placentation(redirected from parietal placentation)
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Related to parietal placentation: basal placentation, axile placentation
the series of events following implantation of the embryo and leading to development of the placenta.
The structural organization and mode of attachment of fetal to maternal tissues in the formation of the placenta. Types of placentation are defined under placenta.
placentation/pla·cen·ta·tion/ (pla″sen-ta´shun) the series of events following implantation of the embryo and leading to development of the placenta.
a. Formation of a placenta in the uterus.
b. The type or structure of a placenta.
placentationObstetrics The formation of the placenta in the uterus; the process by which a placenta grows and develops in the uterus. See Extrachorial placentation.
The structural organization and mode of attachment of fetal to maternal tissues in the formation of the placenta.
placentationthe arrangement of PLACENTAS (2) in the plant ovary, which can be classified into several categories including:
- (a) apical, at the ovary apex,
- (b) basal, at the ovary base,
- (c) parietal, on the ovary wall,
- (d) free-central, on a column growing up from the ovary base.
1. the series of events following implantation of the embryo and leading to development of the placenta.
2. the nature of the implantation. See also placenta.
developmental of additional areas outside the normal areas, e.g. intercotyledonary in cattle.
the areas of placentation are limited to caruncles, approximately circular masses scattered over the placenta. Characteristic of the cow, ewe and goat doe.
the whole of the surface of the chorion is placental.
abnormal placental attachments between the cotyledons, in cows.
only some zones of the placenta have a vascular area involved in placentation. Characteristic of the bitch and the queen.