Page 840 - Atlas of Histology with Functional Correlations

follicle-stimulating hormone; LH, luteinizing hormone.

The female reproductive organs perform numerous functions. These include the

secretion of female sex hormones (estrogen and progesterone) for the
development of female sexual characteristics, production of oocytes, providing
suitable environment for the fertilization of the oocytes in the uterine (fallopian)
tube, transportation of the developing embryo to the uterus and its implantation,

nutrition and development of the fetus during pregnancy, and nutrition of the
newborn.

In humans, a mature ovarian follicle ovulates and releases an immature egg
called the oocyte into the uterine tube approximately every 28 days. The oocyte

remains viable in the female reproductive tract for about 24 hours, after which
the oocyte degenerates if it is not fertilized. The transformation or maturation of
the immature oocyte into a mature egg or ovum occurs at the time of
fertilization. At the moment of contact between the sperm and the cells around
the oocyte, the corona radiata, an acrosomal reaction takes place that causes the

release of the hydrolytic enzymes from the acrosome on sperm head. This action
dissolves the surrounding cell layers around the oocyte, and the sperm penetrates
the zona pellucida of the oocyte to fertilize it.

OVARIES AND DEVELOPMENT OF

FOLLICLES

Each ovary is a flattened, ovoid structure located deep in the pelvic cavity (Fig.
21.2). One section of the ovary is attached to the broad ligament by a peritoneal

fold called the mesovarium and another section to the uterine wall by an
ovarian ligament. The ovarian surface is covered by a single layer of cells
called the germinal epithelium that overlies the dense connective tissue tunica
albuginea. Inferior to the tunica albuginea is the ovarian cortex that contains the

ovarian follicles. Deep to the cortex is the vascularized, connective tissue core of
the ovary, the medulla. There is no distinct boundary line between the cortex
and medulla, and these two regions blend together.

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