ABSTRACT
This work aimed to study the contractile elements present in human term placenta. Ten normal human term placental specimens were obtained after normal deliveries. Five specimens were immersed in 4% glutaraldehyde in phosphate buffer and prepared to be examined by transmission electron microscope. The other five specimens were prepared for light microscopic examination using VVG slain. Light and electron microscopic results conformed the presence of elastic fibres, collagen bundles and myofibroblasts, in large amounts in the ground substance of the stem villous stroma. They were found in association with fetal blood vessels. Elastic fibers, collagen bundles and myofibroblasts are essential components of the stem villous stroma and form a perivascular contractile sheath around fetal blood vessels. 'This contractile sheath is suggested to play an important role in blood propulsion in human placenta
Subject(s)
Humans , Female , Microscopy, Electron , Elastic Tissue , FibroblastsABSTRACT
Five specimens were taken from normal full-term placentae immediately after delivery and other five were obtained from placentae at 10-14 weeks of gestation after therapeutic abortion. All specimens obtained were immersed in 4% glutaraldehyde in phosphate buffer and prepared to be examined by scanning electron microscopy. The study concluded that human placental villi was designed in a highly specialized pattern to allow a maximum absorptive capacity per surface area. This was achieved by a complete covering of villi by numerous microvilli, furrows in the villi to increase its surface area and an increased number of microvilli with age to face demands of growing fetus. Normal healthy placentae had no areas devoid of microvilli on the chorionic villous surface. The presence of such areas may be due to pathological conditions and most probably related to fetal biology and may have deleterious effect on the growing fetus