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Flashcards in Endocrinology of GYN Deck (98)
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1
Q

What is the hormone that the hypothalamus releases to induce LH and FSH?

A

GnRH

2
Q

What is the effect of prolactin on GnRH secretion?

A

Inhibits

3
Q

What are the basophils and acidophils of the anterior pituitary?

A

BFLAT

A PiG

4
Q

What are the three major hormones that are secreted by the ovaries?

A

Estrogen
Progesterone
Inhibins

5
Q

What is the average duration of the female menstrual cycle?

A

20-45 days, usually 28 days

6
Q

What happens, generally, to the ovaries each menstrual cycle?

A

Follicle matures and one ovum is released from the ovary each month

7
Q

What are the two major phases of the menstrual cycle?

A

Follicular phase

Luteal phase

8
Q

What are the major events in the follicular phase of the menstrual cycle? (2)

A

Follicle development

Endometrial proliferation

9
Q

What are the major events in the luteal phase of the menstrual cycle? (3)

A
  • Corpus luteum formation
  • Endometrial differentiation
  • Menses
10
Q

What are the levels of LH/FSH, estrogen, and progesterone during the follicular phase?

A

all relatively low until peak of estrogen and LH/FSH midcycle

11
Q

What are the levels of LH/FSH, estrogen, and progesterone during the luteal phase?

A

Relatively high levels of estrogen and progesterone, but baseline levels of LH and FSH

12
Q

Describe the levels of inhibins during the follicular and luteal phase of the menstrual cycle?

A

Inhibin B is at moderate levels in the follicular phase until peaks midcycle

Inhibin A is high in the luteal phase

13
Q

How is GnRH released from the hypothalamus?

A

Pulsatile release, usually ever 5-25 minutes

14
Q

What is the difference in the pulsatile release of LH/FSH in the follicular vs the luteal phase?

A

More pulses in follicular phase than in the luteal phase

15
Q

Describe the levels of estrogen throughout the menstrual cycle.

A

Moderate levels in the follicular phase before peaking mid cycle. Returns to moderate levels in the luteal phase

16
Q

Describe the levels of progesterone throughout the menstrual cycle.

A

Low throughout the follicular phase, then becomes high in the luteal phase

17
Q

When does positive feedback occur with estrogen?

A

The peak at the midcycle

18
Q

Which has a higher level of inhibition from estrogen: the pituitary or the hypothalamus

A

Pituitary

19
Q

What cells synthesize inhibin A and B?

A

Granulosa cells of the ovary

20
Q

What is the major function of inhibin A and B?

A

Negative regulation of the HPG axis

21
Q

Which is high in the follicular phase and which is high in the luteal phase: inhibin A and B

A

Inhibin A is high in the luteal phase

Inhibin B is high in the follicular phase

22
Q

What hormone does inhibin B play a role in?

A

FSH–spike leads to a reduction in FSH

23
Q

What hormone does inhibin A play a role in?

A

Secreted from the corpus luteum to inhibit LH

24
Q

What cells synthesize androstenedione in the follicular phase? What is the signal that regulates this?

A

Theca cells synthesize androstenedione in response to LH

25
Q

What cells convert androstenedione to estradiol in the follicular phase? What is the signal that regulates this?

A

Granulosa cells

Controlled by FSH

26
Q

True or false: unlike the luteal phase, there is a role for both LH and FSH in the follicular phase

A

True

27
Q

What is the G proteins that is coupled to LH receptors? FSH receptors?

A

Gs for both

28
Q

What is the effect of estrogen on the HPA axis during the follicular phase? What happens to the estrogen concentration during this phase?

A

Estrogen inhibits the HPA axis, but there is an increase in estrogen production

29
Q

What happens in the follicular phase to the granulosa cells and the theca cells?

A

Granulosa cells proliferate

Theca cells develop

30
Q

What is the role of the theca externa?

A

Capsule of the follicle

31
Q

What is the role of the theca interna?

A

Hormone producing part of the cell

32
Q

What is the role of the granulosa cells?

A

Secretion of hormones

33
Q

How many follicular cells develop during the follicular phase?

A

6-12

34
Q

What happens to the number and sensitivity of the theca and granulosa cells in the follicular phase?

A

Increased sensitivity to hormones and increase in cell number

35
Q

What are the three major events that are occurring in the follicular phase that enables an increase in estrogen despite negative feedback?

A
  1. estradiol increases expression of FSH receptors on granulosa cells
  2. Estradiol and FSH increased expression of LH receptors on theca cells
  3. Rise in estradiol and a slight rise in LH from the anterior pituitary induce proliferation of the thecal cells resulting in an increase in follicular secretion
36
Q

When the most mature of the follicles releases from the ovary during ovulation, what happens to the remaining follicles? What causes this?

A

The 5-11 immature follicles undergo atresia

This may be caused by the decline in FSH levels

37
Q

What are the cells that secrete inhibin B? What role does this play?

A

Granulosa cells

exerts a negative feedback on anterior pituitary to decrease FSH secretion

38
Q

What is the major role of estrogen on the uterine lining? Progesterone?

A

estrogen builds up the uterine lining, whilst progesterone increases differentiation

39
Q

What are the 5 major events occurring in the uterine lining with estrogen secretion during the follicular phase?

A
  • Proliferation of epithelial cells
  • Proliferation of stromal cells
  • Growth of endometrial glands
  • Blood vessel development
  • Mucus secretion
40
Q

What is the signal for ovulation to occur? When does this occur?

A

Surge in estrogen, FSH, and LH

This occurs at day 14

41
Q

How does LH promote release of the ovum from the follicle?

A

Promoting remodeling of the follicle through changes in gene expression patterns and cell signaling events

42
Q

What hormone is absolutely required for ovulation?

A

LH

43
Q

What are the three enzymes that are upregulated by follicles to allow follicular remodeling?

A
  • COX-2
  • Plasminogen activator
  • MMP
44
Q

What is the effect of progesterone on basal body temperature?

A

Increases by 0.75 ish degrees

45
Q

What forms the corpus luteum?

A

Thecal, granulosa, fibroblasts, endothelial, and immune cells

46
Q

What are the hormones that the corpus luteum produces?

A

Estradiol

Progesterone

47
Q

How long does it take for the corpus luteum to reach maturity?

A

7-8 days

48
Q

Which hormone plays the key role in steroidogenesis in the follicular phase? Luteal phase?

A

Follicular phase = FSH and LH

Luteal phase = LH

49
Q

Androstenedione is converted into estradiol in what cells during the luteal phase? What hormone controls this?

A

Luteinized granulosa cells

LH

50
Q

What is the precursor to progesterone? What happens in the luteal phase to increase this in the granulosa cells?

A

Cholesterol

Increased LDL receptors

51
Q

What is the order of arteries from the basement membrane of the uterine lining to the surface?

A

Arcuate
Radial
Straight
Spiral

52
Q

What causes the decline in progesterone and estradiol levels during the luteal phase?

A

Negative feedback on the HPA axis by progesterone and inhibin A

53
Q

When in the menstrual cycle does the corpus luteum regress? What does it turn into? What happens to steroid production at this point?

A

26th day
Corpus albicans
Decline in steroid production

54
Q

What are the chemical changes that occur in the uterus when estrogen and progesterone levels drop? (2)

A

Release of proteolytic enzymes that cause lysis of the tissues

Increases of prostaglandin production to increases myometrial contraction

55
Q

Where in the uterus does fertilization usually occur?

A

isthmus of the fallopian tube

56
Q

What is the outer layer of the oocyte? What happens to this when sperm binds?

A

Zona pellucida

Changes to prevent further fertilization by sperm

57
Q

What is the sperm+ oocyte called when it expresses enzymes that allows it to penetrate into the endometrium?

A

Blastocyst

58
Q

What are the cells on the oocyte and uterus that allows for attachment of the egg to the uterus? What mediates this attachment?

A

Trophoblast cells on oocyte
Stromal cells on the endometrium

Integrins mediate the attachment

59
Q

The trophoblasts on the oocyte differentiate into what two cell types? What is the role of each of these?

A

Cytotrophoblast

Syncytiotrophoblast

60
Q

What is the role of the syncytiotrophoblast? What do these turn into/form?

A

Sends out protrusions and invades the endometrium

Primary chorionic villi

61
Q

What are the four fetal components of the early placenta? (4)

A
  • Syncytiotrophoblasts
  • Cytotrophoblasts
  • Mesenchyme
  • Fetal blood vessels
62
Q

What is contained within the intervillous space?

A

Blood trapped between the fetal villous and maternal endometrium

63
Q

What are the maternal components of the placenta? (2)

A

Decidual cells

Maternal arteries and veins

64
Q

What is the role of hCG in pregnancy?

A

Placenta makes it, and it stimulates ovarian steroidogenesis

65
Q

After what gestational week is the maintenance of the pregnancy no longer dependent on the corpus luteum for steroid synthesis?

A

8

66
Q

What are the three main roles of progesterone in pregnancy?

A
  • inhibit prostaglandin production
  • Impact immune response
  • suppress uterine contractions
67
Q

What are the three main roles of estrogen in pregnancy?

A
  • Stimulate uterine growth
  • thicken the vaginal epithelium
  • growth and development of mammary epithelium
68
Q

hCG acts similarly to what other hormone?

A

LH–they bind to the same receptor

69
Q

After 8 weeks, what happens to hCG, estrogen, and progesterone production?

A

Switches from corpus luteum production to placental production

70
Q

What is the only hormone involved in pregnancy that the placenta does NOT secrete? What produces this?

A

DHEA

Maternal adrenal glands and fetal liver

71
Q

What cells of the placenta produce hormones?

A

Syncytiotrophoblasts

72
Q

What part produces hCG?

A

Placenta

73
Q

What part produces hPL?

A

Placenta

74
Q

What part produces CRH?

A

placenta

75
Q

What is the main role of hCG?

A

Maintains corpus luteum and thus ovarian steroid production for the first 7-8 weeks of gestation

76
Q

When does hCG become detectable? Peak?

A

6-8 days after implantation

peaks at 10 weeks

77
Q

What cells produce hCG?

A

Syncytiotrophoblast

78
Q

What is the role of hPL?

A
  • fetal metabolism
  • Fetal growth and development
  • Stimulates IGF, insulin, and surfactant production
79
Q

What cells produce hPL?

A

Syncytiotrophoblasts

80
Q

When does hPL secretion begin? What happens to levels throughout pregnancy?

A

About week 6

Increases throughout pregnancy

81
Q

What is the role of CRH?

A
  • Onset of labor
  • Prostaglandin production
  • maintain blood flow in placenta
82
Q

What cells produce CRH? What happens to levels throughout pregnancy?

A

Syncytiotrophoblasts and trophoblasts

Increases slowly throughout pregnancy, but really peaks during labor

83
Q

Draw out the cholesterol pathway

A

Draw

84
Q

What are the three major physiological roles of progesterone and 17-hydroxyprogesterone in pregnancy?

A
  • Inhibit prostaglandin production
  • Suppress uterine contractions
  • Modulate immune response
85
Q

What cells produce progesterone and 17-hydroxyprogesterone?

A

Corpus luteum for first 8 weeks, then placental syncytiotrophoblasts

86
Q

Where does the cholesterol come from for the synthesis of progesterone and 17-hydroxyprogesterone by the placental syncytiotrophoblasts?

A

Maternal LDL

87
Q

What is the role of DHEA in pregnancy?

A

Substrate for estrogen synthesis

88
Q

What cells produce DHEA in pregnancy?

A

Maternal adrenal gland

Fetal adrenal glands and liver

89
Q

What are the 6 roles of estrogen in pregnancy?

A
  • Stimulate uterine growth
  • Promote prostaglandin synthesis
  • Thicken vaginal epithelium
  • Oxytocin sensitization
  • Mammary epithelium development
  • Inhibition of milk production
90
Q

What hormone stimulates uterine growth?

A

Estrogen

91
Q

What hormone promotes prostaglandin synthesis?

A

Estrogen

92
Q

What hormone is involved in fetal growth and metabolism?

A

hPL

93
Q

What hormone increases oxytocin sensitization?

A

Estrogen

94
Q

What hormone increases mammary epithelium development, but inhibits milk production?

A

Estrogen

95
Q

What hormone maintains blood flow in the placenta?

A

CRH

96
Q

What cells produce estrogen?

A

Corpus luteum for the first 8 weeks, then syncytiotrophoblasts after

97
Q

Placental estrogen production needs androgen precursors from what?

A

Fetal adrenal gland

98
Q

Draw out last chart.

A

Draw