Chloride homeostasis is regulated as a side effect of sodium homeostasis. True False
A buffer system converts a weak acid or base into a strong one. True False
The three physiological buffer systems are urinary, digestive, and respiratory. True False
The kidneys neutralize more acid or base than any other buffer system.
Acidosis is a pH lower than 7, whereas alkalosis is a pH higher than 7.
Uncompensated alkalosis is a pH imbalance that can only be corrected with clinical intervention.
Most of the body water is in
A. the intracellular fluid (ICF). B. the extracellular fluid (ECF). C. tissue (interstitial) fluid. D. blood plasma and lymph. E. the transcellular fluid.
A. the intracellular fluid (ICF).
Osmosis from one fluid compartment to another is determined by 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. blood pressure.
B. the relative concentration of solutes in each compartment.
In which of these compartments would fluid accumulate in edema?
A. intracellular fluid (ICF) B. transcellular fluid C. tissue (interstitial) fluid D. blood plasma E. lymph
C. tissue (interstitial) fluid
Most body water comes from _____, whereas most body water is lost via ___.
A. metabolic water; cutaneous transpiration B. metabolic water; sweat C. drinking; cutaneous transpiration and expired air D. drinking; urine E. drinking; radiation
D. drinking; urine
Fluid intake is governed mainly by hypothalamic neurons called
A. baroreceptors. B. proprioceptors. C. nociceptors. D. osmoreceptors. E. mechanoreceptors.
Antidiuretic hormone (ADH)
A. stimulates angiotensin II secretion. B. promotes water conservation. C. stimulates hypothalamic osmoreceptors. D. inhibits salivation and thirst. E. targets the cerebral cortex.
B. promotes water conservation.
Water output is significantly controlled through variations in
A. metabolic water. B. sweating. C. cutaneous transpiration. D. drinking. E. urine volume.
E. urine volume.
When blood volume and pressure are too high A. ADH release is inhibited. B. ADH release is stimulated. C. renal tubules reabsorb more water. D. renal tubules reabsorb more sodium. E. the kidneys produce less urine.
A. ADH release is inhibited.
Prolonged exposure to cold weather can lead to
A. fluid sequestration in the upper limbs. B. hypotonic hydration. C. hypovolemia. D. a positive water balance. E. a negative water balance.
E. a negative water balance.
Dehydration results in increased blood and ECF osmolarity. This makes osmoreceptors stimulate ____ secretion by the hypothalamus ____ in the DCT and CD.
A. ADH; decreasing water reabsorption B. ADH; increasing water reabsorption C. aldosterone; decreasing sodium and water reabsorption D. aldosterone; increasing sodium and water reabsorption E. angiotensin II; increasing sodium reabsorption
B. ADH; increasing water reabsorption
Hemorrhages A. decrease body water but do not significantly affect osmolarity. B. decrease body water but increase osmolarity. C. decrease body water and decrease osmolarity. D. increase ECF volume but decrease ICF volume. E. decrease ECF volume but increase ICF volume.
A. decrease body water but do not significantly affect osmolarity.
Long-term inhibition of thirst is mostly associated with 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.
C. a drop in blood osmolarity.
This is the principal cation of the ECF. A. Ca2+ B. Cl- C. K+ D. Na+ E. Pi
Aldosterone receptors are found on cells of A. the adrenal cortex. B. the adrenal medulla. C. the posterior pituitary. D. the proximal convoluted tubule (PCT). E. the distal convoluted tubule (DCT).
E. the distal convoluted tubule (DCT).
Aldosterone A. increases both Na+ and K+ reabsorption. B. increases both Na+ and K+ secretion. C. increases Na+ reabsorption and K+ secretion. D. reduces Na+ reabsorption and K+ secretion. E. causes the urine to be more diluted.
C. increases Na+ reabsorption and K+ secretion.
Hypernatremia is a plasma ___ concentration above normal.
A. Ca2+ B. Na+ C. K+ D. Cl- E. Pi
Hypernatremia tends to cause all of the following except
A. water retention. B. edema. C. hypertension. D. interstitial fluid accumulation. E. a reduction in plasma volume.
E. a reduction in plasma volume.
_____ is the most significant solute in determining the distribution of water among fluid compartments.
A. Na+ B. Cl- C. Ca2+ D. K+ E. Pi
___ does not stimulate aldosterone secretion.
A. Hypotension B. Hyponatremia C. Hyperkalemia D. High blood sodium concentration E. High blood potassium concentration
D. High blood sodium concentration
Women have a tendency to retain water during part of the menstrual cycle because estrogen mimics the action of
A. ADH. B. aldosterone. C. atrial natriuretic hormone. D. oxytocin. E. prolactin.
This is the most abundant cation of the ICF. A. Ca2+ B. Na+ C. K+ D. Cl- E. Pi
The total body water (TBW) content of a 70 kg young male is about
A. 10 L. B. 20 L. C. 40 L. D. 60 L. E. 70 L.
C. 40 L.
This is the greatest determinant of intracellular volume.
A. K+ B. Na+ C. Ca2+ D. Cl- E. PO43-
These scenarios are related with hyperkalemia except
A. cells are more excitable. B. resting membrane potential is more negative. C. cells are partially depolarized. D. cells are more sensitive to stimulation. E. there is less diffusion of potassium out of the cells.
B. resting membrane potential is more negative.
In a state of hypokalemia
A. cells are partially depolarized. B. there is more diffusion of potassium into the cells. C. cells are more excitable. D. resting membrane potential is more positive. E. cells are hyperpolarized.
E. cells are hyperpolarized.
Hypokalemia can result from all of the following except from
A. chronic vomiting. B. diarrhea. C. heavy sweating. D. aldosterone hyposecretion. E. excessive use of laxatives.
D. aldosterone hyposecretion.
This is the most abundant anion of the ECF. A. HCO3- B. PO43- C. HPO42- D. H2PO4- E. Cl-
Chloride homeostasis is achieved mainly as a result of ___ homeostasis. A. H2PO4- B. PO43- C. HCO3- D. Na+ E. K+
The calcium of the body fluids
A. participates in muscle contraction. B. is not a significant component of nucleic acids. C. serves as a second messenger. D. activates exocytosis. E. is not important in blood clotting.
B. is not a significant component of nucleic acids.
Calcium concentration is regulated by A. hormones. B. sodium and calcium concentration in plasma. C. chloride and phosphate concentration in plasma. D. the parasympathetic nervous system. E. the sympathetic nervous system.
The inorganic phosphates (Pi) of the body fluids A. are not a significant component of nucleic acids. B. are not important for cell membrane structure. C. are not necessary in the linking of endergonic with exergonic reactions. D. form crystals with calcium in the presence of calsequestrin. E. participate in the activation of some enzymes.
D. form crystals with calcium in the presence of calsequestrin.
Excretion of phosphate A. increases free potassium ions in the ECF. B. increases free calcium ions in the ECF. C. increases free chloride ions in the ICF. D. decreases free potassium ions in the ECF. E. decreases free calcium ions in the ECF.
B. increases free calcium ions in the ECF.
___ represents the complete chemical reaction for the bicarbonate buffer system. A. CO2 + H2O H2CO3 HCO3- + H+ B. CO2 + H2O HCO3- + H+ H2CO3 C. H2CO3 CO2 + H2O HCO3- + H+ D. H2CO3 HCO3- + H+ E. CO2 + H2O HCO3- + H+
A. CO2 + H2O H2CO3 HCO3- + H+
Tissue fluid normally has a pH of 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
The major chemical buffers systems of the body are the ___ systems. A. urinary and respiratory B. urinary and digestive C. bicarbonate, phosphate, and protein D. bicarbonate, nucleic acids, and protein E. bicarbonate, phosphate, and nitrate
C. bicarbonate, phosphate, and protein
What protein(s) is/are the most important buffer(s) in blood plasma? A. fibrinogen B. albumin C. alpha globulins D. gamma globulins E. transferrin
What protein(s) is/are the most important buffer(s) in erythrocytes? A. albumin B. fibrinogen C. gamma globulins D. hemoglobin E. myoglobin
A weak base A. binds little OH- and has a weak effect on pH. B. binds lots of OH- and has a strong effect on pH. C. binds little H+ and has a weak effect on pH. D. resists changes in OH-. E. lowers the pH.
C. binds little H+ and has a weak effect on pH.
When the renal tubules secrete hydrogen ions into the tubular fluid, they ___ at the same time. A. secrete potassium B. secrete sodium C. reabsorb potassium D. secrete chloride E. reabsorb sodium
E. reabsorb sodium
The pH of the intracellular fluid is buffered mainly by A. proteins. B. the bicarbonate system. C. the phosphate system. D. the carbonic acid system. E. ammonium ions.
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.
E. expels CO2 produced by the buffer system.
An antiport system on the basal side of renal tubule cells A. transports bicarbonate from the tubular fluid back into the tubule cells. B. transports H+ in both directions across the epithelium. C. transports CO2 from the blood into the tubule cells. D. exchanges K+ for Na+. E. exchanges H+ for Na+.
D. exchanges K+ for Na+.
Proteins can buffer a drop in pH by their _____ side groups and can buffer an increase in pH by their _____ side groups. A. -NH2; -PO4 B. -PO4; -COOH C. -NH2; -COOH D. -COOH; -NH2 E. -PO4; -NH2
C. -NH2; -COOH
In a person with normal acid-base balance, there are no bicarbonate ions in urine because A. they are consumed by neutralizing H+. B. they are reabsorbed by the renal tubule cells. C. they are exchanged for CO2. D. they are exchanged for Cl-. E. they rapidly diffuse into the renal tubule cells.
A. they are consumed by neutralizing H+.
In acidosis, the membrane potential of nerve cells is ___, which ___ the central nervous system. A. repolarized; inhibits B. depolarized; stimulates C. hyperpolarized; depresses D. depolarized; depresses E. hyperpolarized; stimulates
C. hyperpolarized; depresses
In acidosis, the kidneys compensate by A. secreting more bicarbonate. B. secreting more ammonia. C. secreting more sodium. D. reabsorbing more hydrogen ions. E. reabsorbing more ammonia.
B. secreting more ammonia.
Breathing with the head inside a plastic bag can lead to A. metabolic alkalosis. B. metabolic acidosis. C. urinary alkalosis. D. urinary acidosis. E. respiratory acidosis.
E. respiratory acidosis.
Excessive intake of antacids can lead to A. metabolic alkalosis. B. metabolic acidosis. C. respiratory alkalosis. D. respiratory acidosis. E. digestive alkalosis.
A. metabolic alkalosis.
Chronic vomiting can lead to A. metabolic acidosis. B. metabolic alkalosis. C. respiratory alkalosis. D. respiratory acidosis. E. lymphatic alkalosis.
B. metabolic alkalosis.
Emphysema can lead to A. metabolic acidosis. B. metabolic alkalosis. C. respiratory alkalosis. D. respiratory acidosis. E. digestive alkalosis.