Fertilization, Pregnancy, Parturition, Lactation Flashcards
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
what enzyme is released from the acrosome which allows penetration of the zona pellucida?
acrosin
26
sperm fusion to the ovum membrane is mediated by ____ on the sperm head and ______ on the ovum membrane
fertilin on sperm
integrin receptor on ovum
27
This reaction is called...
release of cortical granules containing enzymes for ZP3 degradation and hardening of glycoproteins on zona pellucida...
zona reaction
28
The zona reaction prevents...
polyspermy
29
the zona reaction triggers what two events?
1. completion of 2nd meiotic division
| 2. extrusion of 2nd polar body
30
this process is the formation of the female nucleus and the male pronucleus...
fusion
31
The fertilized ovum divides via...
mitosis
32
Within a week, the fertilized ovum differntiates into a ____ which is capable of implantation
blastocyst
33
Blastocyst impants on endometrial lining via...
enzymes that digest endometrium
34
Days 20-24 of a regular 28 day cycle are optimal for implantation due to...
progesterone action
35
When is hCG detectable in maternal serum?
after implantation, 8-11 days after conception
36
What hormone rescues the corpus luteum?
placental hCG
37
The placenta is well established and operational how long after implantation?
5 weeks
38
The placenta performs the functions of what three systems for the fetus?
digestive, respiratory, renal
39
the placenta acts as a transient endocrine organ that secretes what three pregnancy hormones?
hCG
Estrogen
Progesterone
40
What two hormones released from the placenta are essential for maintaining a normal pregnancy?
estrogen, progesterone
41
This hormone released by the placenta maintains the corpus luteum until placenta takes over function in the last two trimesters...
hCG
42
hCG levels in maternal plasma peak between...
9 and 12 weeks
43
What allows hCG levels to decline and corpus luteum to regress?
placental secretion of estrogen and progesterone
44
This hormone has the same actions as LH, stimulates corpus luteum secretion of progesterone and estrogen
hCG
45
The placenta converts maternal cholesterole to what precursor hormone of progesterone and estriol?
pregenolone
46
Progenolone in the is taken up by the fetus, where id is converted to _____ by what gland?
converted to DHEA-sulfate by adrenal gland
47
Fetal DHEA sulfate is converted to what by what fetal organ?
16-OH DHEA Sulfate by fetal liver
48
Fetal 16-OH-DHEA Sulfate is transported to the placenta, where which enzyme converts it to estriol?
sulfatase aromatase
49
Pregenolone is converted to what hormone which is sent to both the fetus and the mother?
progesterone
50
What is the most important estrogen of pregnancy?
estriol
51
Synthesis of this hormone requires both the fetus and the placenta...
estriol
52
Levels of which hormone in maternal urine can be used as an index of fetal health?
estriol
53
This hormone is responsible for developing the ductile system of breasts...
estrogen
54
This hormone stimulates prolactin release by the anterior pituitary
estrogen
55
this hormone relaxes and softens pelvic ligaments
estrogen
56
This hormone inhibits lactation by antagonizing prolactin and inhibiting lactalbumin...
estrogen
57
In the first 6-12 weeks of pregnancy, progesterone is mainly secreted by...
corpus luteum
58
after which week does the placenta take over as the major source of progesterone secretion?
week 12
59
This hormone converts the uterus to a secretory gland making it ready for implantation
progesterone
60
this hormone is responsible for forming the cervical plug
progesterone
61
this hormone inhibits myometrial contraction...
progesterone
62
progesterone does what to prostaglandin synthesis from the uterus?
inhibits it
63
Progesterone is responsible for the development of what two structures in the breast?
alveolus
lobule
64
Which hormone inhibits lactose synthesis?
progesterone
65
During gestation, volume of blood in the mother increases by...
30%
66
respiratory activity in the mother increases by _____% in gestation
20%
67
What keeps the uterus quiet during the first 2 trimesters?
inhibitor effects of progesterone
68
this hormone:
- produced by corpus luteum and placenta
- relaxes pelvic ligaments, softens cervix
- loosens connective tissue between pelvic bones
relaxin
69
Parturition is made up of what three events?
labor, delivery, birth
70
Parturition requires what two physiologic changes?
cervical dilation
myometrial contraction
71
Do we fully understand the factors that trigger increases in uterine contractility/initiation of parturition?
no
72
Increased estrogen results in increased ____ receptors in the myometrium
oxytocin receptors, increased oxytocin sensitivity
73
Increased oxytocin sensitivity has what effect on uterine contractions?
increased
74
What are three roles of high estrogen levels in labor induction?
Uteral gap junctions
OTR and prostaglandin synth
75
increased gap junctions due to high estrogen levels allows what to occur?
coordinated uterine contraction
76
enzymatic degradation of collagen fibers due to high estrogen levels contributes to...
cervical ripening
77
____ must reach a critical mass for labor to begin.
oxytocin receptor concentration
78
What is responsible for the profound effect of oxytocin at term?
increased myometrial OTRs
79
Uterine responsiveness to oxytocin is ___x greater at term than in non-pregnant women
100x
80
What acts as a "placental clock" for parturition?
CRH
81
High CRH is associated with...
premature delivery
82
low CRH is associated with...
late delivery
83
_____ of the placenta secretes CRH to fetal circulation.
fetal portion of placenta
84
Increased CRH in fetal circulation leads to an increase in what other fetal hormone?
ACTH
85
Increased fetal ACTH, stimulated by CRH, stimulates release of what 2 hormones from the fetal adrenal cortex?
DHEA and cortisol
86
DHEA from the fetal adrenal cortex increased the availabity of the placenta to convert DHEA to...
estrogen
87
Increased fetal _____ stimulates fetal cortisol production
ACTH
88
increased fetal cortisol due to increased ACTH leads to maturation of what fetal tissue?
lungs
89
Critial CRH level ensures that when labor begins, the infant is ready for...
life outside womb
90
activation of what in the uterus is caused by...
- uterine stretching (multiple fetuses)
- incrased production of macrophages due to increased pulmonary surfactant
nuclear factor (NF-kB)
91
This inflammatory mediator stimulates production of cytokines and prostaglandins which promote what?
NF-kB, promote cervical softening
92
Bacterial infx
Allergic Reaction
Multiple fetus pregancies
These can all activate what and result in premature labor?
NF-kB
93
Is the onset of contractions a response to high, low, or normal levels of circulating oxytocin?
normal
94
Positive-feedback by oxytocin progressively increases until what? (2)
cervical dilation and delivery are complete
95
What is the pharmacological synthetic form of oxytocin?
pitocin
96
Stage 1 of labor is characterized by what event, and for how long?
cervical dilation
few hours-24 hours
97
stage 2 of labor is characterized by what event and for how long?
delivery of baby
30-90 minutes
98
Stage 3 of labor is characterized by what event and takes how long?
delivery of placenta
15-30 minutes
99
Delivery of a baby (stage 2) occurs when what is complete?
cervical dilation
100
After delivery, what happens to the uterus?
shrinks to pregestational size (involution)
101
Which hormone during gestation stimulates the synthesis of milk enzymes?
prolactin
102
Lactation doesn't occur in pregnancy for what reason?
inhibition from estrogen and progesterone
103
what sustains lactation?
suckling
104
_____ causes milk ejection while _____ stimulates secretion of more milk
oxytocin = ejection
prolactin = production
105
What three hormones act to develop the lobules and alveoli in breast tissue?
progesterone
prolactin
hCG
106
What two hormones stimulate milk enzymes?
prolactin and hCS
107
Sucking and what two other factors stimulate the nervous pathway of lactation?
infant cry or smell
108
What stimulus inhibits the nervous pathway of milk ejection?
psychological stress
109
oxytocin is released from the posterior pituitary in the nervious pathway of lactation, which has what effect on the breast?
contraction of myoepithelial cells surrounding alveoli
110
Prolactin stimulates what cells leading to increased milk secretion?
alveolar epithelial cells
111
_____ stimulates prolactin release, while _____ inhibits prolactin release
TRH = stimulatory
DA = inhibitory
112
Prolactin inhibits GnRH with prevents what?
ovulation
113
Inhibition of GnRH inhibits the release of what two hormones leading to amenorrhea?
LH and FSH
114
In non-lactating women, ovulation resumes in ____ weeks postpartum
7-10 weeks
115
In lactating women, ovulation resumes with _____ months
7 months
116
For full ovulatory suppression, how often must you breast feed?
regularly
117
Is breast feeding a method of contraception?
no
