Fertilization, Pregnancy, Parturition, Lactation Flashcards Preview

Physiology II > Fertilization, Pregnancy, Parturition, Lactation > Flashcards

Flashcards in Fertilization, Pregnancy, Parturition, Lactation Deck (117)
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1
Q

What are the 4 stages of pregnancy?

A

initiation
gestation
parturition
lactation

2
Q

In this phase of pregnancy, the following occurs:

  • fertilization
  • implantation
  • HCG rescue of corpus luteum
A

Initiation

3
Q

What is the site of fertilization?

A

oviduct

4
Q

At what portion of the oviduct does fertilization typically occur

A

upper third

5
Q

When must fertilization occur in referance to ovulation?

A

within 24 hours of ovulation

6
Q

How long can sperm survive in the female reproductive tract?

A

5 days

7
Q

The following help what reach the oviduct?

  • contraction of myometrium
  • contraction of oviduct smooth muscle
  • Allurin release by mature eggs
A

sperm migration

8
Q

this is a chemoattractant for sperm to reach the egg in the ampulla of the oviduct…

A

allurin

9
Q

What percent of sperm reach the fertilization site, and in what timeframe?

A

0.001% within 30-60 minutes

10
Q

What percent of sperm make it to the uterus?

A

0.1 %

11
Q

This occurs when sperm pass through the female reproductive tract. It causes alteration of the surface characteristics of sperm

A

Capacitation

12
Q

sperm motility in the cervical canal requires a _____ pH

A

alkaline

13
Q

Secretions from what gland in the male reproductive tract elevate the pH?

A

prostate gland

14
Q

This hormone makes cervical mucous watery, facilitating sperm motility

A

estrogen

15
Q

_______, present in the ejaculate, promotes myometrial contractions

A

prostaglandins

16
Q

sperm acquire the ability to fertilize eggs through what process?

A

capacitation

17
Q

Sperm capacitation involves what three processes?

A

cholesterol withdrawal

redistribution of surface proteins

calcium influx

18
Q

The calcium influx in sperm capacitation has what effect?

A

increases motility

19
Q

capacitated sperm can penetrate the ______ and contact the _______ to undergo acrosome reaction

A

penetrate corona radiata

contact zona pellucida

20
Q

what does the fertilizing sperm use in order to penetrate the corona radiata?

A

plasma membrane bound enzymes

21
Q

the plasma membrane on the head of the sperm binds to which proteins on the zona pellucida?

A

ZP3 proteins

22
Q

What triggers the acrosome reaction which allows hydrolytic enzymes to be released onto the zona pellucida?

A

binding of acrosome to the ZP3 receptors

23
Q

When the sperm reaches the ovum, what happens?

A

plasma membrane fusion, DNA injection to the ovum cytoplasm

24
Q

ZP3 proteins are inactivated and proteins harden the zona pellucida when enzymes from the cortical granules are released. This prevents…

A

polyspermy (multiple fertilization)

25
Q

what enzyme is released from the acrosome which allows penetration of the zona pellucida?

A

acrosin

26
Q

sperm fusion to the ovum membrane is mediated by ____ on the sperm head and ______ on the ovum membrane

A

fertilin on sperm

integrin receptor on ovum

27
Q

This reaction is called…

release of cortical granules containing enzymes for ZP3 degradation and hardening of glycoproteins on zona pellucida…

A

zona reaction

28
Q

The zona reaction prevents…

A

polyspermy

29
Q

the zona reaction triggers what two events?

A
  1. completion of 2nd meiotic division

2. extrusion of 2nd polar body

30
Q

this process is the formation of the female nucleus and the male pronucleus…

A

fusion

31
Q

The fertilized ovum divides via…

A

mitosis

32
Q

Within a week, the fertilized ovum differntiates into a ____ which is capable of implantation

A

blastocyst

33
Q

Blastocyst impants on endometrial lining via…

A

enzymes that digest endometrium

34
Q

Days 20-24 of a regular 28 day cycle are optimal for implantation due to…

A

progesterone action

35
Q

When is hCG detectable in maternal serum?

A

after implantation, 8-11 days after conception

36
Q

What hormone rescues the corpus luteum?

A

placental hCG

37
Q

The placenta is well established and operational how long after implantation?

A

5 weeks

38
Q

The placenta performs the functions of what three systems for the fetus?

A

digestive, respiratory, renal

39
Q

the placenta acts as a transient endocrine organ that secretes what three pregnancy hormones?

A

hCG

Estrogen

Progesterone

40
Q

What two hormones released from the placenta are essential for maintaining a normal pregnancy?

A

estrogen, progesterone

41
Q

This hormone released by the placenta maintains the corpus luteum until placenta takes over function in the last two trimesters…

A

hCG

42
Q

hCG levels in maternal plasma peak between…

A

9 and 12 weeks

43
Q

What allows hCG levels to decline and corpus luteum to regress?

A

placental secretion of estrogen and progesterone

44
Q

This hormone has the same actions as LH, stimulates corpus luteum secretion of progesterone and estrogen

A

hCG

45
Q

The placenta converts maternal cholesterole to what precursor hormone of progesterone and estriol?

A

pregenolone

46
Q

Progenolone in the is taken up by the fetus, where id is converted to _____ by what gland?

A

converted to DHEA-sulfate by adrenal gland

47
Q

Fetal DHEA sulfate is converted to what by what fetal organ?

A

16-OH DHEA Sulfate by fetal liver

48
Q

Fetal 16-OH-DHEA Sulfate is transported to the placenta, where which enzyme converts it to estriol?

A

sulfatase aromatase

49
Q

Pregenolone is converted to what hormone which is sent to both the fetus and the mother?

A

progesterone

50
Q

What is the most important estrogen of pregnancy?

A

estriol

51
Q

Synthesis of this hormone requires both the fetus and the placenta…

A

estriol

52
Q

Levels of which hormone in maternal urine can be used as an index of fetal health?

A

estriol

53
Q

This hormone is responsible for developing the ductile system of breasts…

A

estrogen

54
Q

This hormone stimulates prolactin release by the anterior pituitary

A

estrogen

55
Q

this hormone relaxes and softens pelvic ligaments

A

estrogen

56
Q

This hormone inhibits lactation by antagonizing prolactin and inhibiting lactalbumin…

A

estrogen

57
Q

In the first 6-12 weeks of pregnancy, progesterone is mainly secreted by…

A

corpus luteum

58
Q

after which week does the placenta take over as the major source of progesterone secretion?

A

week 12

59
Q

This hormone converts the uterus to a secretory gland making it ready for implantation

A

progesterone

60
Q

this hormone is responsible for forming the cervical plug

A

progesterone

61
Q

this hormone inhibits myometrial contraction…

A

progesterone

62
Q

progesterone does what to prostaglandin synthesis from the uterus?

A

inhibits it

63
Q

Progesterone is responsible for the development of what two structures in the breast?

A

alveolus

lobule

64
Q

Which hormone inhibits lactose synthesis?

A

progesterone

65
Q

During gestation, volume of blood in the mother increases by…

A

30%

66
Q

respiratory activity in the mother increases by _____% in gestation

A

20%

67
Q

What keeps the uterus quiet during the first 2 trimesters?

A

inhibitor effects of progesterone

68
Q

this hormone:

  • produced by corpus luteum and placenta
  • relaxes pelvic ligaments, softens cervix
  • loosens connective tissue between pelvic bones
A

relaxin

69
Q

Parturition is made up of what three events?

A

labor, delivery, birth

70
Q

Parturition requires what two physiologic changes?

A

cervical dilation

myometrial contraction

71
Q

Do we fully understand the factors that trigger increases in uterine contractility/initiation of parturition?

A

no

72
Q

Increased estrogen results in increased ____ receptors in the myometrium

A

oxytocin receptors, increased oxytocin sensitivity

73
Q

Increased oxytocin sensitivity has what effect on uterine contractions?

A

increased

74
Q

What are three roles of high estrogen levels in labor induction?

A

Uteral gap junctions

OTR and prostaglandin synth

75
Q

increased gap junctions due to high estrogen levels allows what to occur?

A

coordinated uterine contraction

76
Q

enzymatic degradation of collagen fibers due to high estrogen levels contributes to…

A

cervical ripening

77
Q

____ must reach a critical mass for labor to begin.

A

oxytocin receptor concentration

78
Q

What is responsible for the profound effect of oxytocin at term?

A

increased myometrial OTRs

79
Q

Uterine responsiveness to oxytocin is ___x greater at term than in non-pregnant women

A

100x

80
Q

What acts as a “placental clock” for parturition?

A

CRH

81
Q

High CRH is associated with…

A

premature delivery

82
Q

low CRH is associated with…

A

late delivery

83
Q

_____ of the placenta secretes CRH to fetal circulation.

A

fetal portion of placenta

84
Q

Increased CRH in fetal circulation leads to an increase in what other fetal hormone?

A

ACTH

85
Q

Increased fetal ACTH, stimulated by CRH, stimulates release of what 2 hormones from the fetal adrenal cortex?

A

DHEA and cortisol

86
Q

DHEA from the fetal adrenal cortex increased the availabity of the placenta to convert DHEA to…

A

estrogen

87
Q

Increased fetal _____ stimulates fetal cortisol production

A

ACTH

88
Q

increased fetal cortisol due to increased ACTH leads to maturation of what fetal tissue?

A

lungs

89
Q

Critial CRH level ensures that when labor begins, the infant is ready for…

A

life outside womb

90
Q

activation of what in the uterus is caused by…

  • uterine stretching (multiple fetuses)
  • incrased production of macrophages due to increased pulmonary surfactant
A

nuclear factor (NF-kB)

91
Q

This inflammatory mediator stimulates production of cytokines and prostaglandins which promote what?

A

NF-kB, promote cervical softening

92
Q

Bacterial infx
Allergic Reaction
Multiple fetus pregancies

These can all activate what and result in premature labor?

A

NF-kB

93
Q

Is the onset of contractions a response to high, low, or normal levels of circulating oxytocin?

A

normal

94
Q

Positive-feedback by oxytocin progressively increases until what? (2)

A

cervical dilation and delivery are complete

95
Q

What is the pharmacological synthetic form of oxytocin?

A

pitocin

96
Q

Stage 1 of labor is characterized by what event, and for how long?

A

cervical dilation

few hours-24 hours

97
Q

stage 2 of labor is characterized by what event and for how long?

A

delivery of baby

30-90 minutes

98
Q

Stage 3 of labor is characterized by what event and takes how long?

A

delivery of placenta

15-30 minutes

99
Q

Delivery of a baby (stage 2) occurs when what is complete?

A

cervical dilation

100
Q

After delivery, what happens to the uterus?

A

shrinks to pregestational size (involution)

101
Q

Which hormone during gestation stimulates the synthesis of milk enzymes?

A

prolactin

102
Q

Lactation doesn’t occur in pregnancy for what reason?

A

inhibition from estrogen and progesterone

103
Q

what sustains lactation?

A

suckling

104
Q

_____ causes milk ejection while _____ stimulates secretion of more milk

A

oxytocin = ejection

prolactin = production

105
Q

What three hormones act to develop the lobules and alveoli in breast tissue?

A

progesterone

prolactin

hCG

106
Q

What two hormones stimulate milk enzymes?

A

prolactin and hCS

107
Q

Sucking and what two other factors stimulate the nervous pathway of lactation?

A

infant cry or smell

108
Q

What stimulus inhibits the nervous pathway of milk ejection?

A

psychological stress

109
Q

oxytocin is released from the posterior pituitary in the nervious pathway of lactation, which has what effect on the breast?

A

contraction of myoepithelial cells surrounding alveoli

110
Q

Prolactin stimulates what cells leading to increased milk secretion?

A

alveolar epithelial cells

111
Q

_____ stimulates prolactin release, while _____ inhibits prolactin release

A

TRH = stimulatory

DA = inhibitory

112
Q

Prolactin inhibits GnRH with prevents what?

A

ovulation

113
Q

Inhibition of GnRH inhibits the release of what two hormones leading to amenorrhea?

A

LH and FSH

114
Q

In non-lactating women, ovulation resumes in ____ weeks postpartum

A

7-10 weeks

115
Q

In lactating women, ovulation resumes with _____ months

A

7 months

116
Q

For full ovulatory suppression, how often must you breast feed?

A

regularly

117
Q

Is breast feeding a method of contraception?

A

no