Intervellosos

Intervellosos is a term used in some medical and anatomical texts to refer to the intervillous spaces of the placenta. The intervillous spaces are the irregularly shaped cavities found between the chorionic villi, through which maternal blood flows. These spaces form a major part of the placental intervillous system and provide the environment in which maternal blood comes into contact with the outer surface of the villi, allowing the exchange of gases, nutrients, and waste products between mother and fetus.

Etymology and designation come from the Latin roots inter- meaning between and villus (villi), reflecting their location between the placental villous projections. In Portuguese-language and some other texts, the plural adjective intervellosos is used to describe features related to these spaces.

Structure and development: The intervillous spaces are established as the placental villous tree expands and maternal spiral arteries remodel to deliver blood into the spaces. The spaces are bathed in maternal blood but are separated from fetal blood by the placental barrier, which includes the syncytiotrophoblast and fetal endothelial layers of the villous capillaries. This arrangement enables diffusion and active transport of substances while maintaining separation of circulations.

Clinical relevance: Adequate perfusion of the intervillous spaces is essential for fetal oxygenation and nourishment. Impaired perfusion or abnormalities in the intervillous spaces can be associated with conditions such as placental insufficiency and fetal growth restriction, and may be observed in placental pathologies including intervillous thrombi or hemorrhages. Understanding the intervillous spaces is important in obstetrics and placental pathology.

See also: placenta, chorionic villi, placental barrier, placental pathology.