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1) A 30- year- old female presents with headache and blurry vision. Her blood pressure is 200/90 mm Hg. Imaging reveals that he she has a tumor that is overproducing the hormone most responsible for regulating salt and water balance  for blood pressure control. That hormone is-

a) Growth hormone

b) Glucocorticoid

c) Aldosterone

d) Epinephrine

e) Glucagon

Answer- The right answer is-c)- Aldosterone.

Aldosterone increases Na+ absorption in the kidney, and water is also reabsorbed resulting in an increase in blood volume and blood pressure. Growth hormone stimulates release of insulin like growth factors  and is responsible for growth and development. Glucocorticoids are important in response to stress. Epinephrine is the “fight or flight” hormone that stimulated glycogenolysis and lipolysis. Glucagon is the hormone to increase blood glucose levels during periods of fasting and starvation.

2) A 60-year-old female presents with severe back pain for the past one week. Imaging reveals a compression fracture of one of the vertebrae and diffuse osteoporosis, which is a common condition resulting from calcium depletion in bones. As a treatment she should be prescribed-

a) Oxytocin

b) Parathyroid hormone

c) Estradiol

d) Calcitonin

e) Prolactin

Answer- The right answer is-d)- Calcitonin. Calcitonin inhibits release of calcium from bone and also decreases blood calcium levels. Calcium, vitamin D and Calcitonin may be prescribed to help treat osteoporosis. Parathyroid hormone promotes calcium and phosphate mobilization from bone, increasing calcium levels. Oxytocin, Prolactin and Estradiol are not significant for calcium level regulation

3) A 16-year-old female presents with a fever, productive cough and rust colored sputum. She is diagnosed with bacterial pneumonia. She is a known case of type 1 Diabetes mellitus. She injects herself subcutaneously every day with exogenous insulin. As insulin is absorbed into her blood it binds to insulin receptors that activate-

a) Tyrosine kinase

b) Adenylate cyclase

c) c AMP

d) Protein kinase C

e) Phospholipase C

Answer- The right answer is -a)- Tyrosine Kinase. Insulin binds to a cell surface receptor that acts as a Tyrosine kinase. Hormones such as epinephrine and Glucagon activate Adenylate cyclase which converts ATP to cAMP. Hormones such as Thyrotropin- releasing hormone(TRH) and Oxytocin activate protein kinase C. Phospholipase C acts on Phosphatidyl Inositol (membrane Phospholipid) to cleave it to Inositol triphosphate and diacylglycerol .

4) An intern is scrubbing into a complicated surgery that is anticipated to last for 15 hours. In preparation, the intern has not eaten from the past 15 hours. After 30 hours  of fasting which of the following is most important for maintenance of normal blood glucose ?

a) Glycogenolysis

b) Gluconeogenesis

c) Triacylglycerol synthesis

d) Increased insulin release

e) Decreased muscle protein break down

Answer- The right answer is b)- Gluconeogenesis. Approximately 2-3 hours after a meal, the liver maintains normal blood glucose level by glycogenolysis. Within 30 hours liver glycogen stores are depleted, leaving gluconeogenesis as the primary source for maintaining blood glucose levels. ketone bodies are generated, triacylglycerols are broken down and muscle protein breakdown increases.

 In the fed state, insulin is the main hormone while in the fasting state, glucagon level increases.

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