Male Reproductive Anatomy Flashcards
(47 cards)
How do the testes develop?
From intermediate mesoderm high on posterior abdominal wall in retroperitoneal position dragging the neurovascular supply and lymph vessels with it as they descend through inguinal canal along the gubernaculum to scrotum and anterior abdominal wall layers end up surrounding them and the spermatic cord - outpouching of parietal peritoneum forms the processus vaginalis which later forms the tunica vaginalis
What is the site of spermatogenesis?
Seminiferous tubules of the lobules of the testes in the scrotum
What is the lymph drainage of the testes?
Para-aortic lymph nodes (}L2)
What can be the consequence of a patent processus vaginalis?
Potential weak spot for indirect inguinal hernias
What is the scrotum?
A loose pouch of thin skin with layers derived from abdominal wall that testes lie within functioning to keep the testes at 3-4 degrees cooler than body temp. via altering their proximity to the body
What is the structure of the testes?
- Surrounded by tunica vaginalis that contain a visceral and parietal layer with small amount of fluid in between
- Tough fibrous coat called tunica albuginea gives rise to septa and divides into lobules
- Lobules contain seminiferous tubules which connect to rete testis, then to epididymis via efferent ductules (route of spermatozoa)
What is a hydrocele? How do you examine it?
Excessive fluid in the tunica vaginalis caused by inflammation, infection, developmental issues, trauma, neoplasm etc. - diagnose by transillumination ability
What is the epididymis?
Structure situated posteriorly and superiorly of testes with a head, body and tail:
- Head receives numerous efferent ductules
- Tail connects to ductus deferens (site of maturation and storage of spermatozoa) so sperm can move to the urethra to be ejaculated
What is a cause of epididymo-orchitis?
STIs
How can you clinically distinguish between hydrocele, spermatocele and testicular cancer?
Hydrocele: testes cannot be felt as the swelling covers the testes
Spermatocele/epididymal cyst: testes CAN be felt and inflamed epididymis will be felt superiorly (slightly posterior) of testes
Testicular cancer: multiple hard lumps can be felt within the testicle itself
What are the contents and coverings of the spermatic cord?
Rule of 3s:
- 3 x coverings/layers = internal spermatic fascia, cremasteric fascia + external spermatic fascia
- 3 x arteries = testicular, cremasteric + ductus deferens
- 3 x nerves = genital br. of genitofemoral, autonomics + illioinguinal
- 3 x other structures = ductus deferens, pampiniform plexus + lymphatics
What is the cremasteric reflex?
If you stroke and stimulate the anterior medial thigh, the muscular cremasteric fascia contacts and brings up the testicles
What are the layers of the spermatic cord derived from?
Internal spermatic fascia = transversalis fascia
Cremasteric fascia = internal oblique
External spermatic fascia = external oblique aponeurosis
Where can testicular pain refer to?
Abdomen
What is special about the vasculature of the testes?
Testicular arteries originate from aorta and pampiniform plexus from the testicular veins wrapped around testicular artery forming an arrangement that allows a counter-current heat exchange mechanism
What is the venous drainage of the testes?
R: testicular vein > IVC
L: testicular vein -> renal vein > IVC
(Similar to ovarian drainage)
What disorders occur of testicular vasculature?
Torsion (arterial): twisting of testis resulting in compromised blood supply - MEDICAL EMERGENCY
Varicocoeles (venous) most common on the L: abnormal dilations of pampiniform plexus
What is a vasectomy?
Male sterilisation performed by cutting and ligating (or cauterising) ductus vas deferens via a scrotal incision
What are the ductus vas deferens?
Muscular smooth muscle tube derived capable of peristaltic action via sympathetic innervation running from the tail of the epididymis to the ejaculatory duct (superior to ureter in pelvic cavity) which also meets the seminal vesicles at the widened ampulla - blood supply from local vessels on its course
What are seminal vesicles?
Paired accessory sex glands located behind the bladder and related posteriorly to rectovesical pouch (palpable in some people) that produce alkaline fluid to contribute to seminal fluid uniting with the ductus deferens to form the ejaculatory ducts which open into prostatic urethra raised central area called the seminal colliculus/veramontanum (useful landmark during TURP)
What is the prostate gland?
1/3 fibromuscular and 2/3 glandular tissue superior to perineal membrane between the bladder and levator ani surrounding the urethra (prostatic urethra/urethral crest) contributing volume to the seminal fluid via openings within prostatic sinus - blood supply from ILA branches vesical and rectal a.’s
How can you examine the prostate?
Lies directly anterior to lower rectum so posterior aspect is palpable via DRE
What sympathetically innervated structure prevents retrograde ejaculation?
Internal Urethral Sphincter (IUS)
What are the lobes and zones of the prostate?
Lobes based on positional relationship of prostate tissue to urethra and ejaculatory duct:
- Anterior
- Median - BPE
- Posterior
Zones from closest to furthest from urethra:
- Transitional (TZ) - BPE
- Central (CZ)
- Peripheral (PZ) - cancer