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Flashcards in Endocrinology Deck (142)
1

What receptors on what cells lead to NO release when stimulated?

Muscarinic receptors on endothelial cells

2

Most pituitary hormones act via cAMP-linked receptors. Which ones dont and how do they work?

GnRH, Oxytocin, and ADH act via IP3 system. Prolactin and GH act via JAK/STAT tyrosine kinases

3

Steroid hormones bind their receptors in the cytoplasm and translocate to the nucleus. What is the exception to this?

Thyroid hormones bind their receptor in the nucleus

4

What inhibits uptake and organification of iodide?

Anions (perchlorate, pertechnetate) inhibit uptake and excess iodine (Wolff-Chaikoff effect) inhibits organification

5

Why are beta blockers helpful in hyperthyroidism?

Combat sympathetic effects (except increased o2 demand and weight loss) and they decrease peripheral T4 to T3 conversion

6

Give the change in cortisol levels in the following conditions during a dexamethasone test (give low dose first then high dose): normal, ACTH-pituitary tumor, ectopic ACTH-producing tumor, cortisol-producing tumor

Normal - up (high dose not done). ACTH-pituitary tumor - up down. Ectopic ACTH-producing tumor - up up. Cortisol producing tumor - up up.

7

Conns syndrome

Primary hyperaldosteronism

8

Causes of waterhouse-friederichsen syndrome

Neisseria meningitidis septicemia, DIC, endotoxic shock

9

Test of choice to diagnose pheochromocytoma

Urinary VMA or metanephrines

10

Treatment for pheochromocytoma

Alpha antagonists (esp phenoxybenzamine) and surgery

11

Most common extracranial neoplasm in children

Neuroblastoma

12

Non-rhythmic eye movements with myoclonus (opsoclonus-myoclonus) in child

Neuroblastoma

13

Test of choice for neuroblastoma

HVA (breakdown product of dopamine)

14

What genetic change is associated with neuroblastoma

N-myc overexpression signals rapid tumor progression

15

Spinal cord compression, pancytopenia, hepatomegaly, palpable nodules, proptosis, truncal ataxia

Neuroblastoma

16

Hypotension, tachycardia, hypoglycemia, with existing history of vomiting abdominal pain and weight loss

Acute adrenal crisis (will occur in patients with adrenal insufficiency during stress)

17

Increased risk of what cancer in hashimotos thyroiditis

Non-hodgkin lymphoma

18

Histology of Hashimotos thyroiditis

Lymphocytic infiltrate with germinal centers with Hurthle cells. Thyroid will be moderately enlarged and nontender

19

Cretinism

Defect in T4 formation or developmental failure in thyroid formation

20

Pot-bellied, pale, puffy-faced child with protruding umbilicus and protuberant tongue

Cretinism

21

Self-limited hypothyroidism following flulike illness

Subacute (de Quervain) thyroiditis. Will see granulomatous inflammtion, jaw pain, tender thyroid

22

Riedels thyroiditis

Thyroid replaced by fibrous tissue (hypothyroid). Will find fixed, hard painless goiter

23

What do you have to rule out if you suspect Riedels thyroiditis?

Iodine deficiency, thyroglossal duct cyst, goitrogens, Wolff-Chaikoff effect

24

Treatment for Graves

Glucocorticoids to reduce inflammation

25

What is another name for De Quervains Thyroiditis?

Granulomatous thyroiditis. (also subacute thyroiditis)

26

Give the histology of each of the following thyroid cancers: papillary, follicular, medullary

Papillary - ground glass nuclei, psammoma bodies, nuclear grooves. Follicular - uniform follicles. Medullary - sheets of cells in amyloid stroma

27

What type of bone changes do you see in hyperparathyroidism?

Subperiosteal reabsorption with cystic degeneration

28

What is osteitis fibrosa cystica associated with?

Primary hyperparathyroidism

29

What GI abnormality is primary hyperparathyroidism associated with?

Constipation

30

What is required to diagnose complete central DI?

An increase of 50 percent or greater in urine osmolality on DDAVP administration

31

Lab findings in prolactinoma

Decreased GnRH, decreased LH, decreased testosterone

32

One difference in symptoms between pheochromocytoma and neuroblastoma

Pheochromocytoma causes episodic hypertension

33

To where do the left and right adrenal veins respectively drain?

Left - left renal. Right - IVC

34

What do neurophysins do and what does their deficiency cause?

Carry ADH and oxytocin from hypothalamus to posterior pituitary. Deficiency leads to central DI

35

What are the posterior and anterior pituitary respectively derived from?

Posterior (neurohypophysis) - Neuroectoderm, Anterior (adenohypophysis) - Oral ectoderm (Rathkes pouch)

36

What do the acidophils and basophils of the pituitary gland make?

Acidophils - GH, prolactin. Basophils - FSH, LH, ACTH, TSH

37

What organs dont need insulin for glucose uptake?

Brain, RBCs, Intestine, Cornea, Kidney, Liver

38

What type of transport do GLUT transporters carry out, and what is their specificity for?

Facilitated diffuse for D-glucose

39

What type of receptor is the insulin receptor?

RTK

40

What protein gets activated as a result of insulin receptor stimulation in hepatocytes?

Protein phosphatase (which phosphorylates glycogen synthase)

41

Which glucose transporter is insulin dependent?

GLUT-4

42

Give the pituitary hormones secreted or inhibited by each of the following hypothalamic secretions: TRH, Dopamine, Somatostatin, Prolactin

TRH - stim TSH and prolactin. Dopamine - inhibits prolactin. Somatostatin - inhibits GH and TSH. Prolactin - Inhibits GnRH

43

What substance acts counter to ACTH in synthesis of adrenal hormones?

Ketoconazole (inhibits cholesterol to pregenolone conversion by desmolase, which is stimulated by ACTH)

44

Metyrapol

Inhibits cortisol formation by 11B-hydroxylase. Leads to decreased cortisol and increased ACTH (reflexively)

45

Relative levels of mineralocorticoids, cortisol, and sex hormones in 17a-hydroxylase deficiency

MC - high, cortisol - low, sex hormones - low

46

Relative levels of mineralocorticoids, cortisol, and sex hormones in 21-hydroxylase deficiency

MC - low, cortisol - low, sex hormones - high

47

Relative levels of mineralocorticoids, cortisol, and sex hormones in 11b-hydroxylase deficiency

MC - Aldosterone low but 11-deoxycorticosterone high, cortisol - low, sex hormones - high

48

Hypertension, hypokalemia, male pseudohermaphroditism if XY or female with lacking secondary sex characteristics if XX

17a-hydroxylase deficiency

49

Hypotension, hyperkalemia, increased renin, volume depletion, masculinization, female pseudohermaphroditism

21-hydroxylase deficiency

50

Hypertension, masculinization

11b-hydroxylase deficiency. Contrast with 21-hydroxylase deficiency, which is masculinization with HYPOtension

51

What is the most common congenital adrenal hyperplasia?

21-hydroxylase deficiency

52

What does prolonged ACTH stimulation do to the adrenal gland histologically?

Causes hyperplasia of the fasiculata

53

Treatment of congenital adrenal hyperplasias

Suppress ACTH with exogenous corticosteroids

54

What effect does GH have on IGF-1 production?

Stimulates IGF-1 production in liver (no effect on hypothalamic activity)

55

Amenorrhea, galactorrhea, low libido, infertility

Prolactinoma (pituitary adenoma)

56

What secondary effect can a prolactinoma have in women?

Hypogonadism which leads to osteoporosis (prolactin inhibits GnRH release)

57

Medical treatment for prolactinomas

Bromocriptine or cabergoline (dopamine agonists)

58

Medical treatment for acromegaly

Octreotide

59

What factors cause increased GH release

Stress, exercise, and hypoglycemia

60

Serum sodium in DI

Greater than 142

61

Water deprivation test results in DI

Urine osmolality fails to increase (stays less than 300-500)

62

Treatment for DI

Central - desmopressin. Nephrogenic - HCTZ, indomethacin, or amilioride

63

Typically where is the dysfunction in central DI?

Hypothalamus. Usually posterior pituitary problems only cause transient DI

64

Treatment for SIADH

Demeclocycline or water restriction

65

Causes of SIADH (4)

Ectopic ADH (small cell), 2) CNS disorders/head trauma, 3) Pulmonary disease, 4) Drugs (eg cyclophosphamide)

66

Complication of pituitary adenoma

Pituitary apoplexy (bleeding into existing pituitary adenoma)

67

What type of insulin is the preferred treatment for DKA?

Regular (not short acting)

68

What factors tend to increase or decrease blood glucose in type 1 diabetics?

Infection, pain, and sleep deprivation tend to increase blood glucose. Exercise decreases blood glucose

69

What compounds are central in the pathogenesis of T2DM?

FFAs and serum TGs

70

What are the tests of choice for T1DM, T2DM, and gestational diabetes respectively?

T1 and T2 DM - fasting blood sugar (in the US). Gestational - OGTT

71

What are potassium levels like in DKA?

Hyperkalemia is present, but intracellular levels of K are very low due to transcellular shift from decreased insulin

72

What is your first step in management if you suspect mucormycosis in a DKA patient?

Biopsy and look at it under the microscope

73

Pathogenesis of fetal macrosomia in gestational diabetes

Maternal glucose crosses placenta, hyperplasia of fetal islets, fetal hyperinsulinemia followed by fetal hypoglycemia, fetal macrosomia

74

Rule of thirds for carcinoid

One third metastasize, One third present with second malignancy, one third present as multiple

75

Treatment for carcinoid syndrome

Octreotide

76

Test of choice for Zollinger-Ellison

Infusion of secretin (will see increased gastrin secretion in Z-E syndrome)

77

MEN 1

Pituitary (prolactin or GH), Parathyroid, Pancreas (ZES, insulinoma, VIPoma, glucagonoma). Kidney stones and stomach ulcers. Draw a diamond

78

MEN 2A

Medullary thyroid carcinoma (calcitonin), Pheochromocytoma, Parathyroid tumors. Draw a square

79

MEN 2B

Medullary thyroid carcinoma (calcitonin), pheochromocytoma, oral/intestinal ganglioneuromatosis (neuromas). Marfinoid habitus. Draw a triangle.

80

How does pheochromocytoma often present

Headache

81

Genetic mutation associated with MEN 2A and 2B

Ret mutation

82

List the insulins and include their duration of action

Rapid - lispro and aspart. Short acting - insulin. Intermediate - NPH. Long-acting - Glargine and detemir

83

Treatment for gestational diabetes

Insulin

84

Tolbutamide

Sulfonylurea (first generation)

85

Chlorpropamide

Sulfonylurea (first generation)

86

Glyburide

Sulfonylurea (second generation)

87

Glimepiride

Sulfonylurea (second generation)

88

Glipizide

Sulfonylurea (second generation)

89

Metformin

Biguanide

90

Pioglitazone

Glitazone (aka thiazolidinedione)

91

Rosiglitazone

Glitazone (aka thiazolidinedione)

92

Acarbose

Alpha-glucosidase inhibitor

93

Miglitol

Alpha-glucosidase inhibitor

94

Pramlinitide

Mimetic (diabetes drug)

95

Exenatide

GLP-1 Analog

96

Sulfonylurea mechanism

Closes K channel in beta cell membrane, triggering insulin release via increased Ca influx

97

Mechanism of biguanides (metformin)

Unknown. Decreased gluconeogenesis, increased glycolysis, increased peripheral insulin sensitivity

98

Mechanism of Glitazones/Thiazolidinediones

Increased insulin sensitivity via PPAR-gamma binding

99

Alpha-glucosidase inhibitor mechanism

Inhibits intestinal brush border alpha-glucosidases leading to decreased glucose absorption

100

Mimetics (pramlinitide) action

Amylin analogue. Leads to decreased glucagon secretion and delayed gastric emptying and promotes satiety

101

Exenatide (GLP-1 analog) effects

Increased insulin, decreased glucagon release

102

What does activation of PPAR-gamma do and what drugs activate it?

Increases insulin sensitivity and levels of adiponectin. Glitazones/thiazolidinediones

103

Contraindications of metformin

Renal failure (can cause lactic acidosis)

104

Toxicities of glitazones/thiazolidinediones

Weight gain, edema, hepatotoxicity, heart failure

105

PTU and methimazole

Block peroxidase and inhibit iodide organification. PTU also blocks 5-deiodinase (decreasing peripheral conversion of T4 to T3).

106

Toxicities of PTU and methimazole

Rash, agranulocytosis, aplastic anemia, hepatotoxicity (PTU), teratogen (methimazole)

107

Necrolytic migratory erythema, elevated erethematous rash on groin, hyperglycemia, stomatitis, cheilosis, abdominal pain, anemia

Glucagonoma

108

Uses of GH

GH deficiency and Turner syndrome

109

Uses of octreotide

Acromegaly, carcinoid, gastrinoma, glucagonoma, hepatorenal syndrome

110

Uses of oxytocin

Stimulate labor, uterine contractions, milk let down, and controlling uterine hemorrhage

111

Demeclocycline

ADH anatgonist, use in SIADH. May cause nephrogenic DI, photosensitivity, abnormalities of bone and teeth

112

What effect do glucocorticoids have on liver sugar metabolism?

Stimulate gluconeogenesis (have an anti-insulin effect)

113

Uses of glucocorticoids

Addisons, inflammation, immune suppression, asthma, Graves

114

What is the bone finding in Cushings?

Osteoporosis

115

3 tumors secreting stuff you cannot suppress

Parathyroid adenoma making PTH, adrenal adenoma making cortisol, adrenal tumor secreting aldosterone

116

Most common cause of hypopituitarism in adults

Nonfunctioning pituitary adenoma

117

What type of necrosis occurs in Sheehans syndrome?

Coagulative (pituitary is not part of the brain)

118

Second most common cause of hypopituitarism in adults

Sheehans syndrome

119

Most common cause of hypopituitarism in kids

Craniopharyngioma

120

First signs of hypopituitarism

Amenorrhea or impotence (due to loss of gonadotropins)

121

Test of choice for pituitary dwarfism

Sleep GH and IGF-1 levels

122

What amino acids stimulate growth hormone release?

Histidine and arginine

123

Order in which hormone production disappears in hypopituitarism

(first to go) Gonadotropins, GH, TSH, ACTH, prolactin (last to go)

124

Stimulators of prolactin synthesis

OCPs, hydralazine, Ca channel blockers, psychotropic drugs, primary hypothyroidism

125

What non-thyroid related symptom is seen in women with primary hypothyroidism and why?

Galactorrhea. Low thyroid hormones levels increase synthesis of TSH and TRH. TRH stimulates prolactin synthesis

126

Prolactin level above what value always means prolactinoma?

200

127

Increased T4 with a normal TSH

Estrogens such as OCPs or pregnancy (due to increase in TBG)

128

Use of I-131 test

Distinguishes Graves from exogenous thyroid supplementation

129

Cardiac abnormality associated with Graves

A-fib

130

Most common symptom of hypothyroidism

Proximal muscle weakness (cannot get out of chairs, serum CK will be high)

131

Give the rule for cold thyroid nodules

Any cold nodule in a man or child is cancer until proven otherwise. Cold nodules in (esp older) women are often benign

132

Thyroid cancer prognosis

(Best) Papillary then follicular then medullary (worst)

133

Most common cause of hypocalcemia

Hypoalbuminemia (albumin carries about 40 percent of total Ca)

134

Why is alkalosis associated with tetany?

Because albumin is made of acidic AAs, and thus will bind more free calcium (lowering ionized calcium levels) in alkalotic state. Will not have hypocalcemia on labs but will have tetany and functional hypocalcemia

135

Purple striae, obesity, thin extremities

Cushings

136

What type of Cushings can you suppress with high dose dexamethasone?

Pituitary

137

What will the low dose dexamethasone suppression test result be in all types of Cushings?

Failure to suppress. You will, however, see suppression at low doses in normal patients

138

Why do Cushings patients have thin exremities and central obesity?

Cortisol encourages protein (muscle) breakdown, but leads to hyperglycemia, which leads to insulin release, which causes fat and sugar storage centrally. Essentially we are moving tissue from our muscles centrally

139

Why are the striae in Cushings purple?

Cortisol decreases collagen synthesis

140

Why will patients with Conns syndrome have tetany?

Metabolic alkalosis causes functional hypocalcemia

141

Patient with neurofibromatosis and HTN

Suspect pheochromocytoma. Check VMA and metanephrines

142

Only meningitis with petechial lesions

N meningitidis