Download RENAL - ACID BASE – ADRENAL PHYSIOLOGY

RENAL - ACID BASE –
ADRENAL PHYSIOLOGY
MCQS
22nd Dec 2011
1.
Secretion of K+ by the distal tubule will be decreased by which of the
following?
a.
b.
c.
d.
2.
A woman has a plasma osmolarity of 300 mosm/. The correct diagnosis is
a.
b.
c.
d.
3.
Emphysema
Prolonged vomiting
Bicarbonate ingestion
2 week residence at high altitude
The principal buffer in interstitial fluid is which of the following?
a.
b.
c.
d.
5.
SIADH
Water deprivation
Central diabetes insipidus
Nephrogenic diabetes insipidus
The following blood gas picture is most consistent with: pH = 7.56; pCO2 =
20mmHg; pO2 = 100mmHg; bicarb = 25mmol/
a.
b.
c.
d.
4.
Metabolic alkalosis
A high K+ diet
Hyperaldosteronism
Spironolactone administration
Carbonic acid
Hb
Phosphate
Compounds containing histidine
Regarding absorption of Na+ in the proximal tubule, which of the following is
true?
a.
b.
c.
d.
The proximal tubule reabsorbs 80% of the filtered sodium load
Absorption of Na+ causes increasing hypertonicity in the tubule lumen
Absorption is powered by the Na+/H+ ATPase
Shares a common carrier with glucose
6.
Which of the following agents does not cause contraction of the mesangial
cells in the glomerulus?
a.
b.
c.
d.
Angiotensin II
Noradrenaline
Histamine
Dopamine
7.
The lower pH limit of the urine is which of the following?
a.
b.
c.
d.
8.
ADH (vasopressin) secretion is increased by which of the following?
a.
b.
c.
d.
9.
Solutes diffuse out of vessels conducting blood toward the cortex
Water diffuses out of ascending vessels
Water diffuses into the collecting ducts
Counter current exchange is passive and can operate even if counter
current multiplication ceases
Which of the following is most permeable to water?
a.
b.
c.
d.
11.
Alcohol
Carbamazepine
 extracellular fluid volume
Angiotensin I
With respect to the counter current system, which is false?
a.
b.
c.
d.
10.
1.0
3.5
4.5
6.0
Thin ascending Loop of Henle
Distal convoluted tubule
Thin descending Loop of Henle
Thick ascending limp of Loop of Henle
pH 7.16; pCO2 = 24mmHg; pO2 = 100mmHg; bicarbonate = 6mmol/; K+ =
3.4mmol/
Which of the following is MOST likely to cause the above picture
a.
b.
c.
d.
12.
Cyanide poisoning
Hyperventilation
Liquorice ingestion
Addison’s disease
Metabolic alkalosis can be caused by all of the following EXCEPT
a.
b.
c.
d.
Hyperaldosteronism
Hyperventilation
Hypokalaemia
Volume depletion
13.
The consumption of oxygen by the kidney, which is incorrect?
a.
b.
c.
d.
14.
An increase in the concentration of plasma potassium causes an increase in
which of the following?
a.
b.
c.
d.
15.
Constriction of the afferent arteriole
A decrease in afferent arteriolar pressure
Compression of the renal capsule
A decrease in the concentration of plasma protein
The greatest amount of hydrogen ion secreted by the proximal tubule is
associated with which of the following?
a.
b.
c.
d.
17.
Release of renin
Secretion of aldosterone
Secretion of ADH
Release of natriuretic hormone
Which of the following would increase GFR?
a.
b.
c.
d.
16.
Decreases as blood flow increases
Is regulated by erythropoietin
Remains constant as blood flow increases
Is greatest in the medulla
Excretion of potassium ion
Reabsorption of calcium ion
Reabsorption of bicarbonate ion
Reabsorption of phosphate ion
All of the following comparisons between the distal nephron and the proximal
tubule are correct EXCEPT
a.
b.
c.
d.
The distal nephron is less permeable to hydrogen ion than is the
proximal tubule
The distal nephron has a more negative intraluminal potential than does
the proximal tubule
The distal nephron secretes more potassium than does the proximal
tubule
The distal nephron secretes more hydrogen ion than does the proximal
tubule
18.
Urinary volume is increased by all of the following EXCEPT
a.
b.
c.
d.
19.
Which one of the following statements about aldosterone is correct?
a.
b.
c.
d.
20.
Sympathetic stimulation
Diabetes insipidus
Increased renal arterial pressure
Infusion of mannitol
It produces its effect by activating cAMP
It produces its effects by increasing membrane permeability to
potassium
It causes an increased reabsorption of hydrogen ion
It is secreted in response to an increase in BP
The ability of the kidney to excrete a concentrated urine will increase if
a.
b.
c.
d.
The permeability of the proximal tubule to water decreases
The rate of blood flow through the medulla decreases
The rate of flow through the Loop of Henle increases
The activity of the Na-K pump in the Loop of Henle decreases
21. Which of the following returns closest to normal during chronic respiratory
acidosis?
a. Arterial PCO2
b. Arterial PO2
c. Plasma concentration of bicarbonate
d. Arterial concentration of hydrogen ion
22.
Renal correction of hyperkalaemia will result in which of the following?
a.
b.
c.
d.
23.
Alkalosis
Increased secretion of HCO3Acidosis
Increased excretion of Na+
In controlling the synthesis and secretion of aldosterone – which of the
following factors is LEAST important?
a.
b.
c.
d.
Renin
Angiotensin II
ACTH
Concentration of plasma K+
24.
Ammonia is an effective and important urinary buffer for which of the
following reasons?
a.
b.
c.
d.
25.
pH 7.67, PO2 120mmHg on O2; PCO2 60mmHg and bicarbonate 36mmol/l on
a blood gas is indicative of
a.
b.
c.
d.
26.
Aquaporin -1
Aquaporin -2
Aquaporin -3
Aquaporin -4
Dehydration increases the plasma concentration of all of the following
EXCEPT
a.
b.
c.
d.
29.
75mg/min
100mg/min
150mg/min
300mg/min
A loss of function mutates in the gene of which of the following proteins is
associated with nephrogenic diabetes insipidus
a.
b.
c.
d.
28.
Respiratory alkalosis
Mixed metabolic and respiratory alkalosis
Respiratory acidosis
Metabolic alkalosis
The TMg for women (transport maximum for glucose) in the kidney is about
a.
b.
c.
d.
27.
Its production in the kidney  during chronic alkalosis
The walls of the renal tubules are impermeable to NH3
The walls of the renal tubules are impermeable to NH4+
Its acid base reaction has a low pKa
Vasopressin
Angiotensin II
Noradrenaline
Atrial natriuretic peptide
Calculate the anion gap from these results –
Na+ 142; K+ 3.5mmol/l; glucose 6mm0l/l; chloride 110mm0l/l; bicarbonate =
10mmol/l; urea = 7.0mmol/l
a.
b.
c.
d.
15
17
22
29
30.
Regarding water excretion, which is true?
a.
b.
c.
d.
At least 87% of filtered water in kidney is reabsorbed
About 5% of filtered water is removed in the distal tubule
Aquaporin -1 plays a major role in water conservation, although it is
unaffected by vasopressin
All of the above are correct
31.
H+ secretion in the distal nephron is enhanced by all of the following
EXCEPT
a.
b.
c.
d.
32.
Renin release from the juxtaglomerular apparatus is inhibited by which of the
following?
a.
b.
c.
d.
33.
Glucose
Creatinine
Bicarbonate
Phosphate
Ammonia is an effective and important urinary buffer for which of the
following reasons?
a.
b.
c.
d.
35.
 agonists
Prostaglandins
Increased pressure within the afferent arterioles
Stimulation of the macula densa
Which of the following substances will be more concentrated at the end of the
proximal tubule than at the beginning of the proximal tubule?
a.
b.
c.
d.
34.
An increase in the level of plasma aldosterone
An increase in the tubular lumen concentration of poorly reabsorbable
ions
Hyperkalaemia
Respiratory acidosis
Its production in the kidney decreases during chronic acidosis
The walls of the renal tubules are impermeable to NH3
The walls of the renal tubules are impermeable to NH4+
Its acid-base reaction has a low pKa
The following blood picture is most likely consistent with:
( Na+ = 120mmol/l, K+ = 6.7 mmol/l, chloride = 95mmol/l, bicarbonate = 20.)
a.
b.
c.
d.
Normality
1 adrenal insufficiency
1 hyperaldosteronism
Diabetes insipidus
36.
What is the glomerular filtration rate when urine flow = 1ml/minute; arterial
plasma level of inulin = 0.20mg/ml, and urine concentration of inulin is
40mg/ml?
a.
b.
c.
d.
80ml/min
150ml/min
200ml/min
400ml/min
37.
Which of the following substances is both reabsorbed +/- secreted in the
kidney?
a.
Potassium
b.
Sodium
c.
Bicarbonate
d.
Glucose
38.
Regarding renal handling of sodium, which is true?
a.
b.
c.
d.
39.
Regarding water excretion from the kidney, which is true?
a.
b.
c.
d.
40.
Sodium is reabsorbed in the proximal tubule by the Na+ /2Cl-/ K+
transporter.
Mineralocorticoids increase tubular reabsorption of sodium.
Sodium excretion is decreased by drugs that decrease renal acid
secretion by inhibiting carbonic anhydrase.
Overall = 90% of sodium filtered at the glomerulus is reabsorbed.
Aquaporin 2 – is found in the cells of the thin ascending loop of Henle.
At least 67% of filtered water is absorbed – even when urine volume is
very high.
The ascedning limb of the loop of Henle is impermeable to water.
When vasopressin is absent – the collecting duct epithelium is
permeable to water.
Which of the following is false with respect to angiotensins?
a.
b.
c.
d.
Angiotensin I’s sole action is as a precursor of Angiotensin II
Angiotensin II is 4 to 8 times most potent vasoconstrictor than
noradrenaline
Patients with cirrhosis are less responsive to Angiotensin II
Angiotensin III has less aldosterone stimulating effect than Angiotensin
II
41. Regarding buffers in body fluids which is false?
a. H2PO4- is a major buffer in the blood
b. bicarbonate is a principal buffer in interstitial fluid
c. proteins are important buffers in intracellular fluid
d. proteins are one of the major buffers in the blood
42. Regarding pH of body fluid which is true?
a. gastric acid pH is around 3.0
b. pancreatic secretion pH is around 5.0
c. plasma pH is normally around 7.0
d. urine can sometimes be as acidic as a pH of 4.5
43. Renal acid secretion is altered by a change in which of the following?
a. partial pressure of CO2
b. concentration of serum potassium
c. level of carbonic anhydrase
d. all of the above
44. Regarding ammonia secretion which is false?
a glutaminase enzyme helps facillitate ammonia secretion
b. glutamic dehydrogenase helps facillitate ammonia secretion
c. the amount of ammonium ion excreted is reduces as urine pH increases
d. non-ionic diffusion is process by which the NH4+ concentration gradient is
maintained across the tubules
45. Which of the following is true of the renal secretion of H+?
a. facilitated by renal tubular bicarbonate, ammonia and H2PO4b. occurs via the sodium, hydrogen antiport in the interstial border of
proximal tubule cells
c. all of the above
d. none of the above
46. What stimulates Vasopressin (ADH) secretion?
a.
b.
c.
d.
Increased osmotic pressure of plasma
Decreased ECF volume
Angiotensin II
All of the above
47. What decreases Vasopressin secretion?
a. Alcohol
b. Standing
c. Carbamezepine
d. Nausea & vomiting
48. Renin secretion is increased by which of the following?
a. Vasopressin (ADH)
b. Angiotensin II
c. catecholamines
d. hypertension
49. Which is true in regards to Angiotensin?
a. Its precursor, Angiotensinogen, is produced by the Adrenals.
b. Is inactive in its Angiotensin III form.
c. It stimulates both aldosterone & vasopressin release
d. Is most active as Angiotensin I
50. What is true regarding erythropoietin?
a. 85% comes from the kidneys, the remainder from the liver.
b. Has a half life of 5hrs, but its effect takes 2-3 days to appear.
c. As plasma haematocrit decreases, the erythropoietin level increases in a
linear fashion.
d. All of the above
51. Which of the following causes relaxation of mesangial cells in the glomerulus?
a.
b.
c.
d.
Endothelins
Angiotensin II
Noradrenalin
Dopamine
52. Regarding substances used for the measurement of GFR which of the following is
false?
a.
b.
c.
d.
Must be readily secreted and reabsorbed in the tubules
Must not be metabolised
Must be non-toxic
Must be freely filtered in the glomerulus
53. As stimulation of the renal nerves increases which of the following is false?
a.
b.
c.
d.
Renin secretion is increases
Na+ reabsorption is increases
GFR increases
Sensitivity of the JG cells increases
54. Where is Na+ reabsorbed in the largest quantities?
a.
Proximal tubule
b.
Thick ascending loop of Henle
c.
Distal convoluted tubule
d. Collecting ducts
55. In which portion of the nephron does Aldosterone regulate sodium absorption?
a.
b.
c.
d.
Proximal tubule
Thick ascending loop of Henle
Distal convoluted tubule
Collecting ducts
56. Which is true regarding the nephron?
a. the glomerular basement membrane allows free passage of all substances
less than 4mm
b. the nephron is 200um in diameter
c. podocytes form filtration slits 25nm wide
d. glomerular capillary endothelium has pores 200nm in diameter
57. With respect to cellular function in the kidney, which is false?
a. juxtaglomerular cells secrete rennin
b. I cells secrete prostagladins
c. mesangial cells take up immune complexes
d. P cells are involved in ADH-stimulated water reabsorption
58. Which is true regarding renal blood flow?
a. a high protein diet increases renal blood flow
b. Angiotensin II and dopamine increases renal blood flow
c. protagladins decrease cortical blood flow
d. noradrenaline constricts efferent arterioles
59. Which is false with respect to renal blood flow?
a. the medulla is vulnerable to hypoxia
b. medullary flow is greater than cortical flow
c. cortical PO2 = 50 mmHg
d. clearance of PAH = 630 ml/min
60. Which of the following relaxes mesangial cells?
a. Angiotensin II
b. PGF2
c. PGE2
d. Histamine
61. Which of the following is not secreted by the tubules?
a. creatinine
b. uric acid
c. potassium
d. sodium
62. What is the renal threshold for glucose in men?
a. 375 mg/min
b. 300 mg/dL
c. 180 mg/dL
d. 300 mg/min
63. Regarding permeability and transport in the nephron, which is false?
a. the thin portion of the loop of Henle is impermeable to Na+
b. the thick ascending limb is impermeable to water
c. the tubular fluid is isotonic to plasma at the end of the loop of Henle
d. most water and Na+ reabsorption occurs in the proximal convoluted tubule
64. Which of the following does not increase Na+ excretion?
a. ANP
b. Angiotensin II
c. increased GFR
d. PGE2
65. Which is true regarding K+ excretion?
a. rate of excretion is proportionate to rate of flow of tubular fluid
b. Most K+ excretion occurs in the proximal tubules
c. it is decreased when Na+ concentration is high in the distal tubule
d. it is decreased when H+ secretion is decreased
66. Which is incorrect regarding mechanism of action of some diuretics?
a. Spironolactone – inhibits action of aldosterone in collecting ducts
b. amiloride – inhibits ENaCs in collecting ducts
c. frusemide – inhibits Na-K-2Cl channels in the thick ascending Loop of
Henle
d. Thiazides – inhibits Na-H exchange in proximal convoluted tubule
67. Regarding body fluid composition, which is true?
a. Phosphates are more abundant in plasma than in intracellular fluid
b. Cl- is the dominant anion in intracellular fluid
c. Proteins tend to have a negative charge at physiologic pH
d. Extracellular fluid constitutes 40% if the total body weight
68. Which of the following is true with respect to buffers and fluid/solute movement?
a. The buffering capacity of an acid is best when its pKa is higher than the pH of
the solution
b. Fick’s law states diffusion is inversely proportionate to the cross-sectional
area
c. Osmolarity if affected by the volume of the various solutes in the solution
d. Because of glucose metabolism, infusion of 5% glucose has the net effect of
infusing a hypertonic solution
69. During replication, which is incorrect?
a. During mitosis, separation of the DNA is catalysed by DNA polymerase
b. In RNA, uracil replaces the thymine in DNA
c. Transcription is the production of RNA from DNA
d. Translation is catalysed by RNA polymerase
70. Which of the following is a nutritionally essential amino acid?
a. Arginine
b. Alanine
c. Glutamine
d. Tyrosine
71. Which is incorrect regarding plasma lipids?
a. Free fatty acids can circulate as lipoproteins bound to albumin
b. The endogenous pathway transports lipoproteins from the intestine to the
liver
c. Exogenous ingested lipids are transported by chylomicrons
d. Lipoprotein lipase requires heparin as a cofactor
72. Regarding buffering systems which is correct?
a. Carbonic anhydrase is found in high concentrations in the gastric-acid
secreting cells and the renal tubular cells
b. Haemoglobin acts as a buffer
c. In a respiratory acidosis and alkalosis, buffering is almost all intracellular
d. All of the above are correct
73. Regarding the Siggaard-Andersen curve nomogram, which is correct?
a. The nomogram plots total CO2 concentration against pH
b. Higher Hb concentrations cause a loss of buffering ability
c. The buffer base is equal to the total number of buffer anions
d. The Base Excess is positive in acidosis
74. Renal acid secretion is enhanced by which of the following factors?
a. High PCO2, Low K+, Aldosterone activity
b. High PCO2, High K+, Aldosterone activity
c. Low PCO2, Low K+, Aldosterone inhibition
d. High PCO2, Low K+, Aldosterone inhibition
75. Regarding compensatory mechanisms for acid-base disturbance, which is
incorrect?
a. HCO3- is reabsorbed in exchange for H+
b. Cations are lost producing diuresis with low acid loads
c. The limiting urinary pH is about 4.5
d. Respiratory compensation of a metabolic alkalosis is limited by the
mechanisms of the carotid and aortic chemoreceptors
76. With regard to ammonia secretion, which is false?
a. Ammonia is very water soluble so diffuses into urine along its concentration
gradient
b. In chronic acidosis, the amount of excreted ammonia decreases
c. The process of ammonia secretion into the urine is called ionic diffusion
d. All of the above
77. Which of the following is correct regarding Na+ handling in the kidney:
a. 60% is reuptaken in the Collecting ducts
b. The Na-K-2Cl cotransporter is present in the thick ascending loop
c. Aldosterone mainly affects Na+ transport in the PCT
d. The majority of filtered Na+ is not reabsorbed
78. When measuring GFR using Inulin, if Urine flow is 1ml/min, Plasma inulin
concentration is 0.25mg/ml and Urine inulin concentration is 30mg/ml, the GFR is:
a. 120ml/min
b. 12ml/min
c. 7.5ml/min
d. 30ml/min
79. Which of the following factors and its effect on renal blood flow is correctly
paired?
a. Noradrenaline: Increases RBF
b. Acetylcholine: Decreases RBF
c. Angiotensin II: Decreases RBF
d. Dopamine: Decreases RBF
80. Regarding Glucose handling in the kidney, which is true?
a. 50% of filtered glucose is reabsorbed
b. Glucose is transported together with Na+
c. There is no threshold for the amount of Glucose that can be absorbed per
unit volume
d. The main transport of Glucose occurs in the DCT
81. The effect of salt and water concentration in the Thick ascending Loop on the
Renal arteriolar pressure is called:
a. Autoregulation
b. Glomerulotubular balance
c. Splay
d. Tubuloglomerular feedback
82. Principle buffers in the blood include all EXCEPT:
a. Sodium
b. Bicarbonate
c. Protein
d. Haemoglobin
83. Match pH with it’s correct fluid:
a. Gastric HCl – pH 5.0
b. Pancreatic juice – pH 8.0
c. Maximal urine acidity – pH 4.0
d. Normal plasma – pH 7.2
84. Which of the following is true with regards to urinary pH changes:
a. pH of urine varies from 4.0 to 9.0
b. For each H+ ion excreted there is a net gain of 2 HCO3- ions
c. Has implications for the body’s electrolyte and acid-base economy.
d. When base is added to the body fluids, the HCO3- ions are buffered
raising the plasma OH-.
85. In respiratory acidosis:
a. There is a reduction in arterial PCO2 caused by increased ventilation.
b. the interior of cells become less acidic with increased PCO2
c. Renal tubular H+ secretion is decreased.
d. HCO3- reabsorption is increased.
86. In metabolic acidosis:
a. The plasma pH is high
b. The plasma HCO3- is low
c. The arterial pCO2 remains high
d. The plasma pH, HCO3- and pCO2 are all high
87. Regarding vasopressin, which is false?
a. All vasopressin receptors are G-coupled
b. It increases expression of aquaporin-1 channels in the collecting ducts
c. Haemorrhage is a potent stimulus for secretion
d. V1a receptors are also found in the liver and brain
88. Which of the following increases vasopressin secretion?
a. Decreased osmotic pressure of plasma
b. Increased ECF volume
c. Nausea and vomiting
d. Alcohol
89. Which of the following does not increase renin secretion?
a. Cirrhosis
b. Cardiac failure
c. Diuretics
d. Lying down
90. In the kidney, erythropoietin is secreted by:
a. Cells in the peritubular capillary bed
b. Cells in the distal tubules
c. Cells in the proximal tubules
d. Cells in the macula densa
91. Dehydration increases plasma concentration of all of the following except?
a. Aldosterone
b. Angiotensin II
c. Vasopressin
d. ANP