Synonyms
Lat. = Testis (Pl. Testes)
Definition
The paired testicles (Testis) belong together with the epididymis, the spermatic duct and the male sex glands (vesicle gland and prostate) to the internal male sex organs. They serve the production of sperm cells (sperm) and are located below the male member. Each testicle is “suspended” from the spermatic cord and lies loosely in the scrotum surrounding it. They serve as gonads for the production of sperm and hormones, which is regulated by the hypothalamus and pituitary gland.
Function of the testicles
The testicles serve on the one hand for the production of hormones, the androgens, and on the other hand for the production of sperm for reproduction. Responsible for the synthesis of hormones are the Leydig cells, which mainly produce testosterone. Testosterone is important on the one hand for stimulating the formation of sperm, and on the other hand for the development and maintenance of the function of the other sexual organs.
The development of sperm is mainly enabled and supported by the Sertoli cells. They form a supporting framework of cells in which the sperm mature from the germ cells. The epididymis acts as a storage for the sperm. They also serve to mature their function.
Development of the testicles
In the course of embryonic development, the testicle (testis) moves from the abdominal cavity through the inguinal canal to its definitive place in the scrotum. The reason for the displaced position of the testis is the lower temperature there, which is necessary for the development of the testis as well as for sperm production. Responsible for the development of the testicles is the testis-determining factor (TDF) on the Y-chromosome, which only men possess.
This causes the preliminary stages, the still indifferent gonads, to develop into the definitive testis. The female reproductive organs are reduced by the anti-Müller hormone (AMH). This hormone is produced by special cells of the testis, the Sertoli cells.
The cells in the testicular system, the Leydig cells, begin to produce the hormone testosterone in the 8th week of embryonic development, which causes the development of the male genitals. The testicles (testis) are located outside the abdominal cavity in the scrotum. At the back, inside the scrotum, there is an epididymis.
The testicles have an elongated, oval shape with a diameter of 3cm and a length of 4cm. In the testis a system of different tubules (lat. = tubules) and ducts (lat. = ductus) begins, which leave the organ at the mediastinum, a centrally located pole, and end in the epididymal duct, the Ductus epididymidis. This continues as the Ductus deferens, then moves through the inguinal canal into the abdominal cavity and connects to the urethra via the short Ductus ejaculatoius.
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