Pregnancy recognition

Question 1

When must embryonic motility occur post ovulation in the mare to recognize pregnancy?

Answer 1

11-16 days post ovulation

Question 2

Ruminants have what mechanism to deliver PGF to the ovary?

Answer 2

Counter current exchange

Question 3

What is required for maternal recognition in the cow?

Answer 3

Interferon-tao

Question 4

What is prevented when the conceptus signals its presence?

Answer 4

luteolysis

Question 5

What hormone destroys the CL?

Answer 5

prostaglandin

Question 6

What hormone maintains pregnancy?

Answer 6

progesterone

Question 7

What secretes prostaglandin?

Answer 7

Endometrium

Question 8

What is the mechanism for luteolysis? What hormones are involved?

Answer 8

estrogen -> makes oxytocin receptors -> oxytocin binds -> prostaglandin produced

Question 9

What does progesterone block the synthesis of?

Answer 9

Oxytocin receptors

Question 10

What hormone promotes synthesis of OTR?

Answer 10

estrogen

Question 11

Species with CL as sole source of progesterone

Answer 11

Dog, Cat, pig, goat, llama

Question 12

Species with CL and placenta as source of progesterone

Answer 12

horse, sheep and cow

Question 13

What is the normal lifespan of the CL?

Answer 13

15-17 days

Question 14

What part of the female body is responsible for luteolysis?

Answer 14

uterus near ovary

Question 15

How does PGF get to the ovary in counter current exchange in all species but the mare?

Answer 15

Endometrium -> uteroovarian vein -> ovarian artery -> ovary

Question 16

How does luteolysis occur in the horse? How does PGF get to the ovary?

Answer 16

PGF travels systemically

Question 17

How does the mare recognize pregnancy?

Answer 17

movement of the conceptus

Question 18

How do the cow and sow recognize pregnancy?

Answer 18

expansion of conceptus

Question 19

What does interferon tao prevent? In what species?

Answer 19

Lutyeolysis in ruminants

Question 20

How does interferon tao work in ruminants?

Answer 20

prevents endometrium from making estrogen. Estrogen therefore cannot make OTR. Oxytocin therefore cannot bind and make PGF2a

Question 21

How long is the luteal phase in a non-pregnant cat

Answer 21

30-45 days (shorter due to lack of CL)

ovulation still occurs without conception

Question 22

How long is the luteal phase in a pregnant cat?

Answer 22

62-65 days

Question 23

Why is the luteal phase longer in the pregnant cat?

Answer 23

Conceptus makes relaxin which stimulates prolaxin which supports CL

Question 24

Fetal membranes towards maternal

Answer 24

Yolk sac: nutrition
Amnion: protection and waste
Allantois: blood supply for chorion
Chorion: gas exchange

Question 25

4 roles of placenta

Answer 25

1. nutrients 2. gas exchange 3. protection 4. stores waste

Question 26

Caruncle + cotyledon

Answer 26

Placentome

Question 27

What species have a diffuse placenta? (diffuse contact zone)

Answer 27

Mare and sow

Question 28

What species have a cotyledonary contact of placenta?

Answer 28

Cow and ewe

Question 29

What species have a zonary placental contact?

Answer 29

Dog and cat

Question 30

What are the 6 layers separating maternal and fetal

Answer 30

endothelium - CT - epithelium - epithelium - CT - endothelium

Question 31

What species have epithelialchorial layers

Answer 31

horse, pig, cow, sheep and goats

Question 32

activation of fetal HPA (hypothalmic-pituitary-adrenal axis results in an increase in fetal what?

Answer 32

ACTH and CRH | cortisol

Question 33

fetal cortisol promotes synthesis of what?

Answer 33

PGF2a | and lungs

Question 34

fetal cortisol converts what hormone into what hormone?

Answer 34

progesterone into estradiol

Question 35

what does PGF2a cause besides CL regression?

Answer 35

myometrial contractions

Question 36

what is the role of relaxin?

Answer 36

softens female tract to ease parturition

Question 37

Ferguson reflex

Answer 37

oxytocin causes contractions which releases more oxytocin

Question 38

Liggins contribution

Answer 38

fetuses control timing of parutrition

Question 39

3 stages of parturition

Answer 39

1: preparation: contractions, cervical dilation 2: fetal expulsion 3: expulsion of fetal membranes

Question 40

what does PGE from the placenta cause?

Answer 40

stimulates fetal ACTH secretion

Question 41

Puerperium

Answer 41

fetal delivery until complete uterine involution

Question 42

define lochia

Answer 42

normal postpartum debris and fluids passed with little odor

Question 43

In the cow Metestrus structure Diestrus structure proestrus structure

Answer 43

``` Met = CH Diestrus = CL Pro = CA ```

Question 44

Selected follicles secrete what 2 hormones?

Answer 44

Estradiol (help to make PGF2a) | Inhibin: negative feedback on FSH

Question 45

What does progesterone have a negative feedback on?

Answer 45

LH and FSH

Question 46

Low amounts of estradiol feedback? | Large amounts of estradiol feedback?

Answer 46

``` Low = negative feedback on FSH (some LH) High = positive on LH, cause surge ```

Question 47

in ruminants what produces PGF2a?

Answer 47

endometrium

Question 48

What makes interferon tao in the cow? What does INF-t do?

Answer 48

Trophoblast | Blocks estrogen receptor which blocks OTR

Question 49

1st uterine membrane seen | 2nd uterine membrane seen

Answer 49

1. allantois: brown | 2. amniotic: clear

Question 50

When does ovulation occur in the horse?

Answer 50

24-48 hours before end of estrus

Question 51

When does the LH surge occur in horses?

Answer 51

after ovulation

Question 52

Horse follicle size

Answer 52

40mm

Question 53

small amount of estrogen produced in mares during the winter by what?

Answer 53

adrenal gland