Male Genitalia Flashcards
Describe testes descent during development
Testes descend from the posterior abdominal wall towards the scrotum
Gubernaculum guides the testes down
Testes evaginate the abdominal wall - creates fascial layers that surround the testes
Where does spermatogenesis occur
Seminiferous tubules
Describe the route of sperm from the seminiferous tubule to the vas deferens
Sperm are released into lumen of seminiferous tubule
Sperm drain into straight tubule -> rete testis -> efferent ductules -> epididymis
Then pass through the epididymis into the vas deferens
What surrounds the seminiferous tubules
Tunica albuginea
What surrounds the testis and what is it formed by
Tunica vaginalis
Formed by the peritoneum during the testes descent
What cells are found in the testes, where are they found and what do they do
Sertoli - line seminiferous tubules. Support sperm maturation
Leydig - found in intersitium. Involved in sex hormone metabolism
What prevents testicles swapping sides
Scrotal septum
Describe the testicular blood supply
Testicular arteries come directly off the aorta
Testicular veins form pampiniform plexuses around testicular arteries
Left testicular vein drains into renal vein
Right testicular vein drains into IVC
Where do the testicular lymphatics drain and why is this important
Drain into the para-aortic lymph nodes
Important as metastases will be found here
Where do scrotal lymphatics drain
Inguinal lymph nodes
What are the three facial layers of the spermatic cord and what are they formed by
External spermatic fascia - external oblique muscle
Cremasteric fascia - internal oblique muscle
Internal spermatic fascia - transverse abdominis
What are the three arteries found in the spermatic cord
Testicular artery
Artery to vas deferens
Cremasteric artery
What are the three veins found in the spermatic cord
Pampiniform pleuxs
Vein to vas deferens
Cremasteric vein
What are the three nerves in the spermatic cord
Nerve to vas deferens
Cremasteric nerve
Ilioinguinal nerve
What is the cremasteric reflex
Reflex where if the inner thigh is stroked, the ipsilateral testicle will rise up towards the pelvis
What other three structures are found within the spermatic cord
Vas (ductus) deferens
Lymphatic drainage
Processus vaginalis/ patent processus vaginalis
What structures produce a substance that forms seminal fluid/sperm - include percentage
Epididymis and testes - 10%
Seminal vessels - 65%
Prostate gland - 25%
Bulbourethral glands - <1%
Describe the flow of seminal fluid from vas deferens to the urethra
Seminal fluid passes through vas deferens and combines with tubes and fluid from seminal vessels to form the ejaculatory duct
The duct then enters the central zone of the prostate where it flows into the urethra
Seminal fluid from the prostate is secreted into the duct here
Fluid then continues along the urethra to be ejected
What is found in fluid produced by the seminal vessels
Fructose-based alkaline fluid
What is found in fluid produced by the prostate
Milky secretion which is slightly acidic and contains proteolytic enzymes
What is the function of fluid produced by the bulbourethral glands
Decrease friction
How is the penis attached to the body
Corpus cavernosum attachs to pubic bones/pubic arch
Two suspensory ligaments support the penis at its base
What surrounds the corpus spongiosum and corpus cavernosum. What is its function
The tunica albuginea
It maintains the cylindrical shape during an erection - collagen fibres are arranged at right angles to each other
What is the blood supply to the penis
Pudendal arteries supply perineal arteries which then supply:
- Dorsal arteries
- Cavernous artery
- Bulbourethral artery
- Circumflex artery
What are the sections of the urethra
Prostatic urethra
Membranous urethra
Spongy urethra
How does an erection occur
Vasodilation of penile arterioles and compression of veins results in blood being pooled in the corpus cavernosum -> erection
