Clinical anatomy of male repro tract Flashcards
Define the following terms:
a) spermatocele
b) Hydroceoele
c) Haemotocoele
a) benign growth filled with clear liquid found at the head of the epididymis
b) serous fluid in the tunica vaginalis
c) Blood within the scrotal sac but outside the testis
Describe how the testis attains somatic fascia and a tunica vaginalis
The testicle originally develops in a retroperitoneal position, as the testis descends and follows the gubernaculum through the three layers of peritoneum each attains 3 CT coverings!
First, the testis pushes through processes vaginalis (a fold of parietal peritoneum), and the lower part of the processes form the tunica vaginalis
What is an inguinal hernia? Describe the two types, how they form and which is more common.
Inguinal hernia: tissue (such as intestines) protrudes through a weak spot in the abdominal muscles, the resulting bulge can be very painful.
- Indirect: More common, the processus vaginalis is a weak area, if it fails to close some coils of the intestine can follow it down with the testis pushing through the deep inguinal ring and causing a lump.
- Direct: bulging of the peritoneal cavity, often caused by age-related stress and weakened muscles in the inguinal canal
What are the three central contents of the spermatic cord?
- Pampiniform plexus; drains venous blood from testis to testicular vein, it wraps around the testicular artery and acts as a heat exchanger to cool the arterial blood before it reaches the testis
- Ductus deferens
- Lymphatics
What are the three arteries in the spermatic cord?
- Testicular artery: from AA, L2
- Ductus deferens artery
- Cremasteric artery; supplies cremasteric fascia and muscle
What are the three major nerves in the spermatic cord?
- Genital branch of the genitofemoral nerve/external spermatic nerve
- Autonomic nerves
- Ilioinguinal nerves
List the three fascias surrounding the spermatic cord in medial-lateral order, where do they arise from?
They are derived from the three layers of anterolateral abdominal wall muscles and collect around the testis as they push down
- Internal spermatic fascia; (innermost layer the testis push through), derived from the lining of transversus abdominis muscle
- Cremasteric fascia; derived from internal oblique muscle
- External spermatic fascia; derived from external oblique muscle
What does the Genitofemoral nerve innervate?
Gives off two divisions:
- Femoral: gives sensory innervation to the upper medial thigh
- Genital: supplies cremaster muscle around the testis
What is the cremasteric reflex?
When you stimulate the upper medial thigh the testis should rise!!!!!!!!!
Describe the anatomical course of the spermatic cord
- Formed in the opening of the inguinal canal
- Enters scrotum via superficial inguinal ring (terminal end of the inguinal canal)
- Ends at the posterior border of the testis; its contents then disperse to supply the testis and the scrotum
What is a varicocele and why does it form?
A lump in the scrotum due to incompetent valves in the pampiniform plexus
What is torsion?
When the testicle rotates and twists the spermatic cord, reducing the bloodflow to the testis and causing sudden and severe pain/swelling
Which branch of the autonomic NS allows for peristalsis in the ductus deferens?
Sympathetic
What are the ductus deferens derived from? What is their anatomical location and what is meant by the term ‘water under the bridge’? What is their blood supply?
Derived from the embryonic mesonephric duct;
Runs from the tail of the epididymis to the ejaculatory duct, it is the ONLY structure that passes superiorly to the ureter (hence, water under the bridge)
Supplied by branches from the vesicular and testicular arteries
Which two structures form the ejaculatory duct?
The convergence of the ductus deferens and the seminal vesicle duct
What is a vasectomy? Is it reversible?
When the ductus deferens is cut distal to the superficial inguinal ring, occasionally the cut ends can find each other and rejoin :’)
What are the two main components of the prostate?
1/3 Fibromuscular: contracts during ejaculation to squeeze out the fluid in the glandular tissue
2/3 Glandular: produces 20% of seminal fluid
What supplies and drains the prostate? (including which lymphatic nodes)
Supply: Internal iliac artery (vesical and rectal arteries)
Drain: venous blood goes into the prostatic venous plexus which communicates with the vertebral veins… Lymph drains into the internal iliac nodes
What are the zones of the prostate? Which zone are tumours usually in? Which zone becomes bigger with age, what does this cause and what is this known as?
Central zone: surrounds the prostatic urethra
Peripheral zone: usually the zone with tumours
Transitional zone: Where prostatic hyperplasia tends to occur and can cause a degree of incontinence
Where does prostate cancer commonly spread to and why?
Spreads to the vertebrae via the venous plexus as valveless veins form the plexus (so blood can flow freely in either direction)
What is the role of the seminal vesicles and where do they arise from?
They produce alkaline fluid (70-80% of ejaculate volume) and they develop as outgrowths of the ductus deferens between the bladder and the rectum
What is the blood supply and drainage (including lymphatics) for the seminal vesicles?
Blood supply: internal iliac artery (inferior rectal and middle rectal)
Vesical and prostatic venous plexus
Internal iliac, external iliac and sacral nodes
What does the perineal membrane do?
Act as an anchoring point for external genitalia (somewhat forms the boundary between the prostatic and membranous urethra)
Name four points on the journey of a male catheter where passage might be more difficult
- Navicular fossa; superior mucosal fold (right before external urethral orifice)
- The angle at the penile bulb and membranous urethra
- Prostate (crest/enlarged lobes)
- Sphincters (internal and external)
Name four things you should be able to feel in a DR examination and two things you might feel (that would still be physiological)
- Walls of the anal canal
- Walls of the inferior rectum
- Lymph nodes; coccyx and sacral/sacrum
- Prostate (posterior and median lobes)
Two maybes: inferior bladder, seminal vesicles
What are the three vascular structures of the penis
- Corpus spongiosum; has urethra and expands distally to form ‘glans penis’
- 2X corpus cavernosum; erectile tissue filled with blood vessels
- Bulb of the penis (roots the corpus spongiosum and is in the midline of the penile root) is also an erectile tissue
What is contained in the superficial perineal pouch?
Penis, urethra, scrotal contents and superficial perineal muscles
What can you do if you wanted to give your penis a greater flaccid length?
Cut the fundiform and suspensory ligaments of course!
How does neurovasculature reach the penis?
Pudendal nerve: Travels inferior to the pelvic floor via the deep perineal pouch and through the pudendal/Alcock’s canal
Where on its journey can the pudendal nerve be anesthetized?
When it passes close to the ischial spine (after exiting the greater sciatic foramen)
What supplies and drains the penis?
Arterial: Three arteries that all branch from the internal iliac -> internal pudendal artery: deep and dorsal penile arteries, and the bulbourethral artery
Dorsal veins: drain into prostatic venous plexus -> vertebral plexus
- Superficial dorsal vein: skin and cutaneous tissue
- Deep dorsal vein: cavernous spaces
Describe the vascular component of an erection (including which muscles are involved in the vascular component)
In an erection, the coiled helicine arteries straighten to allow blood to fill the corpus cavernosum
- Erotic stimuli: relaxes the smooth muscle surrounding the helicine arteries so the vessels can straighten
- The arterial-venous anastomoses close to retain blood in the corpus cavernosum
- Ischiocavernosum and bulbospongiosum also compress the venous plexus and retain blood in the penis
Describe the nervous component (not vascular component) of an erection, how do the nerves reach the penis?
Nerves lie on lateral pelvic wall and then travel medially to form a plexus around the prostate
Parasympathetic S2-4: allows for an erection
-Pelvic splanchnic nerves -> inferior hypogastric plexus -> prostatic plexus -> cavernous nerve
Where is the deep perineal pouch? What kind of structures are in it (for females and males) and what innervates it?
It sits between the pelvic floor and the perineal membrane; Voluntary muscles
Male: external urethral sphincter, bulbourethral glands
Female: multiple sphincters
Innervated by the pudendal nerve
Name two things that can exacerbate the pain of having an infection or stones in the male bulbourethral gland
DR examination and defecation
Where does the crura of the penis/clitoris attach to?
The pubic arch and the lateral parts of the perineal membrane
What is priapism?
Persistent painful non-stimulated erection that lasts more than 4 hours
What is the major vascular difference between an erect and a flaccid penis?
In a flaccid penis the arterio-venous anastomoses allow blood to bypass the corpus cavernosum
Describe the nervous component of ejaculation
Sympathetic brings about ejaculation: L1-2
- Closes the internal urethral sphincter
- Peristalsis of ductus deferens and seminal vesicles
- Prostate smooth muscle contraction
What innervates the somatic muscles of erection and ejaculation?
Branches of the pudendal nerve; S2-4
What are major lymphatic nodes that drain the male repro tract?
- Superficial inguinal; scrotal, penile and perineal skin
- Deep inguinal; glans of penis, distal spongy urethra
- Para-aortic; testicles
- Internal iliac; corpus cavernosum, urethra (membranous and proximal spongy), most of the prostate, seminal vesicles and ducts
Describe the pelvic floor
A bowl-shaped sheet of muscle that supports the pelvic viscera and assists with sphincters
Describe the journey of sperm, from its creation to its release
- Spermatozoa are released into the lumen of seminiferous tubules (following spermiogenesis)
- They travel through the rete testis, ductulli efferentes, epididymis and vas deferens
- They are released into the ejaculatory duct (along with secretions from the seminal vesicle and prostate), and into the prostatic urethra!
