Question

Case 1:

This patient presented with thirst, polyuria and polydipsia.Studies show the following lab results:

Lab Measurement	Patient Results	Normal Range
Serum Glucose	100mg/dL
Serum Sodium	146mM
Serum BUN	22mg/dL
Hemoglobin	17.2g/dL
Hematocrit	51%
Urinary sodium	77mM/day
Serum creatinine	1.0mg/dL
Serum uric acid
Serum potassium	4.8mg/dL
Serum insulin	WNL
Plasma renin activity	Low
Plasma osmolality	308mOsm/kg
Urine osmolality	250mOsm/kg

Amanda R. is a 20-year-old junior in college. Beginning about amonth ago, she noticed that she was waking up once, sometimes twicea night, to go to the bathroom. More recently she has noticed thatshe needs to go to the bathroom during her school day much morefrequently than before, sometimes as often as once every hour.

Her mother insisted that she go see the family physician. Noabnormalities were found on physical examination. Amanda had nohistory of traumatic head injury and an MRI of her brain wasnormal. Next, a 2-h water deprivation test was performed on Amanda.After two hours of not being able to drink water, the osmolarity ofher plasma and urine was measured a second time. This time herurine osmolarity was unchanged but the osmolarity of the plasmaincreased to 315mOsm/kg.

Based on the results, explain the problem that Amanda ishaving.

Question 1

Describe the mechanisms by which normal fluid regulation in thebody occurs?

Question 2

What is the possible treatment of this disease?

Question 3

What other conditions cause polyuria and polydipsia?

Please answer question 1,2,3 and explain