Describe the T.S. of human testis
Describe the histology of ‘human testis’.
Externally, each testis is covered by three layers. These are:
a. Tunica vaginalis:
It is the outermost incomplete peritoneal covering made up of connective tissue and
b. Tunica albuginea:
It is the middle layer formed by fibrous connective tissue.
c. Tunica vasculosa:
It is the innermost layer formed of delicate connective tissue, supporting a network of blood capillaries.
ii. Each testis contains about 200-300 tubules called seminiferous tubules.
iii. These are lined by a single layer of cuboidal germinal epithelium which undergo
iv. In the germinal epithelium, various stages of spermatogenesis such as spermatogonia,
primary spermatocytes, secondary spermatocytes, spermatids and sperms are seen.
v. Between these cells, few large and pyramidal cells called nurse cells or sertoli cells are
vi. Bundles of sperms are seen attached to Sertoli cells.
vii. These cells provide nourishment to the sperms till maturation.
viii. In between seminiferous tubules, connective tissue containing blood vessels, nerves, lymph vessels
and groups of interstitial cells (Cells of leydig) is present.
ix. Interstitial cells produce male hormone testosterone.
Histology of Testis : -
The testis is externally covered by fibrous connective tissue called Tunica albuginea. It is covered internally by Tunica vasculos which is formed by capillaries. Externally it is covered by the incomplete peritoneal covering called as Tunica vaginalis.
1) The Transverse section shows the presence of seminiferous tubules lined by cuboidal germinal epithelial cells. The germ cell undergoes the process of spermatogenesis
2) The transverse section also reveals different stages of spermatogenesis like spermatogonia, primary and secondary spermatocyte, spermatids and sperm.
3) Few large pyramidal cells present between germinal cells are known as Sertoli cells or Nurse cells. The function of Sertoli cells is to provide Nourishment of the sperm till maturation.
4) Between the seminiferous tubules, are the present cluster of polygonal cells known as Interstitial cells or Leydig cells. The Leydig cells secrete male sex hormone Testosterone or Androgen