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Flashcards in endocrinology Deck (247):
1

high dose dex test-when does it suppress?

1. Suppresses ACTH/cortisol in a pituitary adenoma
2. Does NOT suppress is ACTH caused by ectopic ACTH (small cell carcinoma)

3. If adrenal secreting neoplasm, will have high cortisol, low ACTH and NO CHANGE with dexmethasone (ACTH already low and adrenal gland not responsive to it)

2

PTHrP

Squamous cell lung cancer
Breast cancer

3

branching papillae with a stalk and cuboidal epithelium. Ground glass appearance.
Psamomma bodies

papillary thyroid cancer

4

Sheets of Hurthle cells(eosinophilic cytoplasm) OR follicular cells

follicular thyroid cancer

5

large pleomorphic cells and multinucleated osteoclasts in thyroid histology. Also spindle cells

Anaplastic thyroid cancer

6

Uniform polygonal/spindle cells positive for calcitonin and amyloid

MTC

7

Carpal tunnel associated with:

hypothyroidism, diabetes

8

What is the single best test for hypothyroidism? Why?

TSH. Will be high. Because T4 levels can be within normal limits early on. TsH more sensitive. Serum t3 is the last thing to decline, a late indicator.

BUT if a hypothalamic problem, (central) then will not detect....

9

RANK-L is generated by

osteoblasts

10

Differentiation of osteoclasts is done by

RANK-ligand and monocyte CSF

11

OPG

secreted by osteoblasts, acts as a decoy receptor.

12

Bone turnover increased when:

Ratio of RANK-L:OPG is high.

13

How does PTH work on bone cells?

Stimulates secretion of Monocyte CSF and RANK-L BY osteoblasts to stimulate osteoclasts. Does not directly stimulate osteoclasts

14

How does low estrogen cause breakdown of bone?

Overexpression of RANK receptors causes more osteoclastic activity

15

Side effects of TZDs

Liver function--check LFTs.

Also, fluid retention

16

Signs of hypercalcemia

Stones
Groans (GI)
Bones
and psychiatric overtones (mental status)

17

rT3 made from

T4. Converted by hypothalamus and pituitary and also by peripheral tissues. If T4 is low, will have decreased rT3 too.

18

How does glucocorticoid affect the HPA axis?

Suppresses all levels, hypothalamus, pituitary, and adrenal. Can have adrenal crisis.

19

thyroid diverticulum arises from

floor of primitive pharynx

20

connects thyroid to tongue

thyroglossal duct

21

pyramidal lobe of thyroid=

persistence of thyroglossal duct

22

normal remnant of thyroglossal duct

formaen cecum

23

anterior midline neck mass that MOVES with swallowing

thyroglossal duct cyst

24

lateral neck mass that does not move with swallowing

branchial left cyst --from PERSISTENT CERVICAL SINUS

25

when does fetal adrenal become active

secretes cortisol late in gestation

26

fetal cortisol secretion controlled by

ACTH and CRH from fetal pituitary and placenta

27

Neuroblastoma

tumor of adrenal medulla in children

28

cells in adrenal medulla

chromaffin cells

29

left adrenal drains to

left renal vein-->IVC

30

right adrenal vein drains to

IVC

31

posterior pituitary derived from

neuroectoderm

32

anterior pituitary derived from

oral ectoderm (Rathke's pouch)

33

Melanotropin secreted by

anterior pituitary

34

acidophils

GH and prolactin

35

Basophils

B-FLAT
-FSH, LH, ACTH, TSH

36

alpha subunit of pituitary hormone

TSH, LH, FSH, hCG

37

B subunit of pituitary hormone determines

specificity

38

alpha cells of pancreas found where?

periphery

39

beta cells of pancreas found where?

inside

40

pathophys of insulin release

1. glucose enters
2. ATP increase
3. ATP gated K+ channels open
4. depolarization of beta cell
5. VG-Ca channel opens
6. insulin secretion

41

Does insulin cross the placenta?

No. Ok in pregnancy

42

which organs uptake glucose independently of insulin?

brain
RBC
intestine
Cornea
Kidney
Liver

43

GLUT 1 found in

RBC and brain (insulin independent)

44

GLUT 2 found in

beta cells, liver, kidney, small intestine

45

GLUT 4

adipose tissue, skeletal muscle

46

effect on insulin on kidneys

increased NA retention

47

Things that increase insulin

hyperglycemia
GH
B2 adrenergic ANTAGONIST

48

Things that decrease insulin

hypoglycemia
somatostatin
a-2 agonist

49

What type of receptor is insulin receptor?

tyrosine kinase

50

pathophys after insulin binds cell

Tyrosine kinase phosphorylates
--IP3 causes GLUT-4 vesicles to fuse and glycogen, lipid, and protein synthesis
--RAS/MAP kinase causes cell growth

51

Can RBCs use ketones for energy/

NO! they have no mitochondria

52

effects of glucagon

Glycogenolysis
gluconeogenesis
lipolysis
ketone

53

Glucagon inhibited by

somatostatin
and obvi insulin and hyperglycemia

54

TRH stimulates

TSH and prolactin

55

Dopamine inhibits

prolactin

56

CRH stimulates

ACTH
MSH (melanocyte stimulating hormone)
beta endorphin

57

Somatostatin inhibits

GH
TSH

58

which drugs would stimulate prolactin secretion?

Antipsychotics (dopamine antagonist)
Also OCPs

59

prolactin negative feedback at

hypothalamus--increasees dopamine

60

what stimulates prolactin secretion

TRH

61

Describe how growth hormone works

GH stimulates liver to release IGF-1/somatomedin. Causese growth

62

when is secretion of GH high?

exercise and sleep (when glucose is low). Pulsatile secretion.

63

Gh inhibited by

glucose and somatostatin

64

bilateral adrenal hyperplasia

congential adrenal hyperplasia

65

Boy with ambiguous genitalia
-->hypertension, hypokalemia

17a-OH deficiency ("boys are 17 when they hit puberty")
high aldo
low testosterone

66

Girl with normal sex organs
--hypertension, hypokalemia

17alpha-OH deficiency

67

Girl with ambigulous genitalia
--hypotension, hyperkalemia
--High renin

21 OH deficiency

68

Boy with hypotension, hyperkalemia, and increased renin

21 OH deficiency

69

Girl with ambiguous genitalia
--Hypertension

11B OH deficiency ("girls are 11 when they hit puberty")
--will have high 11 deoxycorticosterone

70

Boy with normal genitalia
--hypertension

11B OH deficiency

71

Cortisol effects
BBIIG

blood pressure
decreased bone formation
Inflammatory (anti)
Insulin resistance
Gluconeogenesis

72

how does cortisol maintain blood pressure?

upregulates alpha 1 receptors on arterioles

73

how does cortisol effect anti-inflammatory response?

1. inhibit leukotriene and prostaglandin synthesis
2. inhibit leukocyte adhesion
3. block histamine release
4. reduce eosinophil count
5. block IL-2 production

74

PTH secreted by what cells

chief cells

75

effects of PTH

1. increased bone resorption Ca and Po4
2. Increased calcium resabsorption
3. Decreased phosphate in PCT
4. Stimulates kidney 1alpha-OH

76

Overall effect of PTH on serum levels

Ca increase
PO4 decrease
urine phosphate increase
PTH=Phosphate trashing hormone

77

What increases PTH secretion

decreased calcium
slight decrease Mg2+

78

What decreases PTH secretion

HUGE decrease in Mg2+

79

Cause of MG2+ deficiency

diarrhea
Aminoglycosides
diuretics
alcohol

80

Effect of vitamin D?

Increases calcium reabsorption in GUT
Increases phosphate release from matrix
Increases intestinal phosphate reabsorption
-->Thus, INCREASES CALCIUM AND PO4

81

Vitamin D3 from

sun exposure

82

Vitamin D2 from

plants

83

what increases 1, 25 OH2 production

Increased PTh
decreased PO4
decreased ca

84

what cells make calcitonin

parafollicular cells

85

effect of calcitoning

decreases bone resorption

86

t3/T4 receptor

steroid

87

IGF-1, PDGF, EGF (growth factor) receptor

Intrinsic tyrosine kinase-->MAP kinase

88

acidophile and cytokine recptor

receptor tyrosine kinase

89

Nitric oxide, ANP receptor

cGMP

90

vitamin D receptor

steroid

91

GnRH, GHRH signaling pathway

IP3

92

Oxytonin and ADH signaling pathway

IP3

93

TRH signaling pathway

IP3

94

FSH, LH, ACTH, TSH, pathway

cAMP

95

hitamine and gastrin pathway

IP3

96

PTH and calcitonin signaling pathway

cAMP

97

glucagon signaling pathway

cAMP

98

SHBG and testosterone

Increase SHBG lowers testosterone.

99

SHBG levels during pregnancy

Increase.

100

Excess iodide temporarily inhibits thyroid peroxidase

Wolff Chaikoff effect

101

what converts t4 to t3

5' deiodinase

102

thyroid binding globulin effect

binds hormone, preventing it from having any effects

103

When are TBG levels low? high?

low: hepatic failure
high: pregnancy

104

how does thyroid hormone increase basal metabolic rate?

Upregulates Na/K ATPase

105

peroxidase

coupling of MIT and DIT
--oxidation of iodide

106

Methimazole effect

Inhibits peroxidase only
'A MONO EFFECT)

107

propylthiouracil effect

Inhibits peroxidase AND peripheral 5'deiodinase
A POLY effect

108

Cushing's disease

INCREASED ACTH causing cushing's syndrome

109

Other causes of cushing's syndrome

ectopic ACTH
Adrenal hyperplasia/adenoma

110

striae

hypercortisolism

111

low dose dex: cortisol elevated
high dose dex: cortisol suppressed

cushing's disease
-ACTH producing tumor

112

low dose dex: coritsol elevated
high dose dex: cortisol elevated

Ectopic ACTH OR adrenal hyperplasia/adenoma/carcinoma

113

Conn's syndrome

aldosterone secreting adenoma

114

Treatment for Conn's or adrenal hyperplasia

surgery or spironolactone

115

Cause of secondary hyperaldosteronism

renal artery stenosis
CHF
nephrotic syndrome (perception of low intravascular volume)

116

Cause of addison's

Adrenal Atrophy
Absence of hormone

117

hypotension
hyperkalemia
acidosis

signs of adrenal insufficiency

118

how to disginguish primary from secondary adrenal insufficiency

Primary
--High ACTH: skin pigmentation
--hyperkalemia (ALSO aldosterone is low!)

Secondary:
--No hyperkalemia
--ONLY cortisol is low
--LOW ACTH

119

how to distinguish primary from secondary hyperaldosteronism?

renin levels

120

Pheos associated with:

NF-1
MEN2A
MEN2B

121

Treatment for pheo

1. alpha blockade
2. beta blockade
3. surgery

122

Rule of 10's

Pheos are 10%:
-malignant
-bilateral
-extra-adrenal
-calcify
-kids

123

describe pathway of phenylalanine breakdown

phenylalanine
tyrosine
L-dopa
Dopamine
norepinephrine
epinephrine

124

Breakdown product of dopamine

HVA, increased in pheos along with VMAs

125

Waterhouse friederichsen

acute primary adrenal insufficiency from adrenal hemorrhage

126

Waterhouse friederichsen is associated with

neisseria meningitidis
DIC/Shock

127

dx: neuroblastoma

elevated homovanillic acid in the urine.

128

What's different about neuroblastoma vs a pheo?

Less likely to develop hypertension

129

oncogene associated with neuroblastoma

n-myc

130

how does a neuroblastoma classically present?

1. abdominal fullness
2. compression of sympathetic chain (horner's)
3. small blue round cells

131

facial/perorbital myxedema

sign of hypothyroidism

132

pretibial myxedema
exopthalmos

Specific to graves. Not found in other causes of hyperthyroidism

133

dx: hypothyroidism

increased TSH (if primary)
Decreased T4

134

dx: hyperthyroidism

decreased TSH (if primary)
increased free or total T4/T3

135

What is the most sensitive test for primary hypothyroidism?

increased TSH

136

hashimotos association

HLA-DR5

137

Histology of hashimoto's

Hurthle cells
lymphocytic infiltrate with germinal centers

138

enlarged nontender thyroid

hashimoto's

139

pathophys of hashimotos'

anti-thyroglobulin antibodies

140

cretinism caused by

severe fetal hypothyroidism

141

Cause of endemic cretinism

lack of dietary iodine

142

cause of sporadic cretinism

Defect in T4 formation

143

Pot bellied, pale, puffy faced kid with
Protruding umbilicus and Protuberant tongue

5P's of hypocretinism

144

self-limited hypothyroidism after a flu like illness

subacute thyroiditis

145

Histology of subacute thyroiditis

granulomatous inflammation

146

hypothyroidism with increased ESR, jaw pain, early inflammation, and a tender thyroid

subacute thyroiditis

147

hypothyroidism where thyroid is replaced by fibrous tissue

riedel's thyroiditis

148

fixed, hard rock like and painless goiter

riedel's

149

Cause of Riedel's thyroiditis

IgG4 systemic disease
--overproduction of IgG4, causing fibrosis

150

Jod basedow phenomenon

thyrotoxicosis if a patient with iodine deficiency goiter is made iodine replete

151

Toxic multinodular goiter etiology

mutation in TSH receptor

152

pathophys thyroid storm

stress causes a huge catecholamine surge and arrhythmia

153

serious complication of hyperthyroidism

thyroid storm.

154

ALP during thyroid storm

Increased

155

Hashimoto's thyroiditis cancer

lymphoma

156

orphan annie's eyes, psamomma bodies, nuclear grooves. Excellent prognosis

papillary carcinoma

157

Calcitonin producing tumor with sheet of cells

medullary carcinoma

158

who gets anaplastic thyroid cnacer

older pts, poor prognosis

159

cystic bone spaces filled with brown fibrous tissue

osteitis fibrosa cystica

160

Cause of osteitis fibrosa cystica

High PTH

161

cause of primary hyper PTH

adenoma

162

lab findings in primary hyperPTH

hypercalcemia
hypercalciuria
hypophosphatemia
increased alkaline phosphatase

163

cause of secondary hyperparathyroidism

chronic renal disease

164

Labs in secondary hyperparathyroidism

hypOcalcemia
hypophosphatemia
increased alkaline phosphatase

165

renal osteodystrophy

bone lesions from 2ndary or tertiary hyperparathyroidism

166

Tertiary hyperparathyroidism

Autonomous hyperparathyroidism secretion from chronic renal disease.
-VERY high PTH
-hyPERcalcemia

167

Causes of hypoPTH

1. DiGeorge
2. Surgical excision accidnetal
3. autoimmune destruction

168

Findings of Hypoparathyroidism

hypocalcemia
tetany
Chvostek's sign
Trousseau's sign

169

Chvostek's sign

tapping of facial nerve=contraction of facial muscles

170

Trousseau's sign

Occlusion of brachial artery with BP cuff

171

Pseudohypoparathyroidism

Kidney unresponsive to PTH.
--inherited.
--hypocalcemia with shortened 4th/5th digits and short stature

172

Inheritance of pseudohypoparathyroidism

autosomal dominant

173

Dx of acromegaly

Increased serum IGF-1
OR
Glucose tolerance test-->failure to suppress serum GH
OR
MRI for pituitary mass

174

Treatment for prolactinoma

bromocriptine
cabergoline
--dopamine agonists

175

treatment of acromegaly

Pituitary adenoma resection
somatostatin analog

176

causes of central DI

tumor
trauma/surgery
histiocytosis X

177

causes of nephrogenic DI

lithium
hypercalcemia
demeclocycline

178

lab findings of diabetes insipidus

Urine specific gravity < 1
serum osmolality > 290

179

dx of diabetes insipidus

water deprivation test

180

how to distinguish central vs nephrogenic DI

Central: Will respond to Desmopressin
Nephrogenic: No response

181

Treatment for nephrogenic diabetes insipidus

hydrochlorothiazide
indomethacin
amiloride

182

Main problem in SIADH

hyponatremia from:
1. High ADH
2. Low aldosterone

183

treatment of SIADH

1. fluid restriction
conivaptan
demeclocycline

184

drugs that can cause SIADH

cyclophosphamide
pulmonary dz too

185

Causes of hypopituitarism

1. Pituitary adenoma/craniopharyngioma
2. Sheehan
3. empty sella
radiation and brain injury

186

Cause of coma in type 2 diabetes

hyperosmolarity of blood

187

cause of dehydration in insulin deficiency

osmotic diuresis with glucose and ketones in the urine

188

Main BUZZWORD FOR DIABETES

nonenzymatic glycosylation

189

nonenzymatic glycosylation is responsible for

small vessel disease and large vessel disease
--retinopathy, glaucoma, renal failure, nephropathy
-CAD

190

Ostmotic damage in diabetes causes

neuropathy and cataracts

191

Histology of T1D

islet leukocytic infiltrate

192

Histology of T2D

islet amyloid deposit

193

Serum labs in diabetic ketoacidosis

Hyperkalemia (but depleted intracellular K)
Acidosis
Decreased bicarb
(anion gap metabolic acidosis)

194

signs of carcinoid syndrome (labs)

Increased 5-HIAA
Niacin deficiency

195

treatment of carcinoid syndrome

octreotide (somatostatin analog)

196

Rule of 1/3rds

applies to carcinoid syndrome
--1/3 metastasize
--1/3 present with a second malignancy
--1/3 have multiple tumors

197

zollinger ellison associated with

MEN type I

198

Men 1 tumor

Pituitary, Pancreas, parathyroid (3P's)

199

Men 2A

Parathyroids and pheo(2P)

200

Men 2B

Pheo (1P)

201

MEN inheritance

autosomal dominant

202

gene mutation in MEN 2A and 2B

ret

203

pt with kidney stones and stomach ulcers

Men1
--Hyperparathyroidism
--Zollinger ellison (pancreas)

204

Medullary thyroid cancer seen in

MEN2

205

Oral ganglioneuromatosis

Men2B
--Associated with marfanoid habitus

206

intermediate insulin

NPH

207

Effects of metformin

decreased gluconeogenesis
Increased glycolysis
Increased peripheral glucose uptake

208

Most serious adverse effect of metformin

1. lactic acidosis

209

Who is metformin contraindicated in?

renal failure

210

can you use metformin in type 1?

YES--does not require islet function to work! It enhances glucose uptake without insulin

211

Mechanism of sulfonylureas

Increases insulin release

212

tox: sulfonylureas

first generation: disulfiram
2nd generation: hypoglycemia

213

Tobultamide
chlorpropamide

first generation sulfonylurea

214

glyburide
glimepiride
glipizide

second generation sulfonylureas

215

pioglitazone
rosiglitazone

TZDs

216

mechanism of TZDs

increase insulin sensitivity in peripheral tissue
--Binds PPAR-y nuclear transcription factor

217

Indication of TZDs

Type 2 diabetes

218

Side effect of TZD

weight gain, edema
hepatotoxicity
heart failure

219

acarbose
miglitol

alpha glucosidase inhibitors

220

mech: alpha glucosidase inhibitor acarbose miglitol

Inhibit intestinal brush border a-glucosidases
--decreased sugar absorption
--reuces postprandial hyperglycemia

221

tox: a-glucosidase inhibitors

GI disturbances

222

pramlintide

amylin analog

223

mechanism pramlintide

decreases glucagon

224

Mechanism: exenatide/liraglutide

increase insulin
decrease glucagon

225

linagliptin
saxagliptin
sitagliptin

DPP-4 inhibitors

226

-gliptin mechanism

Increase insulin
decrease glucagon

227

Which oral anti-diabetic agents can be used in type 1?

metformin
pramlintide

228

side effect of acarbose/miglitol

GI disturbance

229

Side effect of GLP-1

GLP-1

230

Side effect of DPP4 gliptins

urinary/respiratory infections

231

Side effects of propylthiouracil/methimazole

agranulocytosis
aplastic anemia
skin rash

232

side effect of propylthiouracil

hepatotoxicity

233

side effect of methimazole

teratogen

234

demecoglycline use

SIADH

235

octreotide use

Somatostatin analog

acromegaly
carcinoid (somatostatin inhibits gastric neuroendocrine cells, gastrin, CCK,
gastrinoma
glucaonoma
esophageal varices

236

oxytocin use

stimulates labor
milk let down
uterine hemorrhage (contracts spiral arteries?)

237

tox of demeclocycline

nephrogenic DI (if too much)
photosensitivity
bone/teeth abnormalities

238

Mechanism glucocorticoids

Inhibits phospholipase A2 and Cox2
--decreases leukotrienes and prostaglandins

239

How do you treat addison's disease

Give glucocorticoids

240

What happens if you stop giving glucocorticoids suddenly?

Can have adrenal insufficiency (takes time for adrenal to take over, HPA has been suppressed for such a long time)

241

Side effect of glucocorticoids

peptic ulcers
diabetes

242

origin of thyroid parafollicular cells

neural crest cells

243

classic addison's presentation

Hyperpigmentation!
Less insulin requirement if diabetic
Orthostatic hypotension
GI symptoms
Fatigue, weight loss
--TYPICALLY LOSS OF CORTISOL AND ALDOSTERONE

244

Leuprolide mechanism

GnRH agonist:
--Increase testo/DHT
--then DECREASE
a form of androgen deprivation therapy
--abolishes pulsatile secretion

245

Finasteride

5a-reductase
--increase in testosterone
--decrease in DHT

246

flushing
diarrhea
bronchospasm

carcinoid syndrome

247

Sarcoidosis results in hypercalcemia from

Excess vitamin D (calcitriol)