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Flashcards in Thyroid Deck (82):
1

what does GH hypersecretion lead to in childhood?

gigantism

2

what does GH hypersecretion lead to in adults

acromegaly

3

what most often causes hypersecretory GH

pituitary adenoma

4

ACTH levels are ________ in adrenal insufficiency because of the primary adrenal disorder.

normal to high

5

ACTH is ___________ in adrenal insufficiency secondary to hypothalamic-pituitary hypofunction

low to absent

6

what metabolism does GH affect?

carbohydrate metabolism

7

How do deficiencies of GH manifest in children?

growth delays and fasting hypoglycemia

8

in adults how do growth hormone deficiencies manifest?

abdominal girth
reduce strength
decreased lean body mass

9

cut off point between micro and macro adenomas

<1 cm is microadenoma

10

An amino acid secreted episodically by pituitary lactotrophs

Prolactin

11

what do estrogens increase?

PRL secretion
gluccocorticoids

12

Is PRL needed to maintain lactation after nursing has begun?

No

13

PRL levels greater than what are highly suggestive of PRL-secreting adenomas

>200 ng/ml

14

what hormone is checked for growth hormone problems?

IGF-1

15

in men with a prolactinoma what will be suppressed?

testosterone

16

A glycoprotein hormone synthesized & secreted by pituitary thyrotroph cells .

Thyroid stimulating hormone (TSH)

17

Normal TSH level?

1.5-5.0

18

what do anterior pituitary deficiency result in?

leads to growth retardation, deficient or absent lactation, hypogonadism, hypothyroidism & adrenal insufficiency.

19

what are common causes of anterior pituitary deficiency

tumor, infarction, necrosis, infection, autoimmune inflammatory processes, certain Rx & genetic anomalies.

20

2 posterior pituitary hormones

oxytocin
ADH

21

Diagnostics of chronic for anterior pituitary deficiency

IGF-1; plasma testosterone, TSH, Free T4, and plasma cortisol response to synthetic ACTH

22

mot common functioning tumor

prolactinoma

23

Caused by pituitary adenoma causing excess GH or excess GHRH
Link to the MEN-I gene (Multiple Endocrine Neoplasia)

acromegaly

24

⇑ growth of jaw, hands, feet & internal organs
occurs if disease hits before closure of epiphyses

Gigantism

25

other random features of acromegaly

moist palms
CTS
deep, coarse voice
sleep apnea

26

most reliable lab study for possible acromegaly

IGF-1

27

most common presentation of prolactinoma

amenorrhea

28

Tx for acromegaly

endoscopic trans-sphenoidal surgery remains the treatment of choice
tx failure- sterotactic radiosurgery used in tx failures

29

is most galactorrhea due to prolatcinoma

no, only 40-45%

30

other txs besides surgery for acromegaly

dopamine agonists (bromocriptine, pergolide, cabergoline)
somatostatin
radidation

31

Short limbs & long narrow trunks, lg. head & mid-face hypoplasia & prominent brow
Intelligence is normal

achondroplastic dwarfism :)

32

complications of achondroplastic dwarfism

leg bowing
obesity
dental problems
frequent otitis media

33

Tx for prolactinoma

dopamine agonist- bromocriptine (qhs), cabergoline (2x weekly)

34

main side effect of dopamine agonists

naseau

35

signs of pituitary dwarfism

not apparent at birth
signs- micro-penis and hypoglycemia

36

gene mutation with achondroplastic dwarfs

mutations in FGFR3 gene

37

what does a lack of ADH cause

diabetes insipidus

38

diagnosis of diabetes insipidus

high serum osmolality >290
dilute and copious urine output
polydipsia
dehydration
hypernatremia

39

tx for SIADH

DDAVP (synthetic vasopressin) intranasally that causes a 50% or greater increase in urine osmolality is diagnostic for diabetes insipidus

40

signs of prolactinoma in men

low sex drive
low energy
hot flashes

41

lab workup for men w/ low sex drive

total and free testosterone
LH/ FSH
prolactin
TSH

42

what may nephrogenic diabetes insipidus respond to

HCTZ or in combo w/ indomethacin

43

Syndrome of high plasma ADH levels decreasing the serum osmolality
( <280mOsm/kg) , high urine osmolality

SIADH

44

what must you exclude before a dx of SIADH

Diagnosis must first exclude nephrotic syndrome, CHF, & cirrhosis by confirming thyroid, adrenal, renal & cardiac status.

45

what happens during a glucose tolerance test w/ acromegaly

growth hormone doesn't drop

46

The most common cause of ACTH-independent Cushing’s Disease

adrenal adenoma (<3 cm in diameter)

47

3 hormones released by adrenal

aldosterone
cortisol
epinephrine

48

what is cortisol involved in

stress hormone
sleep

49

what 3 hormones are involved in circadian rhythms

cortisol
growth hormone
adrenaline

50

common characteristics of cushings

truncal obesity, hypertension, striae, ecchymoses, proximal muscle weakness, hypokalemia, osteoporosis, and infertility.

51

what can cause false + labs for cushing's?

anti-seizure Rx
oral contraceptives
rifampin
spironolocatone

52

first test is suspecting cushings

24 urinary free cortisol

53

if you order a 24 urine what else do you need to order

creatinine to know it it was an adequate collection

54

2nd screening test for cushing's

2mg dexamethasone suppression test
if it hasn't suppressed that is abnormal

55

3rd screening test for cushing's

8 mg dexamethasone and then check if it is suppressed (points to adrenal source)

56

if suppression did occur with high dexamethasone test where do you suspect the tumor to be?

pituitary

57

other conditions that can create a hypercortisol state

Depression, Alcoholism, Anorexia Nervosa, Panic disorder, & Withdrawal syndromes (from drugs of abuse - narcotics & alcohol)

58

what is cosyntropin

synthetic ACTH

59

with primary adrenal insufficiency what hormone will be high?

ACTH and MSH
will have hyperpigmentation

60

present w/ HTH difficult to control
Persistent hypokalemia
Impaired glucose tolerance

hyperaldosteronism

61

workup of hyperaldosteronism

Aldosterone suppression test combined with increased NaCl (po or IV)
Spironolactone relieves - is diagnostic too
CT of adrenals (hyperplasia or carcinoma)

62

who are most affected by hyperaldosternism

women

63

most common cause of primary adrenal insufficiency worldwide

TB
autoimmune adrenalitis (industralized nations)

64

what conditions is prednisone use chronically and can lead to iatrogenic cushings

asthma
RA
IBD

65

what is myxedema

dough consistency due to high TSH (hypothyroidism)

66

other manifestations of myxedema

lethargy
thick tongue
slow mental functioning
coarse hair

67

diagnostics for panhypopituiarism

IGF-1 (low)
plasma testosterone (low)
TSH (normal-low)
Free T4 (low)
plasma cortisol response to synthetic ACTH

68

benign tumor but when removed could possibly affect pituitary

craniopharyngioma

69

what usually causes hyperaldosteronism

adenoma

70

screening test for hyperaldosteronism

normalize the K+
then plasma, renin serum aldosterone (want ratio, will be high)
24 hour urine (look for aldosterone)
CT scan of adrenal glands (no contrast)

71

test for hyperaldosteronism

saline suppression test
check aldosterone level before and after, confirmed if it doesn't suppress

72

what can cause hyperaldosteronism

bilateral adrenal hyperplasia or carcinoma

73

tx for hyperaldosteronism

spironolactone

74

what causes secondary hyperaldosteronism

from failure of pituitary secretion of ACTH
(women affected more)

75

main dx lab for addison's

Low 8AM plasma cortisol (< 5mg/dL) with elevated ACTH (> 200mg/dL)
high ACTH level
high plasma renin/low plasma aldosterone

76

test for pheochromocytoma

plasma free metanephrine and
24 hour urine catecholamines
confirm w/ CT or MRI

77

Tumor producing excess of catecholamines & their metabolites

pheochromocytoma

78

how do patients w/ a pheochromocytoma present

Nearly all affected pts have episodic hypertension while over 50% have sustained HTN with associated headache, sweating, & palpitations.

79

what are pheos associated w/?

Neurofibromatosis
Von Hippel-Lindau retinal angiomatosis
Cerebellar hemangioblastoma
Multiple endocrine neoplasia

80

treatment of choice for pheo

surgery

81

what must be done before surgery for a pheo

B/P controlled for1-2 weeks
use alpha-adrenergic blockers (sins) and beta blockers

82

Crisis tx for pheochromocytoma

regitine or nitroprusside to control BP