Placentation, Gestation, Parturition

Question 1

Temporary, metabolically active organ providing support and protection for the developing embryo/fetus, with maternal and fetal components.

Answer 1

placenta

Question 2

Outermost layer of the placenta

Answer 2

Chorion

Question 3

Cavity immediately surrounding the embryo/fetus

Answer 3

Amnion

Question 4

Cavity originating as an outpouching of the hindgut, and that is continuous with the urachus

Answer 4

Allantois

Question 5

Classification of placenta by shape

Answer 5

Diffuse - horses, pigs
Cotyledonary - cow, sheep, goats
Zonary - dog, cat
Discoid - human, mouse

Question 6

Most intimate type of placenta with only one area of attachment to mother

Answer 6

Discoid

Question 7

Classification of placenta by degree of invasiveness

Answer 7

Epitheliochorial - 6 layers with intact membranes on both sides. Horse and pig.

Syndesmochorial - Fetal-maternal syncytium.
Maternal epithelial layer missing. Cow and sheep.

Endotheliochorial - 5 layers. Dog and Cat. No uterine epithelial layer.

Hemochorial - 3 ;ayers, only fetal layers present.

Question 8

Which type of placenta allows immunoglobulins, and also pathogens, to transfer to the embryo?

Answer 8

Hemochorial

Question 9

Classification of placenta by intimacy of attachment

Answer 9

Adeciduate - horse, pig, ruminants. Loose villi, endometrium not disrupted during parturition.

Deciduate - dog, cat, human. Villi pull free and cause erosion of the endometrium during parturition.

Question 10

What type of animal has a cotyledonary, chorioallantoic, epitheliochorial/syndesmochorial, and adeciduate placenta?

Answer 10

Bovine

Question 11

What type of animal has a diffuse,chorioallantoic, epitheliochorial, and adeciduate placenta?

Answer 11

Equine

Question 12

What type of animal has a zonary, chorioallantoic, endotheliochorial, and deciduate placent?

Answer 12

Canine

Question 13

eCG in the equine is produced by what structures in the uterine wall?

Answer 13

endometrial cups

Question 14

Structure in the equine where the placenta lays against the cervix.

Answer 14

Cervical star

Question 15

Placentomes are a feature of the _____ placenta where exchange occurs, and are made up of the cotyledon and the caruncle.

Answer 15

bovine

Question 16

Species that have necrotic tips on the plaenta

Answer 16

cows, pigs

Question 17

In the canine, _____ _____ is seen on the edges of the zonary placenta

Answer 17

marginal hematoma

Question 18

What type of animal’s placenta has a 4th membrane (epithelion) for protection from friction and dehydration?

Answer 18

Camelids

Question 19

Fetal period in the bovine

Answer 19

After day 45
Fetus has organs and placenta
Period of growth (mitosis)

*at this stage will look like a small cow

Question 20

Hormones produced by the placenta

Answer 20

Progesterone
Estrogen
Relaxin
Placental lactogen
Chorionic gonadotrophin
Prolactin

Question 21

Accessory corpora lutea, which produce progesterone and are necessary to maintain pregnancy, are found in what species?

Answer 21

Equine

Question 22

In late pregnancy in the equine, ______ interacts with progesterone receptors

Answer 22

5-alpha-pregnanes

Question 23

Functions of fetal fluids

Answer 23

Protection
Nutrient reservoir
Water reservoir - friction reduction

Question 24

_______ is an absolute requirement for mammalian pregnancy.

Answer 24

Progesterone

Question 25

Where does progesterone come from?

Answer 25

Ovary | Placenta

Question 26

Functions of progesterone

Answer 26

placental development and function myometrial quiescence cervical closure immune mediation

Question 27

In what species is the corpus luteum the only source of progesterone?

Answer 27

Goat and pig

Question 28

During pregnancy, the uterine blood flow, cardiac output, and blood volume ______, but the hematocrit ______.

Answer 28

increase, decreases

Question 29

Increased insulin resistance during pregnancy can lead to

Answer 29

gestational diabetes laminitis in horses frank diabetes

Question 30

Main trigger for parturition

Answer 30

Fetal hypothalamic-pituitary-adrenal axis CRH > ACTH > cortisol release within the fetus

Question 31

With elevated fetal cortisol, final maturation of these 3 organs occurs

Answer 31

lungs, kidneys, brain

Question 32

Elevated fetal cortisol levels induce _______, which lyses the CL to bring down progesterone levels and increase estrogen levels so the uterus will start contracting.

Answer 32

P450 enzymes

Question 33

Functions of estrogen during parturition

Answer 33

Synergistic with relaxin Breaks down bonds in collagen (softening of ligaments, cervical ripening)

Question 34

Myometrial activity involves

Answer 34

smooth muscle contraction (Ca++, MLCK activation and phosphorylation) PGF2a and oxytocin (oxytocin will help muscles contract when they get tired)

Question 35

In the neonate, the main stimulus for respiratory stimulation is

Answer 35

Cold touch

Question 36

Respiratory rhythm is generated where?

Answer 36

ventrolateral medulla