Female Placentation

Question 1

reproduction occurs at the interface of?

Answer 1

aquatic and terrestrial (air) environments

Question 2

what does a fetus need? (5)

Answer 2

-protective environment
-shock absorbing
-oxygen, nutrition
-transfer of maternal immunity
-waste removal

Question 3

amniotes include:

Answer 3

tetrapod vertebrates:
- amphibians
- reptiles
- mammals

Question 4

what is the division of mammals

Answer 4

prototheria and theria (theria subdivided into metatheria and eutheria)

Question 5

what type of mammals are placental mammals

Answer 5

eutheria (a type of theria)

Question 6

what are the initial steps of organization of the embryo (very early on)

Answer 6

zygote (fertilized ovum) -> morula (16+ cells) -> blastula (consisting of the blastema and the blastocoel) -> blastocyst

Question 7

the chorion = ____________ + ________________

Answer 7

trophoblasts + mesoderm

Question 8

trophoblasts are in contact with

Answer 8

the mother

Question 9

what does the endoderm become

Answer 9

the gut and yolk sac

Question 10

the umbilical cord = _________, ___ arterie(s) and ___ vein(s)

Answer 10

urachus; 2 arteries; 1 vein

Question 11

what are the definitions of when an embryo becomes a fetus

Answer 11

1) when it starts to move
2) when you can identify the species

Question 12

the blood supply of the placenta is (volume/pressure)

Answer 12

high volume, low pressure

Question 13

what types of animals have yolk-sac prominent placentas

Answer 13

1) carnivores
2) marsupials
3) rodents and lagamorphs

Question 14

what is the role of the endometrial glands

Answer 14

secrete histotroph that the chorioallantois picks up

Question 15

what are the 4 main placental structures

Answer 15

1) chorion and arrangement
2) allantoic cavity and membrane
3) amniotic cavity and membrane
4) umbilical cord and components

Question 16

describe the chorion arrangement in the following species:
1) pig
2) equine
3) ruminant
4) carnivore

Answer 16

1) pig: villus - uterine milk - histotroph
2) equine: microcotyledonary - uterine milk - histotroph
3) ruminant: cotyledonary - haemotroph
4) carnivore: zonary - haemotroph

Question 17

describe the structures of the umbilical cord (the urachus, arteries and veins)

Answer 17

urachus: from bladder to allantois
2 arteries: from iliac arteries
1 vein: to ductus venosis - through liver to vena cava

Question 18

what is unique about the porcine placenta

Answer 18

contains tiny villi (that interdigitate with the endometrium) and larger chorionic cysts (where uterine milk is taken up)

Question 19

if in horses the microcotyledons are the trees, what are its leaves

Answer 19

trophoblasts

Question 20

what component of the placentome is maternal and what component is fetal

Answer 20

maternal: caruncle
fetal: cotyledon

Question 21

Common embryonic remnants

Answer 21

-Meckels diverticulum – small intestine – yolk sac
-Yolk sac remnant in horse
-Persistent urachus
-Round ligaments of bladder (umbilical arteries)
-Falciform ligament (umbilical vein)