Testis

Function

Each testis is a sperm factory and endocrine organ in one: 250 m of seminiferous tubules packed into 4 cm, producing 1,500 sperm per second from puberty onward, while its Leydig cells secrete the testosterone that masculinised the body and maintains it.

Spermatogenesis runs 74 days at a temperature 2–3 °C below core — the reason the testes migrated into the scrotum's external pouch, suspended by the spermatic cord's supply lines. The left testis hangs lower in most men, its vein draining to the left renal vein at a right angle.

Blood supply

Testicular artery from the aorta (the long route of its embryological descent); pampiniform plexus drains to the gonadal vein.

Nerve supply

T10–L1 sympathetic fibres (testicular pain refers to the abdomen); genital branch of the genitofemoral nerve to the scrotal skin.

Clinical relevance

Testicular torsion

The cord twists in the adolescent bell-clapper deformity — 6 hours separate salvage from loss; sudden testicular pain is a surgical emergency.

Testicular cancer

The young man's cancer — a painless lump; teratomas and seminomas are among the most curable malignancies.

Varicocele

Left-sided venous incompetence bags the scrotum — the commonest reversible cause of male subfertility.

Related conditions

• Testicular cancer
• Testicular torsion
• Male infertility