What does placental mean?
Placental is an adjective connected with the placenta, the temporary organ through which a developing mammal receives nutrients and gases from its mother and receives waste products. It is commonly used in medical and biological discussions of pregnancy, including descriptions of placental blood flow, placental hormones, placental immunity, and the placental barrier. The word is also used in zoology to distinguish placental mammals from animals that reproduce by other arrangements, such as marsupials and monotremes. Its use does not imply abnormality: in ordinary biological usage, the adjective simply describes the normal relationship between an embryo and its mother. Because the placenta is a defining feature of a major group of mammals, placental also has a broader evolutionary significance beyond human pregnancy. The term is formal and scientific, and is less common in everyday speech except when discussing pregnancy, fetal development, or mammalian classification.
adjectiveRelating to the placenta, the organ that connects a developing embryo to the uterine wall and facilitates exchange between mother and fetus. In zoology, the term also describes mammals whose embryos develop with the support of a placenta.
- Relating to the placenta or its structure, function, or biology.
- Denoting a mammal whose embryonic development involves a placenta.
"The researchers studied how placental blood flow changes throughout pregnancy."
"Placental transfer of antibodies can provide temporary protection to a newborn."
"Placental mammals include animals as diverse as bats, whales, rodents, and humans."
The word “placental” points to one of biology’s great evolutionary distinctions: mammals whose young are nourished through a placenta.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does placental come from?
The word comes through English from the Latin placenta, a term derived from placent-, meaning “cake” or “flat cake,” because the organ was thought to resemble a flat cake. The adjective placental was formed in English with the suffix -al, meaning “relating to.” The same root appears in placentation, the formation and arrangement of the placenta, and in placentary, another word relating to the placenta.
How placental is actually used
The adjective is standard in biological and medical writing. When used as a noun, it is usually used in the phrase “placental mammal” or informally to refer to such a mammal.
Easily confused with placental
Placenta is the organ itself, whereas placental is an adjective describing something related to that organ.