Definitions for placentapləˈsɛn tə
This page provides all possible meanings and translations of the word placenta
Random House Webster's College Dictionary
pla•cen•ta*pləˈsɛn tə(n.)(pl.)-tas, -tae
the organ in most mammals, formed in the lining of the uterus by the union of the uterine mucous membrane with the membranes of the fetus, that provides for the nourishment of the fetus and the elimination of its waste products.
Category: Anatomy, Zoology
the part of the ovary of flowering plants that bears the ovules. (in ferns and related plants) the tissue giving rise to sporangia.
Origin of placenta:
1670–80; < NL: something having a flat, circular form, L: a cake < Gk plakóenta, acc. of plakóeis flat cake, der. of pláx (gen. plakós) flat
that part of the ovary of a flowering plant where the ovules form
the vascular structure in the uterus of most mammals providing oxygen and nutrients for and transferring wastes from the developing fetus
A vascular organ in mammals, except monotremes and marsupials, present only in the female during gestation. It supplies food and oxygen from the mother to the foetus, and passes back waste. It is implanted in the wall of the uterus and links to the foetus through the umbilical cord. It is expelled after birth.
In flowering plants, the part of the ovary where ovules develop; in non-flowering plants where the spores develop.
the vascular appendage which connects the fetus with the parent, and is cast off in parturition with the afterbirth
the part of a pistil or fruit to which the ovules or seeds are attached
The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and lizards with varying levels of development up to mammalian levels. Note, however, that the homology of such structures in various viviparous organisms is debatable at best and, in invertebrates such as Arthropoda, is definitely analogous at best. The word placenta comes from the Latin word for cake, from Greek plakóenta/plakoúnta, accusative of plakóeis/plakoús – πλακόεις, πλακούς, "flat, slab-like", in reference to its round, flat appearance in humans. The classical plural is placentae, but the form placentas is common in modern English and probably has the wider currency at present. In pre-Roman languages of tribal cultures, the placenta is often referred to the "little mother" or "grandmother," reflective of cultural values that revered the life mystery inherent in the childbearing process which bears fruit in the form of a child. Prototherial and metatherial mammals produce a choriovitelline placenta that, while connected to the uterine wall, provides nutrients mainly derived from the egg sac.
U.S. National Library of Medicine
A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).
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