Human Growth Hormone

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The Gonads

An informative article on: The Gonads.

Contrary to the vernacular usage of the word gonads, or its slang derivative Ďnads,í the gonads are actually the sex organs of either males or females. The slang references the testicles, but gonads are the testicles in males and the ovaries in females that have the function of producing gametes. In the testes, gametes are spermatozoon, and in the ovaries they are known as ova. In simple English, the testicles secrete sperm cells and the ovaries release eggs. They are a vital part of the endocrine system in that they are essential for the development and sustenance of life.

Regulation and Development of the Gonads

The gonads start as a single cluster of embryonic cells and donít differentiate until several weeks of fetal development. It is the presence of the SRY gene on the Y chromosome that determines the gonads to develop male characteristics. They are regulated by the luteinizing hormone and the follicle stimulating hormone that have been secreted by the pituitary gland. An over abundance or lack of those two hormones can affect the development of the gonads, and the regulation of them once they are formed.

Hormones Secreted by the Ovaries

The two important female hormones secreted by the ovaries are estrogen and progesterone. Estrogen assists in tissue growth in the sex organs as well as in other reproductive tissues. It is also necessary to the development of bones and protects the health of the heart. A lack of estrogen directly affects calcium levels in the bloodstream which is why it leads to osteoporosis and arrhythmia in heartbeats. Progesterone prepares the uterus to accept the fertilized egg and it also starts preparing the breasts to produce milk.

Hormones Secreted by the Testes

Whereas the ovaries secrete two hormones, the testes secrete on important hormone, testosterone. It is responsible for the secondary sexual characteristics of the masculine body, including hair growth on the face and body as well as the development of muscle. Testosterone is crucial in the production of sperm and also acts to strengthen bones. Of the two types of hormones (protein or steroids), testosterone is a steroid from the androgen group that is vital in the development of reproductive tissue in males. As estrogen is vital in the prevention of osteoporosis in women, testosterone is crucial to inhibit the onset in males.

It is possible to utilize replacement therapy if there is a lack of any of those vital hormones that regulate the gonads, and it is also possible to counteract increased levels that can have consequences that are just as serious. For example, although not life threatening, an overabundance of free testosterone in the bloodstream can lead to an increase in its conversion to dihydrotestosterone which is responsible for Androgenetic Alopecia and Benign Prostatic Hyperplasia, BPH. While there are some disorders of the gonads in younger persons, most often diseases and disorders donít appear until later in life near the time of menopause in women, and around the same age in men.