The Histology Guide

Male Reproductive system: Testis

diagram of testis

The pair of testes produces spermatozoa and androgens. Several accessory glands produce the fluid constituents of semen. Long ducts store the sperm and transport them to the penis.

The male reproductive system consists of paired testes and genital ducts, accessory sex glands and the penis. The testes and ducts are shown in this diagram.

Testis organisation.

This low power photograph of the testis shows its basic organisation.

Can you identify - the thick collagenous capsule on the outside called the tunica albuginea. Can you also identify the seminiferous tubules, which open into a network of anastomosing channels called the rete (rete = net) testis at the mediastinum testes.

The spermatozoa are made in the semiferous tubules of the testes. Find out more in the Spermatogenesis topic

Septa which emanate from this capsule to subdivide the testis into about 250 incomplete lobules. The septa converge towards the midline of the posterior border, meeting along a thickening of the tunica albuginea called the mediastinum testis.

Each lobule contains one to four seminiferous tubules embedded in a connective tissue stroma. Each of the seminiferous tubules are 30-70 cm long.

Formation of sperm is supported by Sertoli cells, and Leydig cells. Click here to find out about these cells.

Tunica albuginea

This image shows a magnified image of the tunica albuginea, the thick fibromuscular connective tissue capsule of the testis - can you identify it?

questionWhat is it made of?

The inner vascular layer is the tunica vasculosa.

questionNow take a look at this section of a diseased testis - how does it appearance differ from that of the normal testis - how might this be explained?