Testes are male gonads.
They are reproductive and endocrine organs responsible to produce sperm and testosterone respectively. They are suspended in the scrotum.
Each testis has 3 intrinsic coverings ( from outside to inside )
- TUNICA VAGINALIS
- TUNICA ALBUGINEA
- TUNICA VASCULOSA
TUNICA VAGINALIS is the peritoneal or serous sac ( it is the lower end of the peritoneal processus vaginalis ).
It has 2 layers
- Parietal layer
- Visceral layer
Between the 2 layers there is a cavity called as the cavity of tunica vaginalis.
The cavity always contains a thin film of fluid, which can occasionally increase to form hydrocele.
TUNICA ALBUGINEA is thick fibrous layer composed of interlacing bundles of collagen fibres, bluish white in appearance.
At the posterior border of the testis it is thickened to form MEDIASTINUM TESTIS.
Mediastinum testis gives rise to thin incomplete fibrous septas dividing the testis into TESTICULAR LOBULES, around 200 to 300 in number.
Each testicular lobule contains 1 to 4 seminiferous tubules. Sperm production occurs within the seminiferous tubules. Seminiferous tubules are lined with a stratified epithelium called as GERMINAL EPITHELIUM. There are 2 types of cells in the germinal epithelium..
- Spermatogenic cells (they produce sperm)
- Sertoli cells (they nourish the developing sperm)
Seminiferous tubules continue as STRAIGHT TUBULES in the mediastinum testis. Straight tubules do not contain spermatogenic cells and are lined with cuboidal or low columnar epithelium. Straight tubules continue into a network known as RETE TESTIS.
10 TO 15 EFFERENT DUCTULES or VAS EFFERENTIA arise from the rete testis, highly coil to form EPIDIDYMIS (Head , Body and Tail ).
Tail of the epididymis continues as VAS DEFERENS.
Formation of sperm known as SPERMATOGENESIS takes place inside the seminiferous tubules.
So the pathway of sperm is...
- RETE TESTIS
- EFFERENT DUCTULES
- VAS DEFERENS
- EJACULATORY DUCT