Lecture 8 placenta Flashcards
5 functions of placenta
protection nutrition respiratory excretory endocrine
the total nutriment supplied to the embryo
embyrotrophe
nutriment from endometrial glands
histotrophe
nutriment from maternal blood
hemotrophe
components of fetal membrane
yolk sac
amnion
allantois
chorion
components of the placenta
fetal membrane
maternal endometrium
cells that surround the blastocyst
trophoblast
what does trophoblast turn into
extra embryonic and fetal membrane
ICM turns into
amniotic cavity
hypoblast
epiblast
what is gastrulation
epiblast turning into ectoderm, mesoderm and endoderm
term for ectoderm with underlying mesoderm
somatopleure
folds in somatopleure become ___ and ____
amnion and chorion
explain amnion
part of placenta that directly encases the embryo
-space within called amniotic cavity which is filled with amniotic fluid
what is chroion
part of placenta that directly interacts with uterus
- made of ectoderm lined by mesoderm
the term for amnion fused with allantois
mesamnion
what is important about mesamnion
amnion will rip and stay connected to allantois, baby born not covered in amnion. Cattle and Sheep
term for endoderm and mesoderm
splanchnopleure
out pouching of the hindgut that hold excretions from fetus
allantois
the allantois expands and eventually contacts the chorion and forms the
chorioallantois
mesoderm is highly vascular and forms the
umbilical cord
umbilical make up
2 arteries
1 vein
part of placenta that has direct connection with endometrium of uterus
chorion
allantois, chorion and endometrium
uteroplacental unit
when yolk sac and chroion are adjacent
chroiovitelline placenta
three ways placenta is classified
shape
microscopic layers
amount of tissue lost
describe diffuse
entire surface of chorion is covered in microcotyledon that are microville that project into crypts(microcaruncles) of the endometrium except for over gland openings or cervical star in the horse
velvety
pig, horse
describe cotyledonary
cotyledon on chorion and caruncles on endometrium form placentome
very efficient
ruminants: cattle. sheep and goats
what is the connective structure of the chorion
cotyledon
what is the connective structure of the endometrium
caruncle
what is chorion and caruncle together
placentome
cows have how many placentome
75-125, mushrooms(convex)
sheep have how many placentome
80-90, concave
shape of placentome in goats
flat
describe zonary
band of chorionic fondosum that is in middle of chorionic sac
labyrinthine or lamellae structures
can form blood clots( green) at borders
dogs and cat
6 layers of embryo
epitheliochorial
example of epitheliochorial
mare and sow
fetal vessel fetal mesenchyme trophoblast uterine epithelium uterine mesenchyme uterine vessel
4 layers of embryo
endotheliochorial
endotheliochorial
fetal vessel
fetal mesenchyme
trophoblast
uterine vessel
hemochorial
fetal vessel
fetal mesenchyme
trophoblast
bathed in the blood of their mother
3 layers of embryo name
hemochorial
when maternal epithelium and submucosa are lost at parturition, leaving a denuded endometrium
deciduate
deciduate
primates
when maternal epithelium and submucosa are lost at parturition, leaving a denuded endometrium
indeciduate
mare, sow
fetal membranes expelled, endometrium intact
fetal membranes expelled, endometrium intact
indeciduate
types of shape of placentas
diffuse - mare
cotyledonary- cow
zonary- dog
discoidal- human
