Scientists watch evolution in action

(PhysOrg.com) -- The yellow-bellied three-toed skink (Saiphos equalis) is one of only three reptiles known to have different methods of reproduction in different places. In the coastal areas of New South Wales (NSW), near ...

Solving the puzzle of Henry VIII

Blood group incompatibility between Henry VIII and his wives could have driven the Tudor king's reproductive woes, and a genetic condition related to his suspected blood group could also explain Henry's dramatic mid-life ...

Biologists link sexual selection and placenta formation

Sexual selection refers to species' selection for traits that are attractive to the opposite sex. This special type of natural selection enhances opportunities to mate, the tail of male peacocks being an iconic example.

Study: How placentas evolved in mammals

The fossil record tells us about ancient life through the preserved remains of body parts like bones, teeth and turtle shells. But how to study the history of soft tissues and organs, which can decay quickly, leaving little ...

Study shows placenta truly is a bacteria-free zone

A team of researchers at the University of Cambridge has found evidence indicating that the human placenta is a sterile environment. In their paper published in the journal Nature, the group describes their study of the placental ...

page 1 from 4

Placenta

The placenta is an organ unique to mammals that connects the developing fetus to the uterine wall. The placenta supplies the fetus with oxygen and food, and allows fetal waste to be disposed of via the maternal kidneys. The word placenta comes from the Latin for cake, from Greek plakóenta/plakoúnta, accusative of plakóeis/plakoús - πλακόεις, πλακούς, "flat, slab-like", referring to its round, flat appearance in humans. Protherial (egg-laying) and metatherial (marsupial) mammals produce a choriovitelline placenta that, while connected to the uterine wall, provides nutrients mainly derived from the egg sac. The placenta develops from the same sperm and egg cells that form the fetus, and functions as a fetomaternal organ with two components, the fetal part (Chorion frondosum), and the maternal part (Decidua basalis).

This text uses material from Wikipedia, licensed under CC BY-SA