The gonads are the gonads of humans that perform both exocrine and endocrine functions and play a major role in reproduction. In addition to germ cells, the gonads produce sex hormones that regulate reproduction. Diseases of the gonads often manifest as overproduction or underproduction.
What is the gonad?
The gonads are the male and female gonads. They are also called sex glands and correspond to the testes (testis) in males. In women, the gonads are the ovaries. In addition to sex hormones, the gonads produce the germ cells (gametes) for reproduction. These are haploid cells that correspond to sperm in males and eggs in females. The male gonads are in pairs and are located together with the epididymis in the so-called scrotum. In addition to sperm, they produce testosterone. The paired ovary of the female forms eggs and expels them month after month to renew them from sexual maturity. The gonads are among the abdominal and pelvic viscera and develop during embryogenesis. For both sexes, the first steps of this development are the same. However, on the Y chromosome lies the so-called SRY, which determines the testis-determining factor (TDF) and thus can initiate the development of testes. If this development is not initiated, the gonadal anlagen become the ovary.
Anatomy and structure
The ovary in women is located in a depression of tissue (fossa ovarica) in the lesser pelvis. The so-called ligamentum suspensorium ovarii connects the ovary to the lateral pelvic wall. The ligamentum ovarii proprium provides a connection to the uterus. The ovary is up to five centimeters long and up to one centimeter thick. It is almond-shaped and convex on both sides. At sexual maturity, the surface changes from smooth to vesicular as ovarian follicles form. The ovary is innervated vegetatively by the superior mesenteric plexus and the renal plexus. Unlike the ovary, the male testis is about five centimeters long and up to three centimeters thick and wide. It is ovoid and located in the scrotum. It is suspended from the spermatic cord (funiculus spermaticus). It is externally sheathed by a serous skin, which corresponds to a peritoneal duplication and is anatomically analogous to the abdominal wall layers. The vegetative innervation of the male gonads is provided by the testicular plexus and the deferential plexus.
Function and Tasks
The gonads are glands. As such, they produce and secrete secretions with various tasks. In the human body, exocrine and endocrine secretions take place. Endocrine secretions include all secretions with hormonal functions. The function of the gonads is composed of exocrine and endocrine components. Exocrine they provide germ cells to the sexually mature individual, which correspond to oocytes in females and spermatozoa in males. With their exocrine functions, the gonads thus ensure the reproductive capacity and thus the continuation of the human species. Thanks to so-called spermatogenesis, the male may produce functional sperm cells until old age. Women finally complete oogenesis in the fifth month of development. Thus, they are not designed for endless production of eggs. The female maximum is about seven million germ cells, which pass into the dictyotene stage during embryogenesis and are stored there. At puberty, only about 400,000 of them are preserved. After the reproductive phase up to menopause, only about 500 germ cells still complete the follicular transition. In addition to the exocrine functions of germ cell production, the male and female gonads perform endocrine functions by providing the sex hormones estrogen and progestin as well as androgen. Both the exocrine and endocrine functions of the gonads can be eliminated by removing the gonads as part of castration.
Diseases
Intersexuality is an abnormality of the gonads. Genetically, intersexuals have a different sex than they do anatomically because of sex chromosomes. That is, their sex organs do not match their genetic sex. Hormonally, they cannot be clearly assigned to one of the two sexes.This intersexuality is also called sexual differentiation disorder and often corresponds to a congenital malformation, deformity and chromosomal abnormality. Usually, intersexuality results from an abnormal process during embryogenesis. The male gonads may also have congenital positional abnormalities. Such malpositions of the testes include, for example, pendulous testes, which are not permanently located in the scrotum but are flexible in their position. The female gonads can also be affected by congenital positional or shape anomalies, which, just like positional anomalies of the male testes, do not necessarily affect fertility. The gonads of both sexes are also a target for tumorous diseases. Cysts often occur on the ovary and ovarian tumors somewhat less frequently. On the testes, the equally rare testicular tumors are feared. More frequently, the gonads of both sexes are affected by hyper- or hypofunction. Inflammations of the gonads are also not uncommon, especially on the female ovaries. Ovarian inflammation usually arises from inflammatory processes in other pelvic organs in women and, depending on its severity, can cause fertility losses.
