is less diffusion of potassium out of the cells.

Q: Which of the following occurs with hypokalemia? A. Cells are partially depolarized. B. There is more diffusion of potassium into the cells. C. Cells are more excitable. D. The resting membrane potential is more positive. E. Cells are hyperpolarized.

Q: Long-term inhibition of thirst is mostly associated with which of the following? A. Cooling of the mouth B. Distention of the stomach by ingested water C. A drop in blood osmolarity D. Moistening of the mouth E. Increased salivation

Q: The three physiological buffer systems are urinary, digestive, and respiratory.

Q: The kidneys neutralize more acid or base than any other buffer system.

Q: Acidosis is a pH lower than 7, whereas alkalosis is a pH higher than 7.

Q: Uncompensated alkalosis is a pH imbalance that can only be corrected with clinical intervention.

Q: Where is the greatest volume of water in the body found? A. Intracellular fluid (ICF) B. Extracellular fluid (ECF) C. Tissue (interstitial) fluid D. Blood plasma and lymph E. Transcellular fluid

Q: What determines osmosis from one fluid compartment to another? A. The temperature difference between compartments B. The relative concentration of solutes in each compartment C. The relative volume in each compartment D. The relative size of each compartment E. The blood pressure

Q: In which compartment would fluid accumulate in edema? A. Intracellular fluid B. Transcellular fluid C. Tissue (interstitial) fluid D. Blood plasma E. Lymph

Q: Most body water intake is from __________, whereas most body water lost is via __________. A. metabolic water; cutaneous transpiration B. metabolic water; sweat C. drinking; cutaneous transpiration and expired air D. drinking; urine E. drinking; radiation

Q: Fluid intake is governed mainly by hypothalamic neurons called __________. A. baroreceptors B. proprioceptors C. nociceptors D. osmoreceptors E. mechanoreceptors

Q: What is the function of antidiuretic hormone? A. It stimulates angiotensin II secretion. B. It promotes water conservation. C. It stimulates hypothalamic osmoreceptors. D. It inhibits salivation and thirst. E. It targets the cerebral cortex.

Q: Water output is largely controlled by varying ___________. A. metabolic water production B. sweating C. cutaneous transpiration D. drinking E. urine volume

Q: Which of the following occurs when blood volume and pressure become too high? A. ADH release is inhibited. B. ADH release is stimulated. C. The renal tubules reabsorb more water. D. The renal tubules reabsorb more sodium. E. The kidneys produce less urine.

Q: Which of the following can prolonged exposure to cold weather lead to? A. Fluid sequestration in the upper limbs B. Hypotonic hydration C. Hypervolemia D. Increased sensible water loss E. Increased respiratory water loss

Q: In response to dehydration, osmoreceptors stimulate the secretion of __________. A. ADH B. calcitonin C. ANP D. sodium ions E. bicarbonate ions

Q: A hemorrhage results in which of the following? A. A decrease in water volume without significantly affecting the osmolarity B. A decrease in water volume and an increase in osmolarity C. A decrease in water volume and a decrease in osmolarity D. An increase in ECF volume but a decrease in ICF volume E. A decrease in ECF volume but an increase ICF volume

Q: A buffer system converts a weak acid or base into a strong one.

Q: Angiotensin-converting enzyme is found only in the kidneys and converts angiotensinogen to angiotensin I.

Q: Cells in the cleft between the afferent and efferent arterioles and among capillaries of the glomerulus are known as mesangial cells.

Q: Glomerular capillaries suffer little damage from hypertension because of the protective influence of the afferent arterioles.

Q: The fenestrated endothelium of the capillary has pores small enough to exclude blood cells from the filtrate.

Q: The most toxic of our metabolic wastes are nitrogenous wastes.

Q: Blood plasma osmolarity is higher than intracellular fluid osmolarity.

Q: In a state of water balance, average daily fluid gains and losses are equal.

Q: Fluid intake is governed mainly by hypothalamic receptors called osmoreceptors.

Q: The kidneys secrete ADH in response to dehydration.

Q: Hypovolemia refers to a reduction in total body water while maintaining normal osmolarity.

Q: Aldosterone promotes potassium excretion.

Q: Natriuretic peptides promote sodium and potassium excretion.

Q: Hyponatremia is usually a result of hypotonic hydration.

Q: Hypocalcemia causes muscle weakness, whereas hypercalcemia causes potentially fatal muscle tetanus.

Q: Chloride homeostasis is regulated as a side effect of sodium homeostasis.

Q: Glomerular filtration occurs because glomerular oncotic pressure overrides glomerular blood pressure.

Q: A hospital patient produces 4 mL/min of urine with a urea concentration of 8 mg/mL. Venous blood draw reveals urea concentration of 0.4 mg/mL. What is the percentage of cleared urea from glomerular filtrate? A. 40% B. 56% C. 64% D. 72% E. 80%

Q: Which two substances are most useful for determining a patient's glomerular filtration rate? A. Insulin and glucose B. Inulin and creatinine C. Sodium and water D. Albumin and inulin E. Insulin and urea

Q: Creatinine has a renal clearance of 140 mL/min. Why is this? A. It is absorbed by the nephron loop. B. It is secreted by the glomerulus. C. It is absorbed by the renal tubules. D. It is secreted by the renal tubules. E. It is produced in the pulmonary tissue.

Q: Which of the following is not found in the ureter? A. Adventitia B. Two layers of smooth muscle C. Three layers of smooth muscle D. Transitional epithelium E. Skeletal muscle

Q: The __________ muscle is located in the urinary bladder. A. detrusor B. distractor C. pubococcygeus D. corpus spongiosum E. corpus cavernosum

Q: The __________ is not a portion of the urethra. A. external urethral orifice B. internal urethral sphincter C. prostatic urethra D. membranous urethra E. spongy urethra

Q: Micturition is another term for __________. A. the production of nitrogenous wastes B. glomerular filtration C. the countercurrent multiplier process D. inflammation of the urinary bladder E. the elimination of urine

Q: The ureters pass anterior to the bladder and enter it from below.

Q: Albuminuria is a common sign of diabetes mellitus.

Q: Diseases that affect the descending corticospinal tracts may limit inhibition of the sacral somatic motor neurons and thus could result in urinary incontinence.

Q: Ethyl (drinking) alcohol stimulates the secretion of ADH, thereby reducing reabsorption by the collecting duct.

Q: Parathyroid hormone increases phosphate excretion by the proximal convoluted tubule as well as promotes synthesis of calcitriol.

Q: The countercurrent multiplier mechanism for water conservation was discovered by limiting studies to humans and thus hypothesizing how form determines function.

Q: The thick segment of the nephron loop is impermeable to water.

Q: Loop diuretics reduce body water content by acting on the __________. A. feedback loop between the kidney and posterior pituitary gland B. countercurrent multiplier system C. countercurrent exchanger system D. aquaporins of the collecting duct E. thirst mechanism and water intake

Q: Aldosterone acts on the __________. A. proximal convoluted tubule B. medullary portion of the collecting duct C. descending limb of the nephron loop D. distal convoluted tubule E. glomerulus

Q: In the thick segment of the ascending limb of the nephron loop, K+ reenters the cell from the interstitial fluid via the _________. K+ is then secreted into the tubular fluid. A. Na+-K+ pump B. countercurrent multiplier C. countercurrent exchange D. vasa recta E. juxtaglomerular apparatus

Q: Which of the following is not a method by which atrial natriuretic peptide reduces blood volume and pressure? A. Increasing glomerular filtration rate B. Inhibiting renin and aldosterone secretion C. Inhibiting the action of ADH on the kidney D. Inhibiting NaCl reabsorption by the collecting duct E. Preventing sodium loss in the urine