Pituitary Dysfunction Flashcards Preview

Digestive, Endocrine, and Metabolic Systems > Pituitary Dysfunction > Flashcards

Flashcards in Pituitary Dysfunction Deck (36):
1

What stimulates the release of growth hormone?

Sleep
Puberty
Glucagon
Hypoglycemia
Stress
High levels of amino acids
Alpha-adrenergic agonists

2

What suppresses the release of growth hormone?

Aging
Somatostatin
Hyperglycemia
Free fatty acids

3

Disorders in the HPA axis can be either central or peripheral. What does this mean?

Central disorders arise from problems in the hypothalamus or pituitary, while peripheral disorders arise from the target organ.

4

Describe the process of dynamic pituitary testing.

You use the natural stimulus for a hormone to induce secretion. If the natural stimulus does not elicit the expected response, then you know that hormone is somehow affected.

5

What organ secretes IGF-1?

The liver (in response to GH)

6

What is the best screening test for acromegaly?

IGF-1 levels

7

What three categories of treatment can help treat acromegaly?

- Surgical excision of the GH-secreting tumor
- Radiation therapy of the GH-secreting tumor
- Somatostatin analogues or GH antagonists

8

What happens to GH over the lifespan?

Its levels decrease by about 14% per decade.

9

Use of GH in those with adult-onset growth hormone deficiency has ________________.

not been shown to decrease fracture risk or improve longevity

10

_______________ tests can be used to test for GH reserves, but it is not done often because of its intrinsic danger.

Insulin-induced hypoglycemia

11

_______________ are more common in women and present with infertility and menstrual irregularities.

Prolactinomas

12

_______________ is used in all those with prolactinomas, except for in pregnant women who receive bromocriptine because of its favorable pregnancy safety profile.

Cabergoline

13

What can cause low prolactin levels?

Use of dopamine agonists or infiltrative neoplasms

14

Cushing's disease can be either ____________ or _____________.

ATCH-dependent (75% of cases) or ACTH-independent (25%)

15

The nadir of cortisol usually occurs at _________, while the peak occurs at __________.

~midnight; ~8:00 AM

16

When should you test someone's cortisol to test for Cushing's syndrome?

Midnight (you have them chew a cotton ball and send it in)

17

What can cause adrenal insufficiency?

- Opioids
- Surgical removal of the pituitary
- Use of exogenous steroids (that then suppress the HPA axis)

18

When should you test cortisol levels for suspicion of adrenal insufficiency?

~8:00 AM

19

Most _____________ adenomas are silent because their secreted product is dysfunctional.

gonadotrope

20

What is apoplexy?

Sudden hemorrhage of the pituitary gland that leads to headache, ophthalmoplegia, and altered mental status

21

ADH is primarily released by _________________.

hyperosmolar states

22

_______________ occurs in about 20% of hospitalized patients.

SIADH

23

Two endocrine disorders can cause SIADH: _______________.

hypothyroidism and hypocortisolism

24

To fit the criteria for SIADH, people must have what two lab values?

Na less than 135 mEq/L and serum osmolarity less than 275 mEq/L

25

Which side of the pituitary is bigger?

The anterior side

26

Describe the nomenclature of primary, secondary, and tertiary in endocrine disorders.

Primary: target organ fails to respond to pituitary hormone
Secondary: pituitary fails to respond to hypothalamic hormone
Tertiary: hypothalamus fails to produce hormone

27

After administering glucose, levels of ____________ should be low.

growth hormone

28

Prolactin levels greater than _____________ are indicative of prolactinoma.

150 ng/mL

29

Low TSH and low T4 indicates _________.

central hypothyroidism

30

Thinking of the anterior pituitary, what is one reason it's important for kids to get sleep?

Growth hormone secretion peaks during sleep

31

Excess FSH/LH is _______________.

rarely clinically evident

32

___________-adenomas are detected in over 80% of cases of acromegaly.

Macro

33

What can cause prolactinemia?

Use of D2 antagonists
Primary hypothyroidism
Suckling
Stalk interruption (from a mass)
Estrogen use
TCAs
Prolactinomas

34

Which layers of the adrenal cortex does ACTH act on?

All three

35

ADH deficiency is common in _____________.

metastatic cancer

36

Hypopituitarism presents with ________-kalemia.

hyper (due to loss of aldosterone from the deficient ACTH)

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