Placenta (Exam 2) Flashcards
The placenta is made up of ______ and _____ tissues, and ______ tissues are never lost.
maternal
fetal
fetal
Function of the placenta
exchange between fetus + mother
prevents mixing of blood
The placenta is a(n) (endocrine/exocrine) and _______ producing organ.
endocrine
neurotransmitter
What two things does the placenta produce which makes it an endocrine organ?
progesterone
gonadotropins
What gonadotropin does the placenta produce in horses?
eCG (equine corionic gonadotropin)
What 3 neurotransmitters can the placenta produce?
IFN-t (interferon tau)
serotonin (5-HT)
dopamine
Which neurotransmitter does the placenta produce in ruminants?
IFN-t (interferon tau)
Function of IFN-t in ruminants
prevents luteolysis (so pregnancy is maintained)
What is the significance of the placenta producing serotonin (5-HT) and dopamine?
important for fetal brain development
The placenta can produce unique proteins or __________ in cattle which has an unknown function.
PAG (pregnancy associated glycoproteins)
Placentation is the _______ and ______ of the placenta.
formation and attachment
Term for the early stage of an embryo which will eventually implant into the uterus
blastocyst
Term for nourishment of embryo from the uterine gland secretions
histiotrophe
What are the 3 sets of extraembyronic membranes that form during placentation?
- yolk sac
- amnion + chorion
- allantois
Match each extraembryonic membrane to what its derived from:
- yolk sac
- amnion + chorion
- allantois
- splanchnopleure
- somatopleure
- splanchnopleure
eCG in mares is also called ______.
PMSG (pregnant mare serum gonadotropin)
What two things does the splanchnopleure consist of?
endoderm + splanchnic mesoderm
What two things does somatopleure consist of?
ectoderm + somatic mesoderm
Splanchnic mesoderm is (avascular/vascular) and somatic mesoderm is (avascular/vascular).
vascular
avascular
The mature placenta is formed by the fusion of what two extraembryonic membranes?
chorion + allantois
Fetal blood vessels are provided by the ______ which contracts the endometrium.
allantois
What is the function of the allantois?
exchange of nutrients from maternal blood (in some species)
Hemotrophe provides nutrients from _________ while a histiotrophe provides nutrients from _________.
maternal blood
uterine glands
Two major types of placentae in domestic animals
- yolk sac placenta
- chorioallantoic placenta
Two other names for “yolk sac placenta” classification
choriovitelline placenta
omphaloid placenta
In the yolk sac placenta, the yolk sac fuses with _______.
chorion
Which species is the yolk sac placenta common in?
rodents
The chorioallantoic placenta divides into 4 sets of classes to categorize the placenta. It classifies them based on what 4 things?
maternal tissue loss
contact areas
number of layers
projections
What are the 2 classes of chorioallantoic placenta based on maternal tissue loss?
- non-deciduate
- deciduate
What is meant by “non-deciduate” placenta?
no loss of maternal tissue at birth
What is meant by “deciduate” placenta?
maternal tissue is lost at birth
Which species have a non-deciduate placenta?
pig, horse (typical in ungulates)
Which species have a deciduate placenta?
carnivores
What is unique about ruminants in terms of the class of placenta based on maternal tissue loss?
they are partially deciduous
What are the 3 classes of chorioallantoic placenta based on contact area?
- diffuse
- cotyledonary
- zonary
Term for smooth region of placenta that is not modified for exchange with the mother
chorion laeve
Term for modified region in placenta for exchange of gas, nutrients, and waste with the mother
chorion frondosum
How is the chorion frondosum modified for exchange between mother and fetus?
increased surface area (branching, villi, or folds)
The diffuse placenta is made entirely of _________.
chorion frondosum
What 3 species have a diffuse placenta?
horse
pig
camel
In the cotyledonary placenta, the fetal ______ pairs with the uterine ______ to form _______.
cotyledon
caruncle
placentome
Which species has a cotyledonary placenta?
ruminants