Functional Anatomy of Testes refers to the study of the anatomy of testes in relation to the functions of the primary sex organs called testes.
FUNCTIONAL ANATOMY OF TESTES
Testes are the primary sex organs or gonads in males. There are two testes in almost all the species. In human beings, both the testes are ovoid or walnut-bodies that are located and suspended in a sac-like structure called scrotum. Each testis weighs about 15 to 19g and measures about 5 × 3cm. Testis is made up of about 900 coiled tubules known as seminiferous tubules, which produce sperms. Seminiferous tubules continue as the vas efferens, which form the epididymis. It is continued as vas deferens.
COVERINGS OF TESTIS
Each testis is enclosed by three coverings.
- Tunica Vasculosa Tunica vasculosa is the innermost covering. It is made up of connective tissue and it is rich in blood vessels
- Tunica Albuginea Tunica albuginea is the middle covering. It is a dense f ibrous capsule
- Tunica Vaginalis Tunica vaginalis is the outermost closed cleft like covering, formed by mesothelial cells. It is formed by visceral and parietal layers, which glide on one another and allow free movement of testes. Visceral layer of tunica vaginalis adheres to tunica albuginea and the parietal layer lines the inner surface of the scrotum.
PARENCHYMA OF TESTIS
Lobules of Testis
Tunica albuginea on the posterior surface of testis is thickened to form the mediastinum testis. From this, the connective tissue septa called septula testis radiate into testis and bind with tunica albuginea at various points. Because of this, testis is divided into a number of pyramidal lobules, with bases directed towards the periphery and the apices towards the mediastinum.
Rete testis is a network of thin-walled channels present in mediastinum. All the seminiferous tubules open into the rete testis.
From rete testis, 8 to 15 tubules called vas efferens arise. Vas efferens join together and form the head of epididymis and then converge to form the duct of epididymis.