Male Reproductive Anatomy : Mnemonics

Penile Layers

1. Albuginea (tunica albuginea): Envelopes 3 corporal bodies (2 cavernosa and 1 spongiosum)

2. Buck’s fascia: Separates corpora cavernosa from corpus spongiosum; separates superficial and deep dorsal veins of the penis

  • Corpora cavernosa
    • Forward continuation of crura
  • Corpus spongiosum:
    • Continuation of bulb of penis
    • Encloses spongy/penile urethra
  • Suspensory ligament: attachment to pubic bone maintains penile position during erection

3. Colle’s fascia: Continuous with Scarpa’s fascia of abdomen and Dartos fascia of scrotum

  • Fundiform ligament: It springs from the lower part of the linea alba and splits into 2 lamellae, which enclose the proximal part of the body of penis and after that connect on its urethral aspect together with the septum of scrotum.

4. Dermis (skin)

penile layers
Bertolotto M, Serafini G, Savoca G, Liguori G, Calderan L, Gasparini C, Mucelli RP. Color Doppler US of the postoperative penis: anatomy and surgical complications. Radiographics. 2005 May-Jun;25(3):731-48. doi: 10.1148/rg.253045100. PMID: 15888622.

Nerve Supply of Penis

Sensory and Motor:

  1. Motor: Pudendal nerve (S2-S4)
  2. Sensory: Ilio-inguinal nerve, Dorsal nerve of penis

Autonomic innervation:

  1. Parasympathetic (muscle relaxation) via S2-S4: Pointing (erection)
  2. Sympathetic (muscle contraction) via T11-L2: Shooting (ejaculation)

Scrotum and Testis Layers

LayerDerived from anterior abdominal wall
1. SkinSkin
2. Dartos muscle/fasciaSuperficial fascia
3. External spermatic fasciaExternal oblique aponeurosis
4. Cremasteric muscle/fasciaInternal oblique
5. Internal spermatic fasciaTransversalis fascia
6. Tunica vaginalis (parietal and visceral)Peritoneum
7. Tunica albuginea – septates testis into lobules

Since the testes are originally retroperitoneal organs, the lymphatic drainage is to the lumbar and para-aortic nodes, along the lumbar vertebrae. This is in contrast to the scrotum, which drains into the nearby superficial inguinal nodes.

Carcinomas confined to testes thus never result in inguinal lymphadenopathy and are surgically removed via and inguinal incision.

Male Urethra

PortionSegmentLengthFeatures
1. Posterior (lined by transitional columnar epithelium)Prostatic3 cmWidest and most dilatable
– Iliac lymph nodesMembranous2 cmShortest, narrowest and least dilatable
– Injury = Deep extravasation of urine (extraperitoneal/into deep perineal pouch)
2. Anterior (lined by pseudostratified columnar epithelium; distal-most portion by squamous epithelium)Bulbar
– Inguinal lymph nodesPenile/Spongy16 cmLongest
– Injury = Superficial extravasation of urine (intraperitoneal/into superficial perineal pouch)
urine extravasation

Spermatic Cord

Sperm Ejaculation Pathway

  1. Seminiferous tubules
  2. Epididymis
  3. Vas deferens
  4. Ejaculatory ducts
  5. None
  6. Urethra
  7. Penis

Derivatives of Embryonic Genital Structures

genital structure development
Embryonic structureMaleFemale
Indifferent gonadTestisOvary
CortexOvarian follicles
MedullaSeminiferous tubules
Rete testis
Medulla
Rete ovarii
GubernaculumGubernaculum testisOvarian ligament
Round ligament of uterus
Mesonephric tubulesDuctuli effernetis
Paradidymis
Abberant ductules
Ductus epididymis
Ductus deferens
Ureter, pelvis, calyces and collecting systems
Epoophoron
Paraoophoron
Duct of epoophoron
Duct of paraophoron
Ureter, pelvis, calyces and collecting systems
Mesonephric ductAppendix of epididymis
Ejaculatory duct & seminal vesicle
Paramesonephric ductAppendix of testis
Prostatic utricle
Hydatid of Morgagni
Fallopian tubes
Uterus
Vagina (upper)
Genital tuberclePenisVestibule
Clitoris
Urogenital foldsVentral (under) aspect of penis – penile urethraLabia minora
Labioscrotal swellingsScrotumLabia majora


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