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An 18-year-old girl is involved in a traffic accident resulting in head trauma and intracerebral hemorrhage. She undergoes extensive
rehabilitation and her neurological and mental status improve. At present, she presents with complaints of polydipsia, polyuria and nocturia,
and frequent daytime napping. On examination, no signs or symptoms of significant dehydration are found. Her glucose tolerance test and
urine analysis are normaI. Serum osmolality is 316 mOsmoI/kg, and her urine osmolality is 136 mOsmoI/kg.
Question 1 of 5
Which of the following is the most likely cause of polyuria in this patient?
/ A. ADH deficiency
/ B. Compulsive water drinking (psychogenic polydipsia)
/ C. Iatrogenic polydipsia
/ D. Increased metabolism of ADH
/ E. Lithium therapy

Question 2 of 5
Which of the following would produce polyuria via a mechanism of action most similar to the mechanism of the disease process in this
patient?
/ A. Ethanol
/ B. Hyperosmolality
/ C. Hypotension
/ D. Lithium
/ E. Nausea
Question 3 of 5
Which of the following vasopressin receptors most likely mediates vasopressin's antidiuretic action?
/ A. AQP6
/ B. Oxytocin receptor
/ C. V1a
/ D. V1b
/ E. V2

Question 4 of 5
The principal target of vasopressin actions in the kidney is water permeability of the collecting ducts. Which of the following water channel
proteins is the mediator of this vasopressin effect?
/ A. Aquaporin 0 (AQP0)
/ B. AQP1
/ C. AQP2
/ D. AQP3
/ E. AQP5


Question 5 of 5
Which of the following is the most appropriate pharmacotherapy?
/ A. Carbamazepine
/ B. Chlorpropamide
/ C. Desmopressin (DDAVP)
/ D. Hydrochlorothiazide
/ E. Indomethacin (NSAIDS)

A
D
E
?
C

D,D,E,C,C

1.A
2.D
3.E
4,A?
5.C

1.A
2.D
3.E
4.C ;AQP2
5.C

Head trauma ,plus symptoms,decreased Uosm =Cenntral DI-deficiency or absent ADH...Rx give what is deficient and that is vassopresin -Desmopressin(DDVP)..

a
d
e
??
c

A, C, E, ?, C

A

A

E

??????????????????

C

A, B, E, C,C.
answer is aquaporin 2. check this website.
http://arjournals.annualreviews.org/doi/...l.60.1.199