The Male Genital Organs – an Overview Male genitals The Male Genital Organs – an Overview Per Brodal Institutt for medisinske basalfag Universitetet i Oslo 9th Semester 2008

Overview Vesicula seminalis (glandula vesiculosa) Ductus deferens Male genitals Overview Vesicula seminalis (glandula vesiculosa) Ductus deferens Prostatic gland Urethra Part of the pelvic floor (diaphragma urogenitale) Penis Glandula bulbourethrales Epididymis Testis P. Brodal 2008

Descent of the Testes during Development Male genitals Descent of the Testes during Development Peritoneum Testis Scrotum Left figure: 7 cm crown-rump length Mention gubernaculum, leading the direction When the testes arrive normally in the scrotum; by 7th month at the entrance to the inguinal canal Temperature in scrotum (certain animals have intrabdominal testes Point to the processus vaginalis, but perhaps not the name Explain the origin of indirect hernia Hydrocele Accoerding to Benninghoff is the right processus vaginalis obliterated later than the left – this is said to explain the higher frequency of right-sided indirect hernia Retentio testis (kryptorchismus): When the testes do not reach the scrotum The testes develop on the posterior abdominal wall Processus vaginalis Tunica vaginalis P. Brodal 2008

The Layers of the Scrotum: Derived from the Abdominal Wall Male genitals The Layers of the Scrotum: Derived from the Abdominal Wall Peritoneum Transverse fascia Internal oblique muscle The scrotum is designed for temperature-control Cremaster muscle (striated) Fascia spermatica interna Ductus deferens Skin (fat-free) Scrotum is a temperature-regulating organ The scrotal skin: no fat Tunica Dartos: smooth muscle layer, especially reactive to change of temperature: relaxation by heating, by contraction is heat loss reduced Continues into the spematic cord Temperature 2,5-4 degrees lower than intraabdominally; (mention that testes are intraabdominal in some mammals – eg. Elephant, whales, also in birds) Functional significance of the layers of the scrotum, with an elaborate system of striated and smooth muscles: Tunica Dartos (smooth muscles) Testis Tunica vaginalis P. Brodal 2008

Scrotum and the Spermatic Cord Male genitals Scrotum and the Spermatic Cord Tunica vaginalis (parietal layer) Cremaster muscle Fascia spermatica interna Epididymis Point to vessels and nerves in the funiciulus Testis P. Brodal 2008

The Spermatic Cord (Funiculus spermaticus) Male genitals The Spermatic Cord (Funiculus spermaticus) Plexus pampiniformis Cremaster muscle Ductus deferens Arteria testicularis Arteria testicularis Ductus deferens Point to the anulus inguinalis superficialis Plexus pampiniformis P. Brodal 2008

The Inguinal Canal Transversus abdominis muscle Male genitals The Inguinal Canal Transversus abdominis muscle External oblique muscle Internal oblique muscle Inguinal (indirect) hernia To illustrate both how the funculus pierces the abdominal wall, and the origin of the ceremaster muscle from the internal obliqu muscle Anulus inguinalis superficialis Spermatic cord Anulus inguinalis profundus Thieme, Atlas of Human Anatomy 2006 P. Brodal 2008

Testis and Epididymis Tunica albuginea Caput epididymidis Male genitals Testis and Epididymis Tunica albuginea Caput epididymidis Ductus epididymidis (6 m) Tunica albuginea (connective tissue, indistensible after puberty, cf effect of mumps in postpubertal males) Testis. Connective tissue ”septula”, incompletely separates lobuli.’ Each testis lobulus has several convoluted tubuli seminiferi, 30 – 80 cm long) Altogether probably about 300 m * Each epididymis consists of one 6 m long ductus epididymidis. Note spelling and pronounciation of epidydimis, ductus epididymidis. Ductus deferens P. Brodal 2008

The Prostatic gland Peripheral glands Inner glands Urethra Male genitals The Prostatic gland Peripheral glands Inner glands Urethra Colliculus seminalis The prostatic about 4 cm in Inner = periurethral (hypertrophy common) Outer = main (cancer common) P. Brodal 2008

The Male Urethra and Associated Glands Male genitals The Male Urethra and Associated Glands Prostatic gland Vesicula seminalis Colliculus seminalis Pars prostatica Pars membranacea Pars spongiosa Bulbourethral glands P. Brodal 2008 Ductus ejaculatorius

The bladder and prostatic gland from behind Male genitals Glands Ampulla of ductus deferens Colliculus seminalis Vesicula seminalis Urogenital diaphragm Prostata bulbo-urethral glands Openings of ducts from bulbo-urethral glands The bladder and prostatic gland from behind Netter P. Brodal 2008

Penis Glans penis Corpora cavernosa Corpus spongiosum Male genitals Penis Glans penis Corpora cavernosa Corpus spongiosum Ischiocavernosus muscle Urethra Corona glandis Fossa navicularis Bulbus penis P. Brodal 2008 Bulbospongiosus muscle

Mechanism of Erection – Corpora cavernosa Male genitals Mechanism of Erection – Corpora cavernosa Squeezing of veins Tunica albuginea Arterial dilatation Opening of helicine arteries; relaxation of smooth muscle in wall of the caverns- more questionable whether squeezing of veins contribute Blood-filled caverns P. Brodal 2008

Arteries of the pelvis Common iliac artery (a. iliaca communis) Male genitals Arteries of the pelvis Common iliac artery (a. iliaca communis) Superior and inferior gluteal arteries Internal iliac artery (a. iliaca interna) External iliac artery (a. iliaca externa) Internal pudendal artery (a. pudenda interna) Obturator artery (a. obturatoria) Superior vesical artery Middle rectal artery (Uterine) P. Brodal 2008

Arterial supply of the pelvis Male genitals Arterial supply of the pelvis P. Brodal 2008

Variations: Branching of internal iliac artery Male genitals Variations: Branching of internal iliac artery Internal iliac Internal pudendal Inferior gluteal P. Brodal 2008

Blood Supply of the Testis Male genitals Blood Supply of the Testis Testicular artery Venous drainage P. Brodal 2008

Blood Supply of the Penis Male genitals Blood Supply of the Penis Internal pudendal artery Dorsal artery Deep arteries P. Brodal 2008

Lymphatic Drainage of the Testes and Scrotum Male genitals Lymphatic Drainage of the Testes and Scrotum Lumbar lymph nodes Superficial inguinal lymph nodes P. Brodal 2008

Scrotal Swelling – What can it be? Male genitals Scrotal Swelling – What can it be? Inguinal hernia Hydrocele Spermatocele Bimanual examination Varicocele Epididymitis Testicular tumor Spermatocele: retention cyst in the epididymis Varicocele: painful varicose dilatations of the pampiniform plexus Epididymitis: painful bacterial infection of the epididymis Testicular tumor: painless, usually unilateral induration of the testis Is the mass confined to scrotum? Is there a transient elnlargement when the patients coughs? Is the mass translucent when examined with transillumination? Thieme Atlas of Anatomy Is the mass confined to the scrotum? Is there a transient enlargement when the patients coughs? Is the mass translucent? P. Brodal 2008