Fertilization, Pregnancy, & Parturition Flashcards Preview

Veterinary Reproduction (VEM 5111) > Fertilization, Pregnancy, & Parturition > Flashcards

Flashcards in Fertilization, Pregnancy, & Parturition Deck (47)
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1
Q

Maternal Recognition of Pregnancy in Bitches

A

No signal need

CL maintained for duration of normal gestation regardless of pregnancy status

1
Q

Yolk Sac

A

Early nutrient supply for early embryo

2
Q

Microcotelydons

A

Present on fetal side in horse pregnancy

3
Q

Allantois

A

Fuses w/ chorion

Carries blood vessels of placenta

Reservoir for nutrients & waste

Site of umbilical cord attachment

4
Q

Amnion

A

Protects fetus from injury

Lubrication for parturition

Waste reservoir

4
Q

Labyrinthine Placental Interdigitation

A

Fetal vasculature forms sponge-like configuration with maternal side

Ex. dog

5
Q

Epitheliochorial

A

5-6 layers separating maternal & fetal circulation

Ex. horses, pigs, ruminants

5
Q

Hemochorial

A

3 layers separating maternal & fetal circulation

Ex. primates, rodents

5
Q

Anencephaly in Parturition

A

Fetuses without functional brain have delayed timing of parturition (no functional control of pituitary)

5
Q

Lamellar/Microcodyledonary Placental Interdigitation

A

Elaborate folding of endometrium onto which trophoblast is draped

Ex. horse

6
Q

Maternal Recognition of Pregnancy in Queens

A

Fetoplacental relaxin may stimulate prolactin

Prolactin is luteotropic

6
Q

Puerperium

A

Time from fetal delivery until complete uterine involution

8
Q

Maternal Recognition of Pregnancy in Mares

A

Conceptus migration

Secretion of PGE2 by conceptus promotes oviductal transport

9
Q

Villous Placental Interdigitation

A

Extensive tree-like branches of fetal vasculature

Ex. cow

10
Q

Zonary Placenta

A

Most intimate contact found in belt-like area encircling conceptus

Single (dog, cat)

Double (ferret, raccoon)

11
Q

Chorion

A

Attaches to uterus

Absorbs nutrients from uterus

Maternal/fetal gas exchange

Hormone production

12
Q

Zona Block

A

Prevents multiple sperm from fertilizing oocyte (polyspermy)

Cortical granules exocytosis

Hardening of zona pellucida (ZP2, ZP3)

12
Q

Placenta (roles)

A

Nutrient exchange

Gas exchange

Stores waste

Protective

Endocrine functions

13
Q

Horse Twins

A

Foal death

Not enough room in mare uterus for both placentas to have full contact w/ maternal membranes

15
Q

Maternal Recognition of Pregnancy in Sows

A

Conceptus produces estradiol

Rerouting of endometrial PGF2alpha from circulation into lumen of uterus

16
Q

Discoid Placenta

A

Interaction found in 1 or 2 round areas

Ex. primates, rodents

17
Q

Canine - Maternal Side

A

Marginal hematomas (possible iron storage)

Stagnant maternal blood

Hemoglobin converted to green uteroverdin at parturition

18
Q

Non-deciduate/Adeciduate

A

Complete separation of maternal & fetal tissues

Ex. sow, mare, some ruminants

19
Q

Syngamy

A

Merging haploid sets of xsomes on mitotic spindle

20
Q

Sperm/Oocyte Interaction

A

Ovulation → sperm capacitation & acrosome rxn → penetration of cumulus and ZP → Zona block & Membrane block → meiotic resumption → 2nd polar body extruded → pronuclear formation → DNA synthesis → metabolic exchange → syngamy → cleavage

21
Q

Membrane/Vitelline Block

A

Prevents multiple sperm from fertilizing oocyte (polyspermy)

Changes in vitelline membrane polarization

22
Q

Folded Placental Interdigitation

A

Undulations in endometrium onto which trophoblast is draped

Ex. pig

23
Q

Cotyledonary Placenta

A

Specialized endometrium (caruncles) are in contact w/ vascularized portion of chorion (cotyledon)

Ex. ruminants

25
Q

“Tau” “cow”

Maternal Recognition of Pregnancy in Ruminants

A

Trophoblast cells of conceptus product INF-tau

INF-tau blocks endometrial synthesis of estrogen receptors & oxytocin receptors

(no stimulation of PGF2alpha)

27
Q

Fertilization

A

Male & female gametes unite to form single-celled zygote

28
Q

Prototherian

A

Egg-laying mammals

Ex. Platypus, echidnas

30
Q

Removal of Progesterone Block

A

Fetal cortisol induces placental conversion of P4 → estrogen

31
Q

Endotheliochorial

A

4-5 layers separating maternal & fetal circulation

Ex. carnivores

32
Q

Deciduate

A

Loss of maternal tissue (endometrium) at parturition

Ex. carnivores, humans, rodents

34
Q

Placenta (definition)

A

Vascular organ formed in uterus during pregnancy

Maternal & embryonic/fetal tissues

36
Q

Eutherian

A

Chorioallantoic placenta

Most mammals

37
Q

Metatherian

A

Choriovitelline (“yolk sac”) placenta

Ex. marsupials

38
Q

Trabecular Placental Interdigitation

A

Branching structures

Ex. human

39
Q

Placentome

A

Caruncle (maternal) + cotyledon (fetal)

Connected by villi

Gets larger as pregnancy progresses

41
Q

Diffuse Placenta

A

Maternal & fetal intimate contact found throughout placenta

Ex. horse, pig

41
Q

Uteroverdin

A

Hemoglobin on maternal side of the placenta turns green during parturition

Ex. canines

Green puppies!

42
Q

Stage II of Parturition

A

Fetal Expulsion:

Allantoic fluid followed by amniotic fluid

Active abdominal contractions

Fetus enters birth canal & is born

43
Q

Ferguson Reflex

A

Uterine contraction → cervical stretch → afferent impulses from cervical stretch receptors → reflex oxytocin secretion → more uterine contraction

Positive feedback loop

44
Q

Fetal HPA Axis

A

Incr. in fetal ACTH → incr. fetal cortisol → dec. P4, incr. estrogen → (PGF2alpha → luteolysis) → PGF2alpha & oxytocin → uterine contractions → Ferguson reflex → parturition

45
Q

Stage III of Parturition

A

Fetal membrane (placental) expulsion

46
Q

Oocyte Cumulus Complex (OCC)

A
  • Cumulus layer
  • Zona pellucida (ZP1, ZP2, ZP3)
  • Perivitelline space (contains 1st polar body)
  • Viteline membrane
47
Q

Stage I of Parturition

A

Preparation:

Isolation from herd

Udder (colostrum, edema)

Tissue softening

Uterus begins to make small contractions