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PHYSIOLOGY III > L7: Pregnancy and Parturition > Flashcards

L7: Pregnancy and Parturition Flashcards

(75 cards)

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1
Q

meiosis II occurs at _______

A

fertilization

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2
Q

the LH surge prior to ovulation allows the meiotic arrest in the _______ follicle to be lifted

A

dominant

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3
Q

prior to ovulation, oocytes are in _______ arrest

A

meiotic

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4
Q

prior to ovulation, what keeps oocytes in meiotic arrest?

A
  • Oocyte inhibiting factor keeps oocytes in prophase I
  • Luteinizing inhibiting factors prevents granulosa cells from becoming luteal tissue
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5
Q

removal of the oocyte from ______ cells at ovulation releases the inhibition of ________

A

follicle
meiosis

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6
Q

sperm motility in the cervical canal requires an _______ pH

A

alkaline

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7
Q

sperm transportation within the uterus is assisted by ___________, facilitated by estrogen

A

myometrial contractions

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7
Q

what makes the cervix mucous watery, facilitating sperm motility

A

estrogen

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7
Q

upon reaching the ovum, sperm have to get through what two barriers

A
  • corona radiata
  • zona pellucida
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8
Q

Upon movement through female reproductive tract, sperm _______ occurs

A

capacitation
exposure of acrosomal cap

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9
Q

the semen has _______ in its ejaculate which helps move sperm within female reproductive tract

A

prostaglandins

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10
Q

ZP3 binding to ZP3 receptors initiates the _____ reaction

A

acrosomal

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11
Q

ZP___ serve to hold the sperm in place

A

ZP2

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12
Q

what is the zona reaction

A

occurs once a sperm penetrated the ZP
a fertilin on the sperm binds fertilin receptors (integrins) on the egg surface to cause in influx of Ca+ into the ovum
Ca+ influx causes depolarization and release of cortical granules to harden the ZP, blocking the entry of other sperm (polyspermy)

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13
Q

fertilization occurs within the ______

A

oviducts (fallopian tubes)

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14
Q

what prevents luteolysis in the cow and ewe

A

INF-τ
released from trophoblast

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15
Q

what does INF-τ do

A

blocks oxytocin receptors in the uterus, inhibiting the synthesis of PGF2α, thus pregnancy is recognized

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16
Q

oxytocin signaling induces a positive feedback loop causing rapid ______

A

luteolysis

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17
Q

In sows, _______ from the trophoblast serves as the signal to recognize pregnancy

A

Estrogen
this causes PGF2α to be recouted back to the uterus lumen and does not signal the CL

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18
Q

maternal recognition must occur before ______

A

luteolysis

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19
Q

luteal _____ stimulates the endometrium to secrete _______ in non-pregnant females

A

oxytocin, prostaglandin

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20
Q

prostaglandin secretion is _______ is there is an embryo present

A

suppressed

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21
Q

what hormone remains high during pregnancy

A

progesterone

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22
Q

in the mare, ______ has an LH like effect that are released from the uterus, signal to the ovary to keep the corpus luteum open

A

equine chorionic gonadotropin (eCG)

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23
_______ is released by the endometrial cups of the placenta at ~40-70 days of pregnancy
Equine Chorionic Gonadotropin (eCG)
24
in mares, this hormone enchances progesterone production by the primary CL and triggers ovulation of additional follicles to create a secondary CL
equine chorionic gonadotropin (eCG)
25
in dogs, ____ function begins autonomously and is supported by LH, followed later by _______
luteal, prolactin
26
in the dog, ____ enhances luteal activity, it is produced by either the CL or placenta depending on species. This enhances progesterone
relaxin
27
in cats, _____ and progesterone maintains the CL
relaxin
28
in dogs and cats, why is a signal from the embryo not necessary .....
CL are not lysed before normal pregnancy
29
the _______ is an organ of exange b/w maternal and fetal blood
placenta
30
what are the two hormones needed to maintain pregnancy
estrogen and progesterone
31
acts as a transient endocrine organ that secretes essential pregnancy hormones (E and P)
placenta
32
in cows, ewes and mares, the placenta takes over for the ______ in maintaining pregnancy (takes over P production)
CL
33
progesterone inhibits __________ and maintains pregnancy
myometrial contractions
34
as progesterone progresses, the number of progesterone receptors _______
decreases
35
Describe the zona reaction
* sperm penetrates zona pellucida * a fertilin on sperm can bind fertilin receptors on egg surface * influx of Ca into ovum * Ca causes depolarization and AP * release of cortical granules that harden the ZP and blocks further ZP signaling, prevents polyspermy
36
in most domestic animals, implantation occurs after several _______, during which time, significant ________ development occurs
weeks, embryonic
37
oxytocin signaling induces a ______ feedback loop causing rapid _______
positive luteolysis
38
in cows and ewes, _______ are released from the trophoblast and block _____ receptors in the uterus, inhibiting the synthesis of ______, thus pregnancy is recognized
INF- τ (interferons) oxytoxin PGF2alpha
39
in cows, serum _____ is a reliable marker of conception at days 17-20 post ovulation
INF- τ
40
in sows, ________ from the trophoblast seves as the signal to recognize pregnancy
estrogen
41
luteal _____ stimulates the endometrium to secrete ______ in non-pregnany females
prostaglandin
42
when is prostaglandin secretion suppressed
if an embryo is present
43
what hormone maintains pregnancy in all species and therefore remains high during pregnancy
Progesterone
44
in mares, _______ has an LH like effect
equine chorionic gonadotropin (eCG)
45
in mares, ______ is released by endometrial cups of the placenta
Equine chorionic gonadotropin
46
immediately after ovulation, _____ from the primary CL decreases, then it is 'reactivated' by _______ | in mares
progesterone equine chorionic gonadotropin
47
equine chorionic gonadotropin enhances _______ by the primary CL and triggers ovualtion of additional follicles to create _________
progesterone secondary CL
48
how long does the CL survive in dogs (independent of pregnancy)
60-70 days
49
in dogs, relaxin enhances _______ activity and specifically placental relaxin enhances _______
luteal progesterone
50
how long does the CL survive in cats (independent of pregnancy)
35-40 days
51
in dogs, luteal function begins autonomously and is supported by ______ followed later by ________
LH Prolactin
52
in cats, the _________ unit influences and extends luteal activity
fetal placental
53
in cats, ______ and ________ maintain the CL
relaxin and progesterone
54
implantation occurs when the endometrium is at peak __________ and secretion
thickness
55
blastocyst implantation begins when cell adhesion molecules adhere to the _______ and trophoblast enzymes erode the __________
endometrium uterine wall
56
steps in implantation
1. blastocyst adheres to endometrial lining 2. trophoblast cells invade the endometrium 3. blastocyst is completely buried in endometrium
57
what hormones does the placenta secrete
equine chorionic gonadotropin estrogen progesterone
58
in cows, ewes and mares, the ______ takes over for the CL in maintaining gestation
placenta
59
progesterone inhibits myometrial __________
contractions
60
__________promotes the endometrial gland growth, stimulates the activity of the oviduct and endometrial glands to provide nutrients
progesterone
61
in ruminants and sows, ________ increases dramatically at the end of pregnancy
estrogen
62
how does estrogen inhibit lactation in ruminants and sows
antagonizes prolactin - effect on mammary glands, suppreses milk synthesis inhibits lactalbumin - required for lactose synthesis
63
what occcurs during stage I of parturition
progesterone is converted to estradiol luteolysis PGF2alpha contributes to myometrial contractions preparation of birth canal
64
what occurs during stage II of parturition
delivery, fetus passes through pelvic canal
65
what occurs during stage III of parturition
fetal membranes are delivered, myometrial contractions help reduce uterus size and release of membranes (PGF2alpha surge)
66
what initiates stage 1 of parturition
fetal adrenal corticoids
67
what controls the timing of birth
fetal cortisol levels as fetal cortisol levels rise, progesterone levels fall
68
what are the 2 main things fetal cortisol does
activates 17α-hydroxylase to cause synthesis of estrogen rather than progesterone Causes placenta to produce PGF2α; CL regresses
69
what are the effects of fetal cortisol activating 17α-hydroxylase
* synthesis switches from making progesterone to estrogen * causes myometrium to become more active * increases secretory activity of the reproductive tract and opens the cervix
70
what are the effects of fetal cortisol causing the placenta to produce PGF2α
* CL of pregnancy regresses * stimulates synthesis of relaxin (loosens/softens birth canal) * directly stimulates myometrial activity
71
Stage II of parturition is mediated by _______ signaling
oxytocin
72
when is labor initiated
when oxytocin receptor concentration reaches a critical threshold
73
what is pitocin
pharmalogical synthetic form of oxytocin

PHYSIOLOGY III (31 decks)

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