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endometrium

Monday 5 July 2004

Syn. endometrial mucosa - Adj. endometrial

WKP

Components

single layer of columnar epithelium
lamina propria / stroma ( connective tissue )
endometrial glands ( tubular glands )

Images

https://commons.wikimedia.org/wiki/File:Endometrial_and_endocervical_epithelium_-_low_mag.jpg
https://commons.wikimedia.org/wiki/File:Endometrial_and_endocervical_epithelium_-_high_mag.jpg

Physiology

Morphologically, the endometrium is one of the most dynamic target tissues in women. Its cyclic structural changes mirror changes in metabolic functions, and both are regulated by ovarian estradiol and progesterone.

Because of this interplay of structure, function, and ovarian hormonal stimuli, the endometrium is considered one of the most sensitive indicators of the hypothalamic-pituitary-ovarian hormonal axis. As a result, morphologic evaluation of the endometrium is used in diagnostic evaluation of infertile patients to determine whether ovulation is occurring.

Steroid hormone control of endometrial, epithelial, stromal, and presumably endothelial cells is mediated by estrogen receptors and progesterone receptors. These steroid receptors are specific proteins concentrated exclusively in the nuclei of both endometrial epithelial and stromal cells, as well as the endothelial cells of stromal capillaries. They have high affinity to bind estradiol and progesterone, respectively.

Estradiol promotes endometrial proliferation, whereas after ovulation, progesterone converts estradiol-primed endometrium into secretory tissue. Postovulatory estradiol amplifies the progesterone effect, and after withdrawal of both estradiol and progesterone, the endometrial mucosa breaks down and regenerates within the period of menstruation.

Stages

secretory stage
proliferative stage

In the endometrial cycle

Early Secretory: POD 3 : subnuclear vacuoles and nuclei uniformly aligned