Testicular anatomy

Question 1

What is contained in the spermatic cord?

Answer 1

1. Arterial (3):
•	Testicular artery
•	Cremasteric artery
•	Ductus deferens artery
2. Innervation (3):
•	Genital branch of genitofemoral nerve
•	Testicular sympathetic nerve
•	Illioingunal nerve (not within spermatic cord but runs along side)
3. Venous: pampiniform plexus
4. Lymphatic vessels 
•	Testicle -> para-aortic LNs
5. Ductus deferens

Question 2

What are the layers of the scrotum?

What are they derived from?

Answer 2

Scrotum layers:
(“Some Damn Englishmen Call It The Testes”)
• Skin
• Dartos fascia and muscle- derived from superficial fascia (Camper’s and Scarpa’s)
• External spermatic fascia- derived from external oblique muscle and fascia
• Cremasteric muscle and fascia- derived from internal oblique muscle and fascia
• Internal spermatic fascia- derived from transverse fascia
• Tunica vaginalis- derived from parietal peritoneum
• Tunica albuginea- fibrous CT covering testis

Question 3

Describe the innervation of the testes?

Answer 3

o Aortic plexus -> renal plexus -> spermatic plexus (main supplier of testes)
o Genital branch of genitofemoral nerve: lumbar plexus (L1-2) -> inguinal canal -> genitofemoral nerve (genital branch) -> supplies scrotal skin, cremasteric muscle, tunica dartos
o Illioinguinal nerve: lumbar plexus -> ilioingional nerve -> scrotal skin, penis, groin, medial thigh

Question 4

Describe the embryological development of the testes?

Answer 4

• Testes originate from mesonephric duct and medullary sex cords
• 7 weeks: organised into primitive testes structure (T10)
- Gubernaculum has superior attachment to testes and inferior attachment to genital swelling
• 3 months: descent of testes
- Gubernaculum shortens -> testes travels from intra-abdominal area -> inguinal canal
- Processus vaginalis develops (invagination of parietal peritoneum) -> travels with testes through inguinal canal
- Testes descend -> pulls along layers of abdo wall
• 9 months - birth: testes travel in inguinal canal to scrotum
• 1st year of life: obliteration of upper part of processus vaginalis (failure -> risk hydrocele and indirect inguinal hernia)