If you define a placenta as a structure with which a mother may transfer nutrients to its young during their development up to the moment of free-living birth, then yes. For example the common smooth-hound (Mustelus mustelus), a small shark found in the UK is viviparous (gives birth to young instead of laying eggs) and has a placental connection via an umbilical cord to its pups before they are born. Note the starry smooth-hound (Mustelus asterias) also found in the UK has no placental structure but is viviparous, providing for its young via egg sacks. The Dogfish, another UK shark, is not viviparous and its eggs are the "mermaids' purses" we find washed up on the beach.
No, tuna fish do not have placentas. The placenta is part of mammal physiology, and fish are not mammals.
Embryo's have gills to breathe inside placenta.
Placenta previa, placenta accreta, placenta increta, and placenta increta are all conditions stemming from abnormal implantation of the placenta.
Placenta comes out after each kitten.
The umbilical cord is attached to the placenta and the placenta is attached to the wall of the uterus
Yes. But the movement is relative. Placenta does not change the position. But lower placenta may move up. So that placenta previa may become normal placenta.
Yes kangaroos have a placenta.
Placenta Previa
No, lampreys do not have a placenta. They are a type of jawless fish that reproduce by laying eggs, and their young develop outside the mother's body. In contrast to mammals, which have placentas to nourish developing embryos, lampreys rely on external fertilization and do not provide maternal support during gestation.
"Unremarkable placenta" means there was nothing special, different, or noteworthy about the placenta being examined.
Placenta abruptio or placental abruption is abnormal separation of the placenta from the uterine wall.
Placenta previaThat is called "placenta previa".placenta previaPlacenta previaplacenta previa