Hypothalamus and Posterior Pituitary Quiz

The endocrine system regulates homeostasis through feedback loops, most commonly:

Which of the following actions does not follow this regulatory pathway?

A 67-year-old man is brought to the emergency room by his daughter because of complaints of muscle weakness, lethargy, and confusion. His daughter says that these symptoms began 3 weeks ago. All vital signs are within normal limits. The physical examination shows moderate mental confusion, without abnormality in heart or lungs. There is no peripheral edema. Past history is notable only for trigeminal neuralgia starting 2 months ago, which is being treated with carbamazepine. Laboratory testing shows:

Serum basic chemistry:

• Na…………… 112.2 mEq/L
• K…………………4.5 mEq/L
• Cl……………….99.1 mEq/L
• HCO3………….24.7 mEq/L
• Glucose………..82 mg/L
• BUN…………….16 mg/L
• Creatinine……0.9 mg/L

Urine sodium……….189 mEq/L

Which of the following is the most likely cause of the patient’s symptoms?

A 35-year-old man with bipolar I disorder and HTN comes to his physician for a follow up visit. He tells his doctor that everything is “okay”. A review of systems, however, reveals that the patient is drinking water continually, has increased urinary frequency, and sleep disturbances. His brother who is visiting the office with him tells the physician that he often hears his brother get up at night to drink water.

The physical examination is unremarkable.

Laboratory testing shows: Serum sodium concentration: 145 mEq/L, potassium is 4.3 mEq/L and serum glucose 98 mg/dL. Urine osmolarity: 98 mOsm/kg H2O. Which of the following is the most likely explanation of these findings?

A 75-year-old woman visits her physician for a wellness checkup. She has a 15 year history of poorly controlled hypertension and type 2 diabetes mellitus. Current medications include hydrochlorothiazide, enalapril, metformin and spironolactone. She is poorly compliant with her medications. Laboratory testing results: serum creatinine = 2.8 gm/dL with an eGFR =  18 mL/min/1.73 m^2, blood urea nitrogen =36 mg/dL, Plasma calcium= 8.2 mg/dL. Cellular hyperplasia could be expected in which organ?