Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

WACS > Fertility Hormones of the Hypothalamo-Pituitary-Ovarian Axis > Flashcards

Fertility Hormones of the Hypothalamo-Pituitary-Ovarian Axis Flashcards

1
Q

the 3 feedback loops of the HPO axis are

A

long, short and ultrashort

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

describe the long feedback loop

A

effects of ovarian hormones (estrogens, progesterone, inhibin) on both the hypoth (GnRH) and pituitary (FSH, LH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when is the long feedback loop inhibitory

A

in the follicular phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when is the long feedback loop stimulatory

A

in the preovulatory phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the 3 ovarian hormones involved in the long feedback loop are

A

estrogen, progesterone and inhibin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe the short feedback loop

A

effects of pituitary hormones (FSH, LH) on the GnRH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F: the short feed back is usually stimulatory

A

F. usually inhibitory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe the ultrashort feedback loop

A

Autoregulatory effect of GnRH on its own synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T/F: the ultrashort feedback loop is usually inhibitory

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F: in the follicular phase the developing follicles produce only estrogen

A

F. also small qt of progesterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the preovulatory peak of estrogen in the follicular phase is sustained for how many hours

A

24 - 48 hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when is estrogen inhibitory in the follicular phase

A

The slow and steady rise is inhibitory to GnRH, FSH and LH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

when is estrogen stimulatory in the follicular phase and to what

A

The peak state is stimulatory (causes a surge of LH - this surge is responsible for ovulation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

if pregnancy occurs, the corpus luteum produces progesterone for how long

A

10-14 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

GnRH = Gonadotropin Releasing Hormone is also known as

A

LHRH = Leuteinizing Hormone Releasing Hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T/F: GnRH is a nonapeptide

A

F. decapeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

GnRH is secreted where

A

arcuate nucleus of the hypothalamus in a pulsatile manner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

describe the GnRH pulses in the follicular and luteal phases of the ovarian cycle

A

a. 1 hourly in small amounts in the follicular phase
b. 2-3 hourly in larger amounts in the luteal phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

GnRH is modulated by these 4 mechanisms

A

ultrashort, short, long loop feedback and neurotransmitters/neuromodulators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Ultrashort feedback loop for GnRH

A
  1. High GnRH concentraion = Inhibits further GnRH secretion from the hypoth / decreases GnRH receptors in the pituitary
  2. Low GnRH concentration = Stimulates GnRH secrretion from the hypoth / increases GnRH receptors in the pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Short feedback loop for GnRH

A

FSH and LH inhibits GnRH production and secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T/F: sustained peak levels of estrogen in the preovulatory phase stimulates GnRH secretion

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Long feedback loop for GnRH

A

Estrogen and progesterone inhibit GnRH secretion except in the pre-ovulatory phase when sustained peak levels of estrogen stimulates GnRH secretion with consequent LH surge and ovlation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

the 2 catecholamines that inhibit GnRH secretion are

A

Dopamine and serotonine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

the catecholamine that stimulates GnRH secretion

A

Norepinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

the 3 endogenous opioids involved in the regulation of GnRH

A

endorphins, encephalins, dymorphins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

endorphins are increased with exercise and stress. T/F

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

T/F: the endorphins inhibit GnRH secretion

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

T/F: the endorphins stimulate dopamine secretion

A

F. inhibit dopamine secretion leading to hyperprolactinaemia due to withdrawal of dopamine inhibition on the lactotrophs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how do the endorphins cause infertility

A

They inhibit GnRH and dopamine secretion
Can lead to hypothalamic amenorrhoea and hyperprolactinaemia with subsequent infertility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

the 3 peptides involved in GnRH regulation are

A

Inhibin, follistatin, activin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

where are the peptides involved in GnRH regulation produced

A

They are produced by both pituitary cells and granulosa cells of the ovary under the influence of GnRH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

effect of activin on GnRH secretion

A

stimulates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

effect of follistatin on GnRH secretion

A

inhibits GnRH secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

effect of inhibin on GnRH secretion

A

blocks GnRH receptors on the pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

the 3 cell types of the anterior pituitary

A

chromophobes, acidophils and basophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

T/F: the chromophobes secrete prolactin

A

F. do not secrete any hormone and are called resting cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

the 2 hormones produced by acidophiles are

A

prolactin and growth hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

the hormones produced by the basophils are

A

FSH, LH, ACTH and TSH

39
Q

which of the cell types are the resting cells

A

chromophobes

40
Q

where is oxytocin produced

A

the paraventricular nucleus of the hypothalamus but transported via neurons to the posterior pituitary from where it is secreted

41
Q

T/F: the gonadotropins are peptides

A

F: water soluble glycoproteins with high molecular weights

42
Q

The alpha sub units of these 4 hormones are similar in chemistry

A

FSH, LH, TSH and hCG

43
Q

FSH levels peak at the — day of the menstrual cycle (pre-ovulatory phase) and gradually declines to its basal level around the — day

A

12th and 18th

44
Q

T/F: the gonadotropins have nuclear receptors

A

F. Their receptors occur on the cell membane surface

45
Q

T/F: the gonadotropins are secreted in pulses in response to GnRH pulses

A

T

46
Q

FSH stimulates granulosa cells to produce –, –, and –

A

inhibin A, inhibin B and activin

47
Q

T/F: FSH stimulates plasmin activator necessary for ovulation

A

T

48
Q

T/F: the LH surge triggers ovulaion, which occurs about 12 hours after LH peak

A

T

49
Q

T/F: Rising levels of estradiol, progesterone and inhibin inhibits GnRH, FSH and LH secretion

A

T

50
Q

T/F: Sustained elevated levels of estradiol stimulates GnRH and thus LH secretion (LH surge)

A

T

51
Q

T/F: prolactin is a polypeptide hormone

A

T

52
Q

T/F: Elevated prolactin levels inhibits GnRH pulses (resulting in anovulatory infertility)

A

T

53
Q

T/F: Prolactin secretion is stimulated by dopamine

A

F. inhibited

54
Q

the nonapeptide hormone of the pituitary

A

oxytocin

55
Q

‘two cell two gonadotropin theory’

A

The theory states that LH stimulaes the theca cells to produce androgens (which move into the granulosa cells) while FSH stimulates the granulosa cells to convert androgens to estrogens (by aromatization)

56
Q

least potent estrogen

A

estriol

57
Q

T/F: estrone is 10 times more potent than estriol

A

T

58
Q

describe the potency of estradiol in relation to the other estrogens

A

10 times more potent than estrone, 100 times more potent than estriol

59
Q

percentage of free and biologically active estrogen

A

1%

60
Q

percentage of estrogen bound to albumin

A

30%

61
Q

percentage of estrogen bound to SHBG

A

69%

62
Q

Estradiol (E2) and estrone (E1) are inactivated by conversion to —

A

estriol which is then conjugated in the liver and excreted in bile and urine

63
Q

T/F: cervical mucus under estrogen effect is alkaline with less protein

A

T

64
Q

T/F: Progesterone only has effect on an estrogen primed endometrium

A

T

65
Q

T/F: estrogen increases blood coagulability

A

T. Increases blood coagulability (↑Platelet adhesion; ↑fibrinogen)

66
Q

effect of estrogen on sodium and nitrogen

A

increases retention

67
Q

effect of estrogen on cholesterol

A

Lowers blood cholesterol

68
Q

T/F: estrogen raises blood levels of binding globulin, protein bound iodine and cortisol

A

T

69
Q

describe the positive feedback of estrogen LH

A

Elevated (>200pg/mL) and sustained (24-48 hours) levels of estradiol stimulates LH release (mid cycle surge) by ↑ GnRH secretion and its receptor sensitivity in the pituitary

70
Q

level of estrogen required for the positive feedback on LH

A

> 200pg/mL sustained (24-48 hours)

71
Q

T/F: Progesterone inhibits the positive feedback of estrogen on LH in the post ovulatory phase

A

T

72
Q

T/F: before ovulation, trace amounts are secreted from un-luteinized theca and granulosa cells of the developing ovarian follicle and stroma

A

T

73
Q

progesterone is metabolised in the liver and excreted in urine as

A

pregnanediol

74
Q

serum level of progesterone in the follicular phase

A

< 1ng/mL

75
Q

serum level of progesterone in the midluteal phase

A

5-25ng/mL

76
Q

percentage of progesterone bound to albumin

A

79%

77
Q

percentage of free serum progesterone

A

3.3%

78
Q

percentage of progesterone bound to steroid hormone binding globulin

A

17.7%

79
Q

T/F: progesterone acts on all estrogen primed tissues of the genital tract and the breast

A

T

80
Q

progesterone raises the basal body temperature by –

A

0.2-0.5°C

81
Q

T/F: progesterone promotes sebum secretion by skin glands

A

T

82
Q

T/F: progesterone causes fluid retention

A

T

83
Q

T/F: progesterone reduces tubal motility

A

T. Reduces tubal motility (may predispose to ectopic pregnancy)

84
Q

T/F: androgens are produced only be the theca cells of the ovary

A

F. Produced by all cells of the ovary (stromal, theca and granulosa cells) from cholesterol

85
Q

3 principal ovarian androgens are

A

dehydroepiandrosterone, androstenedione and testosterone

86
Q

describe the metabolism and excretion of ovarian androgens

A

Metabolized in the liver to 11-deoxy-7-ketosteroids (androsterone and etiocholanone) that are excreted in the urine

87
Q

the 2 androgen metabolites excreted in the urine are

A

androsterone and etiocholanone

88
Q

T/F: Inhibin - inhibits FSH secretion

A

T

89
Q

T/F: Activin - stimulates FSH secretion

A

T

90
Q

T/F: Follistatin - inhibits FSH by inhibiting activin

A

T

91
Q

AMH is produced by

A

granulosa cells of primordial (< 6mm) follicles

92
Q

T/F: AMH is a peptide hormone

A

T

93
Q

T/F: AMH levels reflect the number of developing follicles in the ovary

A

T

94
Q

T/F; AMH helps follicular development and oocyte maturation

A

T

95
Q

T/F: AMH used for testing ovarian reserve

A

T

WACS (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions