Review

Question 1

To what receptors do sulfonylureas like glyburide bind?

Answer 1

SUR1 receptors in potassium ATP-dependent channels located on pancreatic beta cells

Block these channels, causing depolarization that induces insulin release

Question 2

Typical metabolic derangements associated with type 1 diabetes would result in an increase in:
A. Lipogenesis
B. Glycogen synthesis
C. Gluconeogenesis
D. Glycolysis

Answer 2

C. Gluconeogenesis

Insulin opposes gluconeogenesis, so in type 1 diabetes there will be an increase in glucagon levels and gluconeogenesis due to a lack of insulin

Question 3

What type of hypersensitivity reaction is type 1 diabetes?

Answer 3

Type IV - Though there are anti-insulin antibodies present, these do not cause the disease but are reflective of beta cell destruction by CD 8+ T cells

Question 4

Fundoscopic exam

Answer 4

Visualization of the retina using an ophthalmoscope

Importance for diagnosing diabetic retinopathy

Question 5

An 82-year-old with type 2 diabetes is brought to the ER with fever, confusion, and an infected ulcer on his toe. He has been urinating a lot lately and was gradually getting fatigued and sleepy. In the ED he is drowsy and disoriented and his oral mucosa is dry. Urine analysis reveals dipstick is 4+ for glucose. His serum sodium is 125 and his glucose is 1000. Which of the following findings would be most consistent with his diagnosis?
A. Urine dipstick 4+ for ketones
B. Decreased plasma osmolarity
C. BUN:Cr ratio >20:1
D. Elevated total body potassium stores

Answer 5

C. BUN:Cr ratio >20:1

Patient is presenting with HHS - insulin deficiency and resulting very high serum glucose increases serum osmolarity, with diuretic effect

Dehydration results in prerenal azotemia

Question 6

A nine-year-old is evaluated for short stature. Examination of the growth chart shows the child is staying on the percentile though it is a low one. Their percentile matches the predicted target height. What is the cause of this pattern of growth?

Answer 6

Familial short stature

Question 7

A 14-year-old female is evaluated for short stature. She reports difficulty concentrating and her grades have been poor. She is also troubled by constipation. Her growth chart demonstrates that she has fallen off her percentile. Her skin is dry and shallow. What is the most likely diagnosis?
A. Growth hormone deficiency
B. Familial short stature
C. Acquired hypothyroidism
D. Cushing syndrome
E. Constitutional delay of growth

Answer 7

C. Acquired hypothyroidism

Clinical story suggests hypothyroidism

Question 8

What is the most common structural change in the heart of patients with acromegaly?

Answer 8

Left ventricle hypertrophy

Question 9

Hypothalamic tumors almost always caused pituitary hyper or hypo function?

Answer 9

Hypothalamic tumors almost always caused pituitary HYPOfunction

Question 10

Which of the following is most consistent with thyrotoxicosis?
A. Wide pulse pressure
B. Coarse skin
C. Constipation
D. Weight gain

Answer 10

A. Wide pulse pressure - Reflects increased systolic blood pressure due to increased stroke volume, and decreased diastolic blood pressure due to decreased peripheral resistance

All others are signs of hypothyroidism

Question 11

A 34-year-old woman presents to the office concerned about visual changes. She appears anxious and reports she unintentionally lost 10 pounds in one month. Her palms are sweaty. She has an obvious lid lag and proptosis. Neck examination reveals a diffusely enlarged nontender thyroid. Labs revealed elevated free thyroxine and low TSH. Which of the following is most likely?
A. Autonomous hyperfunctioning nodule
B. Antibody to thyroglobulin
C. Dietary goiterogen ingestion
D. TSH receptor antibody
E. Antibody to thyroid peroxidase

Answer 11

D. TSH receptor antibody - proptosis is specific to Graves’ disease

Antibody it thyroglobulin and TPO are seen in Hashimotos thyroiditis; dietary goiterogen would cause hypothyroidism

Question 12

A patient taking estrogen containing oral contraception has increased plasma levels of thyroxine binding globulin (TBG). If the patient is euthyroid how will total T4 and free T4 levels be affected?

Answer 12

High total T4, normal free T4

TBG is produced in the liver and its synthesis is upregulated by estrogen. An increase in TBG may result in an increase in total T4 and T3 without an increase in hormone activity in the body.

Question 13

An increase in which of the following is most specific for neuroblastoma?
A. Urine catecholamines
B. Serum corticosterone
C. Serum ACTH
D. Urine vanillylmandelic acid
E. Urine 24 hour free cortisol

Answer 13

D. Urine vanillylmandelic acid (VMA)

Neuroblastoma – poorly differentiated neoplasm derived from neural crest cells, originate in the adrenal medulla most commonly

*vanillylmandelic acid (VMA) and homovanillic acid (HVA)* are breakdown products of catecholamines - presence in urine is diagnostic of neuroblastoma

Question 14

A 37-year-old male presents to the office concerned about recent onset of headaches, palpitations, and diaphoresis (sweating). Cutaneous pallor is noted. BP is 190/120 initially, then 150/90 15 minutes later. His metabolic panel is normal. Elevation in which of the following would help confirm the diagnosis?
A. Plasma renin
B. Aldosterone
C. ACTH
D. Plasma metanephrines
E. Parathyroid hormone

Answer 14

D. Plasma metanephrines

Patient is presenting with pheochromocytoma originating from the adrenal medulla (neural crest cells)

Metanephrines are the enzymatic metabolites of catecholamines via the action of COMT (catechol-O-methyltransferase)

Question 15

Which of the following best describes the mechanism of action of cinacalcet?
A. Incorporate into bone matrix and blocks osteoclast activity
B. Activates calcium sensing receptors in the parathyroid gland
C. Binds to and prevents the action of RANK-L
D. Increases calcium absorption in the intestine

Answer 15

B. Activates calcium sensing receptors in the parathyroid gland

Question 16

A 69-year-old man presents to the office complaining of fatigue, weakness, bone pain, and weight loss. PMH is significant for COPD and smoking history. He appears ill and thin. There are decreased breath sounds at the left base. Serum calcium is markedly elevated and PTH levels are undetectable. Which of the following is most likely true?
A. Serum levels of PTHrP are elevated
B. He has diffuse lytic bony metastasis
C. He has a mutation in the calcium sensing receptor
D. His serum phosphate levels are high

Answer 16

A. Serum levels of PTHrP are elevated

Patient has PTH – independent hypercalcemia due to squamous cell carcinoma of the lung (which produces PTHrP)

Question 17

Carpal spasm (sustained tonic muscle contractions) is associated with:
A. Alkalemia and low ionized calcium
B. Acidemia an elevated ionized calcium


Answer 17

A. Alkalemia and low ionized calcium

Muscle spasms associated with LOW Ca2+

Question 18

How does alkalosis affect calcium levels?

Answer 18

Drop in plasma hydrogen causes hydrogen to leave its binding sites on albumin, making more free sites for calcium to bind – this will acutely decrease the levels of the biologically active ionized calcium

Question 19

What is the clinical use of ergocalciferol?

Answer 19

Ergocalciferol = vitamin D2

Used to treat vitamin D deficiency - note this still must be converted to active form (calcitriol) via 1-hydroxylase (in the kidney)

Question 20

What is the most common cause of mild hypercalcemia with a normal serum albumin level (otherwise asymptomatic)?

Answer 20

Benign parathyroid adenoma, causing primary hyperparathyroidism

Question 21

A 49-year-old woman presents for her annual gynecological exam. She reports oligomenorrhea over the past several months and onset of night sweats. Which of the following raise a major concern regarding her bone health?
A. Rising plasma GH, falling plasma FSH
B. Rising plasma cortisol, falling plasma estradiol
C. Rising plasma FSH, falling plasma estradiol

Answer 21

C. Rising plasma FSH, falling plasma estradiol

Question 22

Which of the following is induced by cortisol in skeletal muscle cells?
A. increased glucose utilization
B. Decreased sensitivity to insulin

Answer 22

B. Decreased sensitivity to insulin

Cortisol promotes elevated glucose levels in the blood by decreasing glucose uptake in muscle and adipose

Question 23

Thyroid gland is symmetrically enlarged with a firm and rubbery consistency. Biopsy obtained demonstrates well developed germinal centers. The likely pathology is:

Answer 23

Hashimoto’s thyroiditis

Question 24

Find needle aspiration of a thyroid mass is performed and demonstrates spindle shaped cells that express calcitonin. What is the most likely diagnosis?

Answer 24

Medullary thyroid cancer – arises from parafollicular cells of the thyroid gland which produce calcitonin

Question 25

Which of the following pathologic features is consistent with papillary thyroid cancer?
A. Anti-thyroglobulin antibodies
B. Foci of vascular invasion
C. Calcitonin expression
D. Empty appearing orphan Annie eye nuclei
E. Amyloid deposits

Answer 25

D. Empty appearing orphan Annie eye nuclei

Question 26

Which of the following is consistent with thyrotoxicosis?
A. Wide pulse pressure
B. Coarse skin
C. Constipation
D. Weight gain

Answer 26

A. Wide pulse pressure - due to increased systolic blood pressure via increased stroke volume + decreased diastolic blood pressure via decreased peripheral resistance

Question 27

How would an increase in thyroxine binding globulin affect serum levels of T4 and T3?

Answer 27

increased TBG may result in an increase in total T4 and T3 without an increase in hormone activity/without a change in free T4 or T3

Question 28

What is the effect of parathyroid hormone on phosphate?

Answer 28

PTH downregulates the expression of the sodium – phosphate sympoter in the proximal tubule. Therefore PTH enhances renal phosphate excretion.

Question 29

What is the effect of cortisol on skeletal muscle glucose utilization?

Answer 29

Causes decreased sensitivity to insulin – cortisol is powerful antagonist of insulin action at both adipose and muscle tissues, thereby decreasing glucose uptake and promoting elevated glucose levels in the blood.