endometrium

Examples of endometrium in the following topics:

• Uterine (Menstrual) Cycle

  • The uterine cycle describes a series of changes that occur to the lining of the uterus, or endometrium, during a typical menstrual cycle.
  • Several changes to the uterine lining (endometrium) occur during the menstrual cycle, also called the uterine cycle.
  • The endometrium is the innermost glandular layer of the uterus.
  • The sudden change in hormones at the time of ovulation sometimes causes minor changes in the endometrium and light midcycle blood flow.
  • Anovulatory flow that results from a very thick endometrium caused by prolonged, continued high estrogen levels is called estrogen breakthrough bleeding.

• Uterus

  • It implants into the endometrium, and derives nourishment from blood vessels which develop exclusively for this purpose.
  • The lining of the uterine cavity is called the endometrium.
  • It consists of the functional endometrium and the basal endometrium from which the former arises.
  • Damage to the basal endometrium results in adhesion formation and/or fibrosis (Asherman's syndrome).
  • In all placental mammals, including humans, the endometrium builds a lining periodically which is shed or reabsorbed if no pregnancy occurs.

• Hormonal Regulation of the Female Reproductive Cycle

  • Throughout the entire follicular phase, rising estrogen levels in the blood stimulate growth of the endometrium and myometrium of the uterus.
  • This also causes endometrial cells to produce receptors for progesterone, which helps prime the endometrium to the late proliferative phase and the luteal phase.
  • High estrogen levels initiate the formation of a new layer of endometrium in the uterus, the proliferative endometrium.
  • Progesterone plays a vital role in making the endometrium receptive to implantation of the blastocyst and supportive of the early pregnancy.

• Endometriosis

  • Endometriosis is a condition where the cells of the endometrium leak out and grow outside of the uterine cavity.
  • Endometriosis is a gynecological medical condition in which cells from the lining of the uterus (endometrium) leak out and flourish outside the uterine cavity, most commonly on the ovaries.

• Implantation

  • The syncytiotrophoblast then implants the blastocyst into the endometrium of the uterus by forming finger-like projections into the uterine wall called chorionic villi.
  • During implantation, extensions of the trophoblast, the syncytiotrophoblasts, embed within the endometrium and form chorionic villi.

• Human Gestation

  • The outer layers of the zygote (blastocyst) grow into the endometrium by digesting the endometrial cells.
  • Wound healing of the endometrium closes up the blastocyst into the tissue.
  • This ensures adequate levels of progesterone that will maintain the endometrium of the uterus for the support of the developing embryo.
  • As the trimester progresses, the outer layer of the embryo begins to merge with the endometrium and the placenta forms.

• Ovaries

  • Progesterone functions with estrogen by promoting menstrual cycle changes in the endometrium.
  • The co-actions of progesterone and estrogen promote menstrual cycle changes in the endometrium.

• Female Hormones

  • Progesterone maintains the endometrium, the lining of the uterus, to help ensure pregnancy.
  • The endometrium begins to regrow, replacing the blood vessels and glands that deteriorated during the end of the last cycle.
  • The endometrium begins to degenerate as the progesterone levels drop, initiating the next menstrual cycle.

• Fertilization

  • The zygote divides to form a blastocyst and, upon entering the uterus, implants in the endometrium, beginning pregnancy.

• Blastocyst Formation

  • The trophoblast combines with the maternal endometrium to form the placenta in eutherian mammals.