The testes are the male sexual glands , also known as male gonads , and are present in the number two. The testicles do not always have the same volume over a lifetime. In the fetus they are located in the abdomen, and descend into the scrotum – the sack that encloses them – just before birth. In infancy they are small in size , and increase their volume during puberty, to reach the maximum size in the period of sexual maturity, and then regress physiologically in late age.
What are the testicles?
The testes are male sexual glands with an ovoid shape and firm consistency . At the end of sexual maturation, they reach a size of about 4-5 centimeters in length, 4 centimeters in width and 2-3 centimeters in thickness. They weigh about 20 grams each . Usually the left testicle is located lower than the right, even if the testicles are symmetrical.
Each testicle is internally separated into lobules (approximately 250 per testicle) which enclose the seminiferous tubules , within which the creation of spermatozoa occurs (spermiogenesis). The seminiferous tubules, initially convoluted (convoluted tubules), then take on a rectilinear shape (rectilinear tubules) and then converge within the testicular network (or “testis network”), composed of channels of different widths. Some ducts that reach the epididymis , a short elongated body on the posterior-upper end of the testicle that forms the tract of the spermatic pathways located between the efferent ducts of the testicular network and the vas deferens (conduit that deals with the transport of sperm), they originate from the testicular network.
Compact cell clusters that make up the interstitial gland of Leydig appear in the space located between the convoluted tubules. The spermatic plexus gives rise to the nerves that pass through the testicles. Finally, the blood vessels are called spermatic vessels .
What are the testicles for?
The testes perform an endocrine function and an exocrine function . The exocrine function originates from spermiogenesis , that is, from the creation of spermatozoa, indispensable for reproduction. This function is also possible in the presence of only one testicle.
The endocrine function is the secretion of testosterone : the existence of this hormone in the male body is fundamental, as well as for the induction of spermiogenesis, for the maturation of the so-called secondary sexual characteristics (growth of muscle mass, lowering of the timbre of the voice increase in hair on the body).
The exocrine and endocrine functions take place starting from puberty .