Page 868 - Atlas of Histology with Functional Correlations

FIGURE 21.20 ■ Uterine wall: early menstrual phase. Stain: hematoxylin and
eosin. Low magnification.

FUNCTIONAL CORRELATIONS 21.4 ■ Uterus

The endometrium exhibits cyclic changes in its structure and function in
response to the ovarian hormones estrogen and progesterone. The uterine
changes are associated with impending implantation and nourishment of the

developing embryo. Secretion of progesterone by the functioning corpus
luteum prepares the uterus for implantation of the embryo, formation of the
placenta, and creation of a suitable environment for the development and

maturation of the offspring. However, if fertilization of the oocyte and
implantation of the embryo do not occur, the functionalis layer of
endometrium is shed as part of the menstrual flow or discharge. With each
menstrual cycle during the reproductive period, the endometrium passes

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