Placentation

Question 1

Average gestation length of cows

Answer 1

282 days

Question 2

Average gestation length of small ruminants

Answer 2

150 days

Question 3

Gestation length in sows

Answer 3

112 - 114 days

Question 4

Average gestation length of mares

Answer 4

340 days

Question 5

Average gestation length of humans

Answer 5

284 days

Question 6

Average gestation length in mice

Answer 6

21 days

Question 7

The average gestation length of elephants (days)

Answer 7

616 days

Question 8

Name the many functions of the palcenta

Answer 8

-protection (skeletal system)
-nutrition (digestive system)
-respiration (respiratory system)
-hormone production (endocrine system)

Question 9

The innermost layer of the placenta

Answer 9

amnion

Question 10

The outermost layer of the placenta that comes into contact with the mesoderm/endometrium

Answer 10

chorion

Question 11

extension of the bladder that has fusion with the chorion

Answer 11

allantois

Question 12

What are the two ways to classify placentas?

Answer 12

-Layers
-structural components

Question 13

placental type with the most layers (6); simplest formation; present in horses, cows, pigs, ewes, whales, and deer

Answer 13

Epithelio-chorial

Question 14

Placental type with 4 layers between fetus and maternal blood; seen in dogs, bears, seals, and most carnivores

Answer 14

Endothelio-chorial

Question 15

Placental type with 3 layers; seen in rats, rabbits, humans and monkeys

Answer 15

Hemochorial

Question 16

Placental type that covers the entire surface of uterus; seen in pigs and horses

Answer 16

Diffuse

Question 17

Placental type that has a central girdle of cells; seen in dogs, ferrets and cats

Answer 17

Zonary

Question 18

Placental type with disk-shaped site on one side; seen in humans and primates

Answer 18

Discoid

Question 19

Placental type that has special sites of attachments, is noninvasive and is seen in ruminant species like cows, sheep and goats

Answer 19

Cotyledonary

Question 20

Special sites of attachment that form adjacent to caruncles

Answer 20

Cotyledons

Question 21

convex caruncles are seen in

Answer 21

cows

Question 22

concave caruncles are seen in

Answer 22

ewes

Question 23

Maternal side of placenta in ruminants

Answer 23

caruncle

Question 24

Fetal side of placenta in ruminants

Answer 24

cotyledon

Question 25

What nurtures the embryo pre-implantation?

Answer 25

cytoplasm of the zygote/blastocyst uterine and oviductal secretions

Question 26

What nurtures the embryo post-implantation?

Answer 26

Placental membranes

Question 27

stored energy and mRNA in the cytoplasm

Answer 27

Histotrophic nutrition

Question 28

Selective transfer across the placenta of AA, FAs, glucose, CO2, O2, vitamins, minerals, and electrolytes; affects the placental size and is dependent on the uterine capacity

Answer 28

Hemotrophic nutrition

Question 29

Factors affecting fetal growth

Answer 29

-genetics -environment/nutrition (mother smoking, diet of the mother; intrauterine-placental size; uterine capacity) -litter size (breed differences)

Question 30

When is exponential rate of growth of the fetus seen?

Answer 30

In the late stages of gestation

Question 31

Factors that affect gestation length

Answer 31

-Sex of fetus -number of offspring -age of dam -genetics -season (bred out of season for seasonally polyestrus species has an opposite effect on gestation length)

Question 32

Generally the older the animal the...(in terms of gestation length)

Answer 32

longer the gestation length

Question 33

Which of the following functions is not completed by the placenta? a.Induce uterine contractions b.Aid in fetal respiration c.Steroidogenesis d.Provide fetal protection e.Supply the fetus with nutrients

Answer 33

a. Induce uterine contractions

Question 34

What is the outermost fetal layer of the placenta?

Answer 34

chorionic epithelium

Question 35

What is the innermost fetal layer of the hemochorial placenta?

Answer 35

fetal endothelium

Question 36

Histotroph is a product of the uterine glands and is an important source of nutrients for the developing conceptus

Answer 36

True

Question 37

Which of the following factors listed below increases gestation length? a.Increased number of offspring b. Decreased nutrient intake c. Environmental temperature d.Sex of fetus e.Age of sire

Answer 37

d. Sex of fetus

Question 38

Which of the following species have an endothelio-chorial placenta? a.Cow b.Bitch c.Ewe d.Sow e.Mice

Answer 38

b. Bitch