Session 4 Reproduction Flashcards
What is the scrotum and it’s embryological origin?
Fibromuscular cutaneous sac which is an extension of the perineum.
Origin from the genital swellings, these swelling will fuse to form the scrotal raphe.
What is contained in the scrotum?
Spermatic cord, epididymis & the testis
What are the layers of the scrotum ?
- Skin
- Dartos muscle and fascia
- External spermatic fascia
- Cremaster muscle and fascia
- Internal spermatic fascia
- Tunica vaginalis (parietal and visceral layer)
- Testis ( tunica albuginea)
What is the function of the dartos muscle ?
This is SMC which will contract to wrinkle the skin (note it is situated directly below the skin of the scrotum). This will decrease the surface area to decrease heat loss in its role in regulating spermatogenesis.
What is the origin of the cremaster muscle and what is its role in the scrotum?
The cremaster muscle comes from the internal oblique.
It is a skeletal muscle
It’s role is in elevating the testis to also regulate temperature of the testis (when elevated closer to the body and therefore warmer if needed)
What is the lymphatic drainage of the scrotum ?
They drain into the superficial inguinal lymph nodes .
These are palpable on the inferior border of the inguinal ligament on the medial aspect of the thigh. There are horizontal and vertical lymph nodes here.
What is a variocele ?
Dilation of the veins in the region of the scrotum. (The pampiniform plexus). This will then cause the scrotum to be enlarged and feel like a bag of worms.
Where is a variocele most likely to occur?
Most likely to occur on the left hand side as a result of the fact the left testicular vein is on longer, drains into the smaller left renal vein, and enters this vein at a perpendicular angle.
What is a hydrocoele ?
This is where there is fluid (serous) in the tunica vaginalis. This is often due to a failure of the closure of the processus vaginalis, or there is some infection of this region.
What is a haematocoele?
This is where there is blood in the tunica vaginalis and this is due to trauma (most commonly) or also due to infection.
What kind of hernia can appear in the scrotum ?
Indirect inguinal hernia.
This is where the contents of the abdomen can pass through the inguinal canal through the deep and superficial ring to emerge medially to the inferior epigastric vessels to then descend in to the scrotum, the extent of the descent is enabled by the amount of processus vaginalis still present and patent.
What are the common causes of scrotal enlargement ?
Indirect inguinal hernia Haemaotcoele Hydrocoele Variocoele Epididymitis
What is transillumination and why is it important ?
Processor of shining light on the scrotum.
Differentiate between solid and also liquid.
Also between blood and serous fluid.
What are the effects of an enlarged scotrum?
Pain, distension of the scrotum, infertility, inability to get erect, systemic features ( fever, tiredness, lethargy).
Where does the spermatic cord run from and to?
It originates from the deep inguinal ring and will pass through the inguinal canal to end finally at the posterior border of the testis.
What are the coverings of the spermatic cord?
External spermatic fascia ( from aponeurosis of ext. oblique)
Cremasteric fascia and muscle (from internal oblique)
Internal spermatic fascia ( from the t. Fascia)
What are the contents of the spermatic cord ?
Testicular artery, cremasteric artery, artery to the vas deferens
Pampiniform plexus
Lymphatics
Genital branch of the genitofemoral nerve (lumbar plexus)
Vas deferens
Remnants of the processus vaginalis
What is the function of the pampiniform plexus?
It wraps around the testicular artery to act as a heat exchanger to ensure there is no elevated rise in temperature which would impair gametogenesis.
Where does the pampiniform plexus drain into ?
The right hand side will drain into the right testicular vein and then into IVC.
The left hand side -> left testicular vein -> left renal vein -> IVC.
What is the trajectory of the vas deferens?
It will originate from the tail of the epididymis, travels through inguinal canal, come up the lateral pelvic floor close to the ischial spine and turn medially to pass between the bladder and the urethra. It joins the duct of the seminal vesicle to become the ejaculatory duct.
What is testicular torsion?
This is where the testicle has twisted toward the midline of the body and in turn has twisted the spermatic cord, which then causes the blood supply to the testis to be cut off, and therefore there is Ischaemia and necrosis of the testis.
What are the symptoms of testicular torsion ?
Sudden and severe onset of pain.
Mild systemic features also present.
Nausea and vomiting.
It is often preceeded by excercise or physical activity.
Nerves from which branch innervate the posterior, inferior and anterior scrotum?
Anterior -> from the lumbar plexus
Posterior and inferior -> from the sacral plexus
What is the lymphatic drainage of the testis?
The paraaortic and lumbar nodes (located at L1)
What is the arterial supply of the testis ?
The testicular artery, artery from the abdominal aorta directly below the origin of the Renal artery.
What is the tunica albigunea?
Tough outer covering of fibrous material which will also line the inner aspect of the testis forming septa which Seperate the testis into functional lobules.
