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Physiology II Exam 3 (Lauren) > Pregnancy And Parturition > Flashcards

Pregnancy And Parturition Flashcards

(102 cards)

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1
Q

What directly determines when mesntruation occurs?

A

Drop in progesterone.

If fertilization happens, hormones don’t drop and mesntruation doesnt happen

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2
Q

What are the 4 stages of pregnancy?

A

Initiation (fertilization, implantation, secretion of HCG to rescue c.l.)

Gestation

Parturition

Lactation

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3
Q

Where does fertilization occurs?

A

Fallopian tube (usually upper third)

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4
Q

When must fertilization occur?

A

Within 24 hrs of ovulation

Sperm can survive longer 2-5 days so u can get pregnant if u have sex before ovulation

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5
Q

What does the female body do to aid in sperm migration?

A

Contractions of myometrium

Upward contractions of Fallopian tube muscle

Allurin relased by mature eggs- chemoattractant for sperms to reach egg in ampulla of Fallopian tube **

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6
Q

What is Allurin

A

The chemoattractant released by mature eggs to help allure the sperm to the egg

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7
Q

What is the optimal site of fertilization?

A

Ampulla of oviduct

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8
Q

How long after ejaculation will the sperm get into the fertilization site?

A

30-60 min

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9
Q

What percentage of the ejaculated sperm will make it to the fertilization site?

A

0.001%

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10
Q

What percentage of ejaculated sperm will even make it into the uterus?

A

0.1%

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11
Q

What is sperm capacitation?

A

As soon as the sperm gets into the female, the sperm gets “activated” via altering the surface characteristics of the sperm **

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12
Q

What is required for the sperm to be able to swim through the cervix?

A

Alkaline pH

Prostate gland secretions help with this, and estrogen helps make the mucus watery to allow them to swim

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13
Q

What causes the myometrial contractions that assist the sperm in their journey though the uterus?

A

Prostaglandins in the semen

Estrogen-primed tissue

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14
Q

What is the process of sperm capacitation?

A

While migrating through the female reproductive tract, cholesterol on the outer surface of the sperm is removed, surface proteins are removed, and calcium influx into the spermy worm increases the motility

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15
Q

How do sperm penetrate the corona radiata?

A

Its easy they just swim right through no special tricks needed.

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16
Q

What happens after sperm penetrate the corona radiata?

A

They will bind to the ZP3 protein on the zone pellucida

Acrosomal reaction occurs- hydrolysis enzymes are released onto the zone pellucida

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17
Q

What is acrosin?

A

The hydrolytic enzyme released from sperm that allow it to penetrate the zone pellucida

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18
Q

How many sperm will undergo the acrosomal reaction?

A

Hundreds of them-it requires a ton of them to degrade the zone pellucida, even though only one sperm will win

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19
Q

What is the zona reaction?

A

Its a structural change in the zona pellucida that prevents polyspermy.

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20
Q

How does the zona reaction occur?

A

The second that fertilin* on the sperm’s head binds to an integrin* receptor on the ovum’s membrane, there is a release of cortical granules that degrade ZP3 proteins and harden glycoproteins on the zona pellucida

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21
Q

What signals the ovum to complete its 2nd meiotic division and extrude the 2nd polar body?

A

Zona Reaction

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22
Q

In the zona reaction _____on the sperm’s head binds to _____ receptor on the ovums membrane

A

Fertilin

Integrin

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23
Q

Fertilized ovum divides (meiotically/mitotically_

A

Mitotically

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24
Q

At what stage is a fertilized ovum capable of implantation?

A

Blastocyst phase (1 week after fertilization)

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25
What days of the mesntrual cycle are the optimal period for implantation? Why?
Days 24-28 due to the action of progesterone (You want the progesterone to have been working for a few days making the uterus ready to make a baby) *********WAS IN RED
26
When will hCG be detectable in the serum?
After implantation is completed (8-11 days after conception)
27
What rescues the corpus luteum and keeps it from degrading into a corpus albicans when the egg was fertilized?
Placental hCG**********WAS IN RED
28
How many days after ovulation will the blastocyst enter the uterine cavity
4 days
29
How many days after ovulation will hCG rescale the corpus luteum?
10 days
30
How long after implantation does it take for the placenta to be well-established and operational
5 weeks after implantation
31
What prevents immunologic rejection of the fetus?
The placenta | ***reason why pregnant woman may be slightly immunocompromised**
32
What are the 3 hormones secreted by the placenta?
hCG- maintains corpus luteum until placenta takes over function in last 2 trimesters Estrogen- essential for maintaining normal pregancy Progesterone- essential for normal preganncy
33
What do we thing is the causative agent of morning sickness?
hCG
34
What are the actions of hCG?
Same as LH: stimulate the corpus luteum to secrete progesterone and estrogen
35
When do hCG levels decline?
When the placenta takes over the secretion of estrogen and progesterone (~3 months gestation)
36
What hormone is detected by most pregnancy tests?
hCG
37
When do hCG levels peak?
9-12 weeks gestation, then they decline to a stable plateau
38
How would hCG levels rise if there was an ectopic pregnancy?
They would rise more slowly (no placenta?)
39
How would hCG levels rise if there was a hydatidiform mole? (A noncancerous tumor that results from an unviable pregnancy)
They would rise slowly continuously (never decline)
40
What would the rise of hCG levels look like if the fetus died?
Levels would rise normally but then fall with a half life of 24 hrs
41
How does the placenta make progesterone?
ALL BY ITSELF 😀 has all the enzymes it needs to convert choleserol into progesterone
42
How does the placenta make estrogen?
In the PLACENTA: cholesterol is converted to pregnenolone In the FETAL ADRENAL GLAND**: pregnenolone converted to DHEA-Sulfate In the FETAL LIVER**: DHEA-sulfate is converted into 16-OH-DHEA-sulfate In the PLACENTA: the 16-OH-DHEA sulfate is converted to Estrogen by sulfatase and aromatase **************
43
What stimulates the fetal adrenal gland to convert pregnenolone into DHEA-sulfate?
CRH********
44
What is the most important estrogen of pregnancy?
Estriol
45
What hormone levels can we check in the moms urine to see if the fetus is healthy?
Estrogen | Estrogen synthesis is a team effort by the placenta and the fetus
46
Will the hCG message ever drop before the placenta is ready to take over making estrogen and progesterone?
No
47
What are the functions of estrogen for pregnancy?
Increased growth of myometrium-muscles for labor💪🏻 development of ductile system of breasts Stimulates prolactin release Relax and soften the pelvic ligaments (+relaxin) Inhibits lactation***!!*****!*!**!*!*
48
How does estrogen inhibit lactation’?
Antagonizes prolactin effect on the breast Inhibits lactalbumin which is required for lactose synthesis ~Everything is READY to lactate, but until the placenta is OUT of the body, she can not lactate!!~
49
Does progesterone synthesis require cholesterol from the mom’s diet
Yes
50
What is the source of progesterone during the preganncy?
First 6-12 weeks: corpus luteum After 12 weeks: placenta
51
What are the functions of progesterone during preganncy?
Conversion of uterus to secretory gland, readying it for implantation Formation of cervical plug Inhibits myometrial contraction Inhibits prostaglandin synthesis from uterus Development of alveolus and lobule in breast Inhibit lactose synthesis ***basically helps MAINTAIN pregnancy while estrogen is helping to prepare for delivery***
52
How many weeks after conception will a woman be pregnant for?
38 weeks *** | Not 40, thats when counting from the last mentstual period
53
What keeps the uterus quiet for the first 2 trimesters?
Inhibitory effects of high levels of progesterone
54
What happens to the excitability of the uterus as it moves into the 3rd trimester?
Becomes more excitable (Braxton-Hicks contractions)
55
Where does relaxin come from?
Corpus luteum of pregnancy Placenta
56
What does relaxin do?
Relaxes pelvic ligaments Softens uterine cervix
57
What are the roles of high estrogen during parturition?
Increases gap junctions between myometrial cells=uterus can contract as a coordinated unit Increased Oxytocin receptors in myometrium- uterine responds to low levels of oxytocin Increased prostaglandin production-cervical softening
58
What causes the increased oxytocin receptors in the myometrium?
Estrogen Prostaglandins
59
What could a doctor put on the cervix to soften it more
Prostaglandin gel
60
What triggers uterine contractions?
Oxytocin receptor concentration reaching a CRITICAL THRESHOLD!!**!*!*!*!*!**!*!*!*! Allows the myometrium to respond to normal/low circulating levels of OT. Then the 1st contraction happens and the levels of OT snowball (positive feedback)
61
What cases the profound effect of oxytocin on the uterus?
Increased concentration of myometrial oxytocin receptors
62
Do blood levels of oxytocin rise before labor and delivery?
NO!!! NO!!! NO!!! NO!!! NO!!!!!
63
The pregnant uterus at term is ____x more sensitive to oxytocin than nonpregnant women
100
64
What role does cortisol (from the fetus’s adrenal gland) have on the fetus?
Increases pulmonary surfactant**!!*
65
What is a serum level you could check to see how close to delivery you were?
CRH levels in mom’s blood CRH levels act as a *placental clock* for parturition ***
66
High levels of CRH are associated with (premature/late) deliveries
Premature
67
Low levels of CRH are associated with (premature/late) deliveries
Late
68
What are the 3 theories of why delivery starts?
High estrogen levels cause OT receptors to reach critical threshold CRH levels in maternal plasma act as a “Placental clock” for timing Inflammation
69
What kinds of things can increase inflammation and therefore prostaglandins and Oxytocin receptors, thus causing a premature delivery?
Multiple fetus pregnancies(increased uterine stretching) Bacterial infections Allergic reactions
70
How does inflammation induce labor?
Activation of nuclear factor in the uterus by stretching or by increased macrophages from increased pulmonary surfactant nuclear factor stimulates production of inflammatory cytokines (IL-8) and prostaglandins which promotes cervical softening
71
What is a synthetic oxytocin
Pitocin
72
What are the 3 stages of labor?
Cervical dilation- 24 hours Delivery of baby- 30-90 min Delviery of placenta- 15-30 min
73
What is the longest stage of labor?
Cervical dilation
74
What is the shortest stage of delivery?
Placenta delivery
75
What is involution of the uterus?
The uterus shrinking to its progestational size after delivery
76
Are there contractions during the delivery of the placenta’/
Yes
77
Why doesnt lactation occur during preganncy?
Inhibition from estrogen and progesterone
78
What initiates lactation?
Withdrawal of placental steroids at parturition
79
What sustains lactation?
Suckling - causes release of OT and PL so milk can be let down
80
What does oxytocin do in lactation
Milk ejection
81
What does prolactin do in lactation?
Stimulates secretion of more milk
82
What does prolactin do during gestation?
Stimulates the synthesis of milk enzymes
83
What do estrogen and progesterone do for lactation during pregancy?
Promote development of mammary glands Inhibit lactation
84
What specifically does estrogen do the the breast during pregancy
Stimulates ductal growth
85
What hormones stimulate the development of lobules and alveoli?
Progesterone Prolactin hCS (human chorionic somatomammotropin)
86
What hormones stimulate milk enzymes?
Prolactin hCS
87
What 2 weird hormones also promote lactation?
Insulin and cortisol
88
How do estrogen and progesterone inhibit lactation during preganncy?
Block the action of prolactin on the breast
89
Suckling stimulates____
Mechanoreceptors in the nipple
90
Suckling sustains the production of which 2 hormones?
Oxytocin (posterior pituitary) Prolactin (anterior pituitary)
91
What is the pathway that causes suckling to increase oxytocin production?
The Nervous pathway
92
What can stimulate the nervous pathway to release oxytocin?
Suckling Infant’s cry or smell **********
93
What can inhibit the nervous pathway and decrease oxytocin production?
Psychological stress
94
What could happen to a breastfeeding mom if she is way too stressed out?
She could inhibit the nervous pathway and not be able to make oxytocin= can’t eject milk (Making milk but cant eject it)
95
What is the major hormone responsible for lactogensis
Prolactin
96
Where does prolactin come from?
Lactotrophs in the anterior pituitary
97
What two hormones control the release of prolactin?
Thyrotropin releasing hormone (stimulatory) Dopamine (inhibitory)
98
What hormone prevents ovulation during lactation?
Prolactin*******
99
How does prolactin inhibit ovulation during lactation?
Inhibits GnRH release (no FSH or LH) | ********
100
Do lactating women have periods?
No
101
How long is ovulation suppressed?
As long as lactation continues because prolactin: Inhibits GnRH secretion Inhibits the action of GnRH on the pituitary Antagonizes the action of LH and FSH on ovaries (Its like triple redundancy)
102
Can you keep breastfeeding to prevent preganncy
Not recommended

Physiology II Exam 3 (Lauren) (5 decks)

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