Page 874 - Atlas of Histology with Functional Correlations

UTERUS

Consists of body, fundus, and cervix
Wall consists of outer perimetrium, middle myometrium, and inner

endometrium
Endometrium is divided into stratum functionalis and stratum basalis
During monthly menstrual cycles, stratum functionalis is shed with menstrual
flow

Endometrium morphology responds to estrogen and progesterone and
ovarian functions
Proliferative phase starts at the end of menstrual phase after estrogen release
Ovarian estrogen induces endometrial growth and formation of a new stratum

functionalis
Secretory phase starts after ovulation and corpus luteum formation
Estrogen and increased progesterone levels induce uterine gland secretion of
nutrients

Spiral arteries extend and reach the surface of endometrium
Menstrual phase starts when the ovulated oocyte is not fertilized and no
implantation occurs
Spiral arteries are highly sensitive to declining hormone levels and constrict

intermittently
Ischemia destroys the walls of blood vessels and the stratum functionalis
Dilation of spiral arteries ruptures walls, detaches functionalis, and causes
menstruation

Stratum basalis remains intact because straight arteries are not sensitive to
progesterone levels
Stratum basalis is not shed during menstruation, and blood flow is not
interrupted

Stratum basalis serves as the source of new cells for regenerating a new
stratum functionalis

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