Hypothalamic and Ant pituitary disorders

Question 1

What hypothalamic releasing hormone stimulates release of Prl?

Answer 1

TRH

Question 2

What 3 factors act on the Anterior pituitary to regulate release of prl? #

Answer 2

TRH+
Dopamine -
Suckling +

Question 3

Prl acts on two tissues. What are they and what are the actions? #

Answer 3

Breast: breast development, milk production
Hypothalamus: lnegative feedback, GnRH suppression

Question 4

Somatostatin causes negative feedback for on the anterior pituitary downregulate release of what 2 hormones?

Answer 4

GH, TSH

Question 5

Dopamine down regulates secretion of what 2 hormones from the anterior pituitary?

Answer 5

TSH, PRL

Question 6

Name some hormones inhibited by somatostatin.

Answer 6

GH, ADH, thyrotropin(TSH)

Question 7

What is the clinical syndrome that results from deficiency of GH?

Answer 7

Children: short stature
Adults: varies

Question 8

What is the clinical syndrome that results from deficiency of FSH?

Answer 8

infertility

Question 9

What is the clinical syndrome that results from deficiency of LH?

Answer 9

Men: hypogonadism, reduced sperm count
Women: hypogonadism, amenorrhea, oligomenorrhea

Question 10

What is the clinical syndrome that results from deficiency of TSH?

Answer 10

hypothyroidism

Question 11

What is the clinical syndrome that results from deficiency of ACTH?

Answer 11

Hypoadrenalism- loss of pigmentation

Question 12

What is the clinical syndrome that results from deficiency of ADH?

Answer 12

diabetes insipidua

Question 13

What is the clinical syndrome that results from deficiency of OT?

Answer 13

Failure of milk- let down, failure of uterine contraction, post-partum bleeding?

Question 14

Why would you give both thyroxine and cortisol to someone who had anterior pituitary deficiency?

Answer 14

Thryoxine increased metabolism and that person can go into adrenal crisis due to the renal insufficiency. Always give cortisol with it.

Question 15

T or F. Thyroxine is a potent pre-puberty growth stimulator.

Answer 15

T.

Question 16

How could someone with Sheehan syndrome present? #

Answer 16

Panhypopituitarism- s/s of any or all deficiencies with the most life threatening being ACTH (GIVE CORTISOL), followed by TSH, then FSH/LH, and lastly GH.

Question 17

What is the most common secretory pituitary tumor?

Answer 17

Prolactin

Question 18

What is the effect of ant. pit. prolactinoma?

Answer 18

Females: amenorrhea, oligomenorrhea, galactorrhea, infertility, osteopenia,
Males: hypogonadism, decreased libido, galactorrhea, pit. deficiencies

#: Also impotence and gynocomastia in men.  
Bitemporal hemianopsia.

Question 19

Cause of cushing’s disease

Answer 19

Excess cortisol. Glucocorticoid therapy, ACTH producing ptiuitary adenoma, adrenocortical tumros, ectopic ACTH production

Question 20

Cause of acromegaly/gigantism?

Answer 20

GH excess

Question 21

Clinical effects of hormonal excess of gonadotropins?

Answer 21

visual disturbances, headaches, hypogonadism

Question 22

Four different things that can cause an elevated PRL

Answer 22

1. Hypothalamic dopamine def
2. Defective dopamine delivery
3. Lactotroph insensitivity to dopamine
4. Stimulation of lactotrophs. In primary hypothyroidism there is an increased TRH and TSH that could stimulate lactotrophs.

Question 23

The serum prolactin concentration is much higher in pt with a _____.

Answer 23

macro-adenoma

Question 24

What does bromocriptine do to LH and FSH activity in hyperprolactinemia?

Answer 24

Increase in frequency of LH and FSH pulses and an increased mean LH. These pt can become fertile.

Question 25

What is responsible for negative feedback on the hypothalamus to reduce GHRH release?

Answer 25

IGH1, GH, aging, disease, hyperglycemia

Question 26

What causes positive feedback on the hypothalamus to increase secretion of GHRH?

Answer 26

Sleep, stress, hypoglycemia

Question 27

What causes negative feedback on the ant. pituitary to reduce secretion of GH?

Answer 27

SS, GH, IGF1

Question 28

Is IGF1 pulsatile?

Answer 28

No. Carried by stable proteins and does NOT respond acutely to changes.

Question 29

What will happen if you give a pt with acromegaly glucose?

Answer 29

Glucose will go up, but GH does not go down like it should

Question 30

Etiology of acromegaly

Answer 30

Pituitary adenoma most commonly.

Question 31

Define gigantism#

Answer 31

Excess linear height of 2SD above mean which can occur when excess GH acts on growth plates.

Question 32

What may gigantism be associated with?#

Answer 32

McCune Albright syndrome, MEN1 (3Ps)

Question 33

What should be included in DDx with gigantism?#

Answer 33

Precocius puberty, normal genetics, hyperthyroidism

Question 34

Risk of long term GH#

Answer 34

hepatomegaly, cardiomyopathy, peripheral neuropathies, glucose intolerance and diabetes mellitus, headache due to mass effect and bitemporal hemianopsia

Question 35

Describe onset of acromegaly and gigantism.#

Answer 35

Acro: insidious, 3rd decade of life
Gig: dramatic, more acute, younger

Question 36

Is there an icnreased cancer risk in pt with excess GH?

Answer 36

Yes. Particularly colon and GI

Question 37

Describe steps you would take in diagnosing a GH secreting pituitary adenoma.

Answer 37

1. Look at IGF1 (high)
2. OGTT with GH levels (inadequate suppression of GH)
3. Pituitary MRI
   - Mass or empty sells- GH secreting pituitary adenoma
   - Normal: look at chest and abdominal CT to see if there is an extra-pituitary acromegaly

Question 38

Is sweating a common complaint with people who have acromegaly?

Answer 38

Yes

Question 39

Prognosis of Acromegaly#

Answer 39

Cardiac failure is most common cause of death. Increased risk of Colon cancer and pit. insufficiency

Question 40

Other than pituitary adenoma, what types of tumors can secrete GHRH to increase GH secretion?

Answer 40

Islet cell tumor, carcinoid tumor int he lung