. Obstetrics for nurses. o furnish a place for the implantation of the ovum, aswell as to protect the underlying maternal tissues from the invasiveaction of the fetal cells. The tubal mucosa, by contrast, undergoes littleor no decidual reaction in the presence of the fertilized ovum, so thatwhen it has penetrated beneath the epithelial layer, it is situated withinthe thin muscular wall of the tube, which is rapidly invaded by the fetalcells. At first the tube dilates to accommodate the growing product ofconception, but within a short period the limit of distensibility is reachedand the capsule
. Obstetrics for nurses. o furnish a place for the implantation of the ovum, aswell as to protect the underlying maternal tissues from the invasiveaction of the fetal cells. The tubal mucosa, by contrast, undergoes littleor no decidual reaction in the presence of the fertilized ovum, so thatwhen it has penetrated beneath the epithelial layer, it is situated withinthe thin muscular wall of the tube, which is rapidly invaded by the fetalcells. At first the tube dilates to accommodate the growing product ofconception, but within a short period the limit of distensibility is reachedand the capsule surrounding the ovum ruptures either into the lumen of 216 TEXTBOOK OF OBSTETRICS FOR NURSES the tulie or into the peritoneal cavity giving rise to a tubal abortion or atubal rupture. Tubal abortion is many times more common than rupture andgenerally occurs when the site of implantation of the ovum is in theouter third of the tube. In this event, the invasive chorionic cells at Point of rupture throughdecidua capsularis. Fig. 108.—Schematic diagram of tubal abortion. (After Bumm.) the periphery of the ovum gradually weaken the thin layer of tissuewhich separates it from the tubal lumen, and, finally, increasing tensioncauses this membrane to rupture, with the partial or complete expulsionof the product of conception. If the end of the tube is patent, the ovumand blood, which thus find their way into its lumen, are expelled into theabdominal cavity. The separation of the ovum is associated with bleed- Point of rupture—through tube wall
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectobstetrics, bookyear1
