Overview

The spermatic cord begins at the deep inguinal ring, lateral to the inferior epigastric vessels, traverses the inguinal canal, exits at the superficial inguinal ring and descends into the scrotum to the posterior border of the testis. Its coverings are acquired as the testis descends through the layers of the abdominal wall: internal spermatic fascia (from transversalis fascia), cremasteric muscle and fascia (from internal oblique) and external spermatic fascia (from the external oblique aponeurosis).

Its contents follow a "rule of threes": three arteries (testicular, cremasteric, artery to the ductus deferens), three veins (pampiniform plexus, cremasteric vein, vein of the ductus), three nerves (genital branch of the genitofemoral nerve supplying cremaster; sympathetic and visceral afferent fibres of the testicular plexus; the ilioinguinal nerve accompanies the cord in the canal but lies outside its coverings), and three other structures (ductus deferens, lymphatics, and the obliterated processus vaginalis).

The cremasteric reflex — stroking the superomedial thigh elevates the ipsilateral testis — has its afferent limb in the femoral branch of the genitofemoral nerve (and ilioinguinal) and its efferent limb in the genital branch of the genitofemoral nerve (L1–L2).

Location: From the deep inguinal ring through the inguinal canal and superficial ring to the posterior border of the testis.

Parts & subdivisions

Ductus deferens
Felt as a firm cord in the posterior part of the spermatic cord.
Testicular artery
From the abdominal aorta at ≈L2.
Pampiniform venous plexus
8–12 anastomosing veins that cool arterial blood (countercurrent heat exchange) and unite as the testicular vein.
Cremasteric artery and vein
From the inferior epigastric vessels; supply the coverings.
Genital branch of the genitofemoral nerve
Motor to cremaster (L1–L2); sensory to anterior scrotum.
Lymphatics and autonomic nerves
Testicular lymph to para-aortic nodes; sympathetic testicular plexus.
Processus vaginalis remnant
Fibrous vestige; if patent, allows an indirect inguinal hernia or communicating hydrocele.

Function

Suspends the testis.
Conveys the ductus deferens, blood supply, lymphatics and nerves of the testis.
Regulates testicular temperature (pampiniform plexus, cremaster).

Clinical significance

Varicocele

Varicose dilatation of the pampiniform plexus, ≈90 % left-sided; associated with subfertility and testicular atrophy; "bag of worms" that decompresses on lying down.

Indirect inguinal hernia

A hernia through a patent processus vaginalis travels within the spermatic cord coverings, emerging from the deep ring lateral to the inferior epigastric vessels; it may descend into the scrotum.

Testicular torsion

Rotation of the cord compromises venous and arterial flow; the cremasteric reflex is typically absent.

Mnemonics

Rule of threes

3 arteries, 3 veins, 3 nerves, 3 others and 3 coverings.

Test yourself

A 14-year-old boy has sudden severe left testicular pain for 2 hours. The testis lies high and horizontal and the cremasteric reflex is absent. What is the correct next step?

Antibiotics for epididymo-orchitis
Urgent surgical exploration
Elective ultrasound next week
Analgesia and observation

Answer: Urgent surgical exploration

This is testicular torsion until proven otherwise. Testicular salvage falls sharply after ≈6 hours, so exploration (detorsion and bilateral fixation) should not be delayed by imaging.