Scrotum A&P

• Anatomy Of the Scrotum

  • Fibromuscular pouch continuous with the skin of the lower abdomen
  • Located between the penis and anus
  • Hangs outside of the body
  • To lower the temperature of the testes to promote sperm production
• Scrotal wall

  • Thin layer of skin
  • Normal thickness 2-8mm (can indicate infections)
• Layers of the scrotal wall(outer to inner)

  1. Skin

  2. Dartos muscle

  3. External spermatic facia

  4. Cremaster muscles

  5. Internal spermatic facia

  6. Parietal layer of TUNICA VAGINALIS
• Anatomy of the scrotum

  • Divided into two compartments, separated by RAPHE
  • PERINEAL RAPHE - externally
  • MEDIAN RAPHE - internally
• Anatomy of the Scrotum

  • Testicle
  • Epididymis
  • Blood vessels
  • Spermatic cord
  • Fluid
• Anatomy of the Scrotum

  • Small bare area, which is posterior
  • At this site, testicle is against scrotal wall, preventing torsion
  • Blood vessels, lymphatics, nerves, spermatic ducts travel through area
  • HYDROCELES (cystic fluid collection) form in space between layers of tunica vaginalis
• Testes

  • Formed in the abdominal cavity and descend through inguinal canal into scrotum
  • Typically 7th gestational month
  • Symmetrical ovoid shaped
  • Adults measure: 3-5cm length, 2-4cm in TRV, 3cm in A/P
• Testes

  • Suspended in scrotum by SPERMATIC CORD
  • Inferiorly testes anchored by GUBERNACULUM TESTIS (Scrotal ligament)
  • Each teste – more than 250-400 conical lobules containing seminiferous tubules
  • Tubules converge at apex of each lobule
  • Anastamose to form RETE TESTIS in mediastinum
• Testes

  • RETE TESTIS – network of ducts that drain into head of EPIDIDYMIS through EFFERENT DUCTULES
  • The rete testis is a network of epithelial-lined channels embedded within the fibrous stroma of the mediastinum testis
• Testes

  • Completely covered by tunica albuginea, a dense fibrous tissue
  • Tunica vaginalis lines the inner walls, covering each testis & epididymis
  • Parietal
  • Visceral
  • Mediastinum testis courses craniocaudad within testis
  • Production of testes is testosterone and sperm
• Epididymis


  • 6-7cm tubular structure
  • Begins superiorly and the courses posterolaterally to testicle
  • Divided: Head (largest part, 6-15mm in width, located at superior to upper pole), Body (smaller, posterolateral aspect of testis), Tail (slightly larger, posterior to lower pole)
• Epididymis

  • 10-15 efferent ductules from rete testis
  • Converge to form single duct in body and tail
  • DUCTUS EPIDIDYMIS
  • Becomes VAS DEFERENS and continues in spermatic cord
  • Conduit for sperm originating in testis and expressed via the seminal vesicles
• Appendix of Epididymis – small protrusion from head of Epi
• Vas deferens

  • Continuation of ductus epididymis
  • Dilates at terminal portion near seminal vesicles
  • Joins seminal vesicles to form ejaculatory duct
  • Ejaculatory duct meets with urethra at the VERUMONTANUM
  • Urethra courses from bladder to end of penis
  • In men urethra transports both urine and semen to outside of body
• Mediastinum

  • Multiple septa (SEPTA TESTIS) - Formed from tunica albuginea at mediastinum
  • These septa course through testis and separate it into lobules
  • Mediastinum supports vessels and ducts coursing within testis
  • Mediastinum often seen on sonography as bright hyperechoic line coursing craniocaudad within testis
• Right and left testicular arteries arise from abdominal aorta below level of renal arteries.
• Vascular supply


  1. Capsular arteries give rise to centripetal arteries, which course from testicular surface toward mediastinum along septa

  2. Before reaching the mediastinum, they curve backward forming recurrent rami (centrifugal arteries)

  3. Branch further into arterioles and capillaries
• Vascular supply

  • Cremasteric and deferential arteries accompany testicular artery within spermatic cord to supply extratesticular structures
  • Have anastomoses with testicular artery and may provide some flow to testis
  • Cremasteric artery branches from inferior epigastric artery (branch of external iliac artery)
  • Provides flow to cremaster muscle and peritesticular tissue
• Vascular supply

  • Venous drainage of the scrotum occurs through veins of PAMPINIFORM PLEXUS
  • Pampiniform plexus exits from mediastinum testis and courses in spermatic cord
• PAMPINIFORM PLEXUS (pp)

  • Testicular
  • Deferential
  • Cremasteric
• Vascular supply

  • Right testicular vein drains into inferior vena cava; left testicular vein joins left renal vein
  • Deferential vein drains into pelvic veins; cremasteric vein drains into tributaries of epigastric and deep pudendal veins