pituitary pathophys

Question 1

what hormones are secreted from the hypothalamus

Answer 1

growth hormone releasing hormone (GHRH)
corticotropin releasing hormone (CRH)
somatostatin
thyrotropin releasing hormone (TRH)

Question 2

what effect does GHRH have on pituitary

Answer 2

increases GH

Question 3

what effect does CRH have on pituitary

Answer 3

increases ACTH

Question 4

what effect does somatostatin have on pituitary

Answer 4

decreases GH and TSH

Question 5

what effect does TRH have on pituitary

Answer 5

increases TSH and prolactin

Question 6

growth hormone
secreted where

Answer 6

somatropin
anterior pituitary

Question 7

physiological effects of growth hormone

Answer 7

pro-insulin effects mediated by IGF-1 ( bone/muscle growth, protein synthesis)
anti-insulin effects mediated by GH receptor (increases blood glucose, insulin resistance, lipolysis)

Question 8

drugs for acromegaly

Answer 8

somatostatin analogs
growth hormone receptor antagonists
dopamine agonists

Question 9

drugs for hypopituitarism

Answer 9

growth hormone
IGF-1
corticosteroids
thyroid hormone
testosterone
estrogen

Question 10

MOA- decreases GH, LH, TSH, glucagon, insulin

Answer 10

somatostatin analogs:
octreotide (Sandostatin)
pasireotide (signifor)

Question 11

MOA- binds to GH receptor without activating it

Answer 11

growth hormone receptor antagonist:
somavert (pegvisomant)

Question 12

MOA- acitivaates D2 receptors
inhibits prolactin secretion

Answer 12

dopamine receptor agonists:
bromocriptine (parlodel)
cabergoline

Question 13

MOA- increases IGF-1
promotes skeletal an muscle growth
gluconeogenesis
lipolysis

Answer 13

human growth hormone:
genotropin
humatrope
norditropin/somatropin
nutropin

Question 14

MOA- stimulates growth hormone secretion from pituitary

Answer 14

GHRH receptor agonist:
macrilen (macimorelin)

Question 15

MOA- stimulates growth, tissue uptake of glucose, fatty acids and amino acids

Answer 15

recombinant human IGF-1:
increlex (mecasermin)

Question 16

how does parathyroid hormone regulate calcium

Answer 16

when Ca is low there is increased release of PTH
it increases osteoclast activity in bone causes Ca and PO release into blood
increased Ca reabsorption in kidney tubules
increased activation of Vitamin D (calcitrol) by kidneys which causes increased Ca absorption from food in small intestine

Question 17

MOA- suppress PTH secretion from chief cells, resulting in lower serum calcium levels

Answer 17

calcium receptor modulators:
cinacalet (Sensipar)
parsabiv (etelcalcetide)

Question 18

MOA- suppresses osteoclast mediated bone resorption

Answer 18

bone modulator:
alendronate

Question 19

MOA- increases renal and intestinal calcium absorption and bone turnover

Answer 19

natpara

Question 20

MOA- increases serum calcium

Answer 20

calcium carbonate

Question 21

MOA- stimulates intestinal calcium absorption and utilization

Answer 21

calcitriol (vitamin D analog)

Question 22

where is thyroglobulin (Tg) produced

Answer 22

follicular cells within the thyroid

Question 23

T4 and T3 are released

Answer 23

by Tg degradation

Question 24

2 DIT
4 iodines

Answer 24

T4

Question 25

1 DIT 1MIT 3 iodines

Answer 25

T3

Question 26

thyrotoxicosis results from elevated serum levels of T4 and T3

Answer 26

hyperthyroidism

Question 27

hyperthyroidism etiology

Answer 27

graves disease (most common)- autoantibodies stimulate TSH receptor TH secreted independently of TSH autonomous thyroid hormone secretion (goiter, adenoma)- intrinsic thyroid dysfunction TSH receptor gain of function mutation secretes TH independently of TSH diet induced (too much iodine) pituitary tumor secreting TSH- TSH secretion is unresponsive to feedback inhibition tumors co-secrete prolactin or growth hormone gestational trophoblastic tumors- HCG can stimulate the TSH receptor

Question 28

disrupted HPT axis increases TSH

Answer 28

hypothyroidism

Question 29

hypothyroidism etiology

Answer 29

dietary- iodine deficiency, cabbage, cauliflower, turnips, brussel sprouts reduced thyroid tissue (Hashimoto)- autoantibodies against TPO and/or TG lead to thyrocyte destruction infections congenital TG deficiency medications (lithium, high dose iodine) hypothalamus damage (TRH) hypopituitarism (TSH) TSH or TH resistance monodeiodinase deficiency (conversion of T4 to T3) multi nodular goiters

Question 30

MOA- suppress iodination of TG

Answer 30

TPO inhibitors/thioamids: methimazole (tapazole) propylthiouracil (propyl-thyracil/PTU)

Question 31

MOA- blocks effects of EPI and NE lowers BP by decreasing HR SM contraction in bronchioles, GI and GU tracts

Answer 31

BB: propranolol (hemangeol)

Question 32

MOA- destroys thyroid tissue by beta and gamma emission

Answer 32

radioactive oral solution: hicon (sodium iodide I-131)

Question 33

synthetic thyroid hormones

Answer 33

levothyroxine (T4; levothyroid, levoxyl, Synthroid, Tirosint, unithyroid) liothyronine (T3; cytomel) liotrix (T4 and T3; thyrolar)

Question 34

natural thyroid hormone

Answer 34

armour thyroid (4:1 mix of T4:T3)