The ovary, which is the female sex gland, has the function of preparing an egg cell called the “ovum.” This is involved in reproduction. Following the development of this egg cell, the ovary prepares hormones or glandular materials which go into the blood and which are significant in the functioning of a woman’s body. The periodic functions of women are largely regulated by these hormones from the ovary. The ovary, in turn, is regulated by hormones which come from the pituitary gland and which are necessary in order for ovulation to occur. Following ovulation the ovary develops a substance called the corpus luteum which provides a hormone called progesterone. Progesterone is responsible for the preparation of the uterus to receive the egg cell. When the egg cell fails to be fertilized, the uterus gets rid of the material by the usual flow.
The follicle which prepares the ovum or egg cell also is important in the formation of estrogen which is known as the female sex hormone. Although the function of the ovary was recognized as far back as 1673, only within recent years has this understanding of the glandular materials developed by the ovary come to light.
When a girl matures the flow occurs, which is usually seen between the ages of twelve and sixteen. This is a rhythmical or periodic function, taking place generally about every twenty-eight days although many cases are known in which the flow occurs at shorter or longer periods. Usually ovulation discontinues at the time of the menopause which generally takes place between forty-five and fifty-five years of age, the average being forty-eight. Estimates indicate that at the time when the girl matures there are approximately 300,000 possible egg cells ready for development. Only a few of these mature and eventually come to the surface.
After an ovum has been developed each month the follicle ruptures and the ovum travels by way of the Fallopian tubes into the uterus. If a male sex cell reaches the ovum and fertilizes it, the ovum remains in the uterus and pregnancy occurs.
In the absence of the female sex hormones, changes occur in the body of a woman which reflect the lack of these chemical regulators of the body.