6 HP Axis pt. 3

Question 1

what’s prolactin?

Answer 1

peptide hormone; promotes lactation; produced in the pituitary

Question 2

what hormones are essential for the initiation and maintenance of milk secretion?

Answer 2

PRL, cortisol

Question 3

which one has more producing cells: GH or PRL?

Answer 3

GH

Question 4

what happens to milk production when you do a hypophysectomy?

Answer 4

immediate cessation of milk production

Question 5

what happens to milk production when you do an adrenalectomy?

Answer 5

gradual reduction in milk production

Question 6

what needs to happen for milk production to happen?

Answer 6

decrease in estrogen and progesterone, which happens after giving birth

Question 7

what is perhaps the biggest regulator of PRL?

Answer 7

dopamine

Question 8

how many genes does the prolactin locus have

Answer 8

1

Question 9

what kind of receptor engages prolactin?

Answer 9

membrane; recruited

Question 10

where are prolactin receptors mainly?

Answer 10

mammary glands, but they’re also kidna everywhere

Question 11

which hormone is responsible for the synthesis and secretion of milk from alveolar epithelial cells?

Answer 11

prolactin

Question 12

which hormone is responsible for the ejection of milk?

Answer 12

oxytocin

Question 13

true or false: PRL is required for the development of the mammary gland

Answer 13

false

Question 14

what hormones play a role in duct development in the breast?

Answer 14

estrogen, GH, adrenal steroids

Question 15

what hormones play a role in alveolar growth?

Answer 15

estrogen, progesterone, adrenal steroids, PRL

Question 16

increased levels of PRL (increases/decreases) gonadotropin in males and females

Answer 16

decreases

Question 17

(high/low) levels of PRL associated with breastfeeding can lead to lactational amenorrhea

Answer 17

high

Question 18

what’s lactational amenorrhea?

Answer 18

when you’re breastfeeding you don’t have periods

Question 19

what’s a mitogen?

Answer 19

small peptide/protein that induces cell division

Question 20

what’s PRL’s significance in immunomodulation?

Answer 20

acts as a mitogen; acts on B and T cells and macrophages

Question 21

what’s the large precursor molecule of ACTH called?

Answer 21

POMC –> N-POC —> ACTH

Question 22

what enzyme cleaves POMC

Answer 22

prohormone convertase 1 (PC1)

Question 23

what hormone is related to ACTH since it’s also derived from POMC?

Answer 23

melanocyte stimulating hormone (MSH)

Question 24

what does MSH do?

Answer 24

• involved with darkening of skin by stimulating melanocytes to produce melanin to ultimately reduce UV damage
• has morphine-like activity

Question 25

where does ACTH bind?

Answer 25

receptors in adrenal gland

Question 26

what does ACTH signaling do to cholesterol?

Answer 26

enhances mobilization of cholesterol from storage; increased conversion to pregnenolone

Question 27

what G protein does ACTH activate?

Answer 27

Gsa

Question 28

what hormone controls ACTH secretion?

Answer 28

CRH

Question 29

expand CRH

Answer 29

Corticotropin-releasing hormone

Question 30

what affects CRH levels? when is it lowest?

Answer 30

circadian rhythm, stress; midnight

Question 31

expand ACTH

Answer 31

Adrenocorticotropic hormone

Question 32

an increase in ACTH will do what to cortisol levels?

Answer 32

promote

Question 33

an increase in cortisol levels will do what?

Answer 33

decrease hypothalamic and pituitary response, thereby downregulating CRH and ACTH

Question 34

expand TSH

Answer 34

thyrotropin (thyroid stimulating hormone)

Question 35

what kind of cells release TSH?

Answer 35

thyrotrophs

Question 36

what does TSH do?

Answer 36

- regulates thyroid gland using G proteins - controls formation of thyroid hormones - stimulates metabolism of thyroid follicular cells

Question 37

what kinds of cells release LH and FSH?

Answer 37

gonadotrophs

Question 38

functions of FSH?

Answer 38

females: development of ovarian follicles and estradiol secretion males: spermatogenesis, production of sex-hormone binding globulin both: secretion of inhibin (negative feedback on FSH)

Question 39

functions of LH?

Answer 39

females: steroidogenesis in follicles, induction of ovulation, maintenance of steroidogenesis by the corpus luteum males: stimulation of testosterone production on Leydig cells

Question 40

true or false: LH and FSH secretion is pulsatile

Answer 40

true

Question 41

true or false: in males, inhibin has no effect on LH

Answer 41

true

Question 42

what is the feedback effects of testosterone?

Answer 42

``` hypothalamus: pituitary: LH: FSH: they're all negative ```

Question 43

which stimulates follicular cells and which stimulates luteal cells?

Answer 43

follicular: FSH luteal: LH

Question 44

effect of LH and FSH on pituitary and hypothalamic levels?

Answer 44

mainly negative

Question 45

where is inhibin produced?

Answer 45

sertoli cells in testes and in the ovaries

Question 46

true or false: inhibin has no effect on LH secretion in females

Answer 46

true

Question 47

what is the main cause of disorders of the anterior pituitary?

Answer 47

benign tumors (adenomas)

Question 48

adenomas are (simple/difficult) to diagnose

Answer 48

difficult - symptoms are pretty generic and they accumulate

Question 49

can pituitary adenomas serve function?

Answer 49

yes, especially at younger ages. older patients typically have non-functional tumors

Question 50

what causes adenomas?

Answer 50

hypofunction, hyperfunction, or mass effect

Question 51

why is it that some adenomas cause visual field defects?

Answer 51

they impinge on optic chiasm or can extend into the cavernous sinuses

Question 52

what happens when you have a GH deficiency?

Answer 52

decreased: muscle strength, exercise tolerance, diminished libido increased: body fat

Question 53

what happens when you have a gonadotropin deficiency?

Answer 53

- oligo/amenorrhea - diminished libido - infertility - hot flashes - impotence

Question 54

what happens when you have an ACTH deficiency?

Answer 54

malaise, fatigue, anorexia, hypoglycemia

Question 55

what happens when you have TSH deficiency?

Answer 55

malaise, leg cramps, fatigue, dry skin, cold intolerance

Question 56

hypopituitarism leads to what?

Answer 56

deficiencies in hormones like GH, gonadotropin, ACTH, and TSH

Question 57

how are adenomas treated?

Answer 57

surgery through the nose :/

Question 58

over secretion of hormones from the anterior pituitary most often include which hormones?

Answer 58

PRL, GH, ACTH

Question 59

what causes adenomas that over secrete in the anterior pituitary?

Answer 59

- de novo | - lack of feedback control

Question 60

prolactinoma is usually a result of (over/under) secretion of hormones in the anterior pituitary

Answer 60

over

Question 61

what can prolactinoma lead to?

Answer 61

oligo/amenorrhea, galactorrhea, infertility, decreased libido, headaches, visual field defects

Question 62

what happens when you have an over-secretion of GH from adenomas?

Answer 62

- gigantism/acromegaly | - elevated IGFs

Question 63

expand IGF

Answer 63

insulin-like growth factor

Question 64

how are adenomas being diagnosed?

Answer 64

MRI imaging

Question 65

how do you diagnose GH deficiency?

Answer 65

insulin tolerance test, GHRH/arginine test, IGF-1 levels

Question 66

how do you diagnose gonadotropin deficiency?

Answer 66

sexual history, menstrual history, FSH/LH/estradiol/prolactin/testosterone levels

Question 67

how do you diagnose ACTH deficiency

Answer 67

AM cortisol, cosyntropin test, insulin tolerance test

Question 68

how do you diagnose TSH deficiency?

Answer 68

T4 and TSH levels

Question 69

how do you diagnose prolactinoma

Answer 69

PRL level, drug history, clinical setting

Question 70

how do you diagnose acromegaly?

Answer 70

IGF-1 level, oral glucose tolerance test

Question 71

how do you diagnose TSH overproduction?

Answer 71

free T4, T3, TSH levels

Question 72

how do you treat prolactinoma?

Answer 72

dopamine agonist therapy with bromocriptine to inhibit PRL secretion

Question 73

how do you treat acromegaly?

Answer 73

somatostatin analogs

Question 74

how do you treat deficiency states?

Answer 74

replacement of indicated hormone