07 pregnanacy Flashcards
Species with CL as sole source of progesterone
Pig Goat Llama Cat Dog
Species with CL and placental production of progesterone
Horse
Sheep
Cow
Maternal recognition of pregnancy
Luteolysis must be prevented
embryonic secretion of substances
contact with uterine epithelium
Ruminants- Maternal recognition of preg
trophoblast cells of conceptus produces INF-t between day 10-21
binds to endometrium and block synthesis of oxytocin receptors therefore oxytocin cant bind and does not stimulate endometrial production of PGF2a
Sow- Maternal recognition of preg
conceptus produces estradiol on day 13-15
estrogen causes rerouting of endometrial PGF2a into lumen of uterus and not in general circulation
Mare- Maternal recognition of preg
Conceptus must migrate around uterus!
signal not well defined
Dog- Maternal recognition of preg
None
CL maintained whether animal is pregnant or not
Cat- Maternal recognition of preg
Fetoplacental relaxin stimulates prolactin which is luteotropic and helps support CL
Roles of Placenta
nutrient exchange gas exchange stores waste protective endocrine organ
Distribution of Contact Areas
Diffuse- distributed evenly through sac horse and pig Cotyledonary- certain points of contact- maternal caruncle+fetal cotyledon=placentome ewe, cow Zonary- zone of contact dog, cat Discoid- contact in 1-2 round areas man, monkey, rodent
Degree of Invasion
Epitheliochorial 5-6 layers least invasive mare, sow, cow, sheep goat Endotheliochorial 4-5 layers carnivores Hemochorial 3 layers primates and rodents
Interdigitation of Vasculature
Simple--> Complex Folded-pig Lamellar- horses Trabecular- human Villous- cow Labyrinth- dog
Degree of Maternal tissue loss
Adeciduate- non-invasive, complete seperation of maternal and fetal tissues. Sow, mare and ruminant
Deciduate- invasive, loss of maternal tissue at parturition. Carnivores, humans, rodents
Horse-placenta type
diffuse
epitheliochorial
microcotyledonary
adeciduate
Llama- placenta type
diffuse
epitheliochorial
villous
Adeciduate
Pig–placenta type
diffuse
epitheliochorial
folded
adeciduate
Cow–placenta type
Cotyledonary
Epitheliochorial
Villous
Adeciduate
Ewe–placenta type
Cotyledonary
Epitheliochorial
Villous
Adeciduate
Goat–placenta type
Cotyledonary
Epitheliochorial
Adeciduate
Dog–placenta type
Zonary
Endotheliochorial
Labyrinth
Deciduate
Cat-placenta type
Zonary
Endotheliochorial
Labyrinth
Deciduate
Primate-placenta type
Discoidal
Hemochorial
Trabecullar
Deciduate
Mouse-placenta type
Discoidal
Hemochorial
Labyrinth
Deciduate
Ferguson Reflex
Uterine contraction–> cervical stretch–> afferent impulses from cervical stretch receptors–>reflex oxytocin secretion
