Male Anatomy Flashcards
What is the scrotum derived from?
What is it homologous to in females?
Genital folds which fuse in the midline, marked by scrotal raphae
Labia majora
Contents of the scrotum?
Testis
Epididymis
Spermatic cord
Dartos muscle - a sheet of smooth muscle immediately underneath skin which wrinkles it to reduce heat loss
Vascular supply to the scrotum?
Anterior scrotal artery derived from the external pudendal artery
Posterior scrotal artery derived from the internal pudendal artery
Scrotal veins follow arteries and drain into the external pudendal vein
Cutaneous innervation to the scrotum?
Genital branch of genitofemoral nerve - derived from femoral plexus and supplies anterolateral scrotum
Anterior scrotal nerves - from ilioinguinal nerve, supplies anterior aspect
Posterior scrotal nerve derived from perineal nerve - posterior aspect of scrotum
Perineal branches of posterior femoral cutaneous nerve - derived from sacral plexus, inferior aspect
Lymphatic drainage of the scrotum?
Superficial inguinal nodes
Causes of scrotal swelling?
Inguinal hernia Hydrocoele Haematocoele Varicocoele Epididymitis
What is an indirect inguinal hernia?
Reopening of the processus vaginalis
What is a hydrocoele?
Collection of serous fluid within the tunica vaginalis
Most commonly due to failure of the processes vaginalis to close
What is a haematocoele?
Collection of blood in the tunica vaginalis
How to distinguish between a haematocoele and a hydrocoele?
Transillumination
Light won’t pass through blood
What is a varicocoele?
Dilation of the veins that drain the testes
Which side is more commonly affected in a varicocoele?
Left testicle more commonly affected as left testicular vein drains into a smaller vessel, left renal vein, at a perpendicular angle
Presentation of a varicocoele?
Can look and feel like a bag of worms
What is the scrotum?
A fibrosus ulnar cutaneous sac
Dual chambered, forming an expansion of the perineum
Where is the epididymis located in relation to each testicle?
Posterolateral aspect of each testicle
What are the testes suspended from the abdomen by?
The spermatic cord
How do the testes descend during development?
Follow an evagination of peritoneum as they descend - the processus vaginalis which buds off from the peritoneum to form the tunica vaginalis
Begins on posterior abdominal wall, descend through the inguinal canal to the scrotum
Where are sperm stored?
In the epididymis
What are the testes covered in?
Covered externally by tunica vaginalis anteriorly and on the sides
Tunica albuginea is a fibrous capsule which penetrates into the parenchyma, dividing the testicle into lobules
What are the parts of the epididymis?
A single coiled tube
Head - formed by efferent tubules
Body - heavily coiled duct
Tail - most distal part, marks origin of the vas deferens
Innervation of the testes and epididymis?
Testicular plexus derived from renal and aortic plexi
Receives autonomic and sensory fibres
Vascular supply of the testes and scrotum?
Testicular arteries which arise directly from abdominal aorta at L2/3
Pass into the scrotum via the inguinal canal
Venous drainage - testicular veins (left into renal vein…)
Lymphatic drainage of testes and epididymis?
Lumbar and preaortic lymph nodes at L1
Anatomical course of the spermatic cord?
Formed at opening of the inguinal canal in the deep inguinal ring, lateral to inferior epigastric vessels
Passes through the canal, enters the scrotum via superficial ring
Ends at posterior border of the testes
Where are the fascial coverings of the spermatic cord derived from?
Anterior abdominal wall
What are the fascial coverings of the spermatic cord?
External spermatic fascia - derived from aponeurosis of external oblique
Cremaster muscle and fascia - derived from internal oblique and its fascial coverings
Internal spermatic fascia - derived from transversalis fascia
What are those three fascial layers of the spermatic cord covered in?
Superficial fascia which lies directly below the scrotal skin
What does the cremaster muscle form?
A discontinuous layer of striated muscle, orientated longitudinally
What is the cremasteric reflex? Spinal reflex pathway?
If superior medial thigh is stroked, produces an immediate contraction, elevating testes on that side
Afferent limb - iliolingual/genitofemoral nerve
Efferent limb - genital branch of genitofemoral nerve
Contents of the spermatic cord?
Testicular artery
Cremasteric artery and vein (supplying cremasteric muscle and fascia)
Artery to vas deferens (branch of inferior vesicle, of internal iliac)
Pampiniform plexus of testicular veins
Genital branch of genitofemoral nerve
Vas deferens
Lymph vessels - drain into para-aortic nodes
Processus vaginalis
Autonomic nerves
What is the vas deferens?
Thick muscular tube conveying sperm from epididymis to ejaculatory duct
Structure of the wall of the vas deferens?
3 smooth muscle layers
Inner and outer longitudinal, middle circular
Anatomical course of the vas deferens?
Continuous with tail of epididymis
Travels through inguinal canal
Moves down lateral pelvic wall in close proximity to the ischial spine
Turns medially to pass between the bladder and urethra
Joins duct from seminal vesicle to form the ejaculatory duct
What is testicular torsion?
Complications?
When the spermatic cord twists upon itself
Occlusion of testicular artery causing necrosis of testes
How to diagnose testicular torsion?
Ultrasound and colour Doppler scanning
Present with severe sudden pain in one of both testes
Often from exercise/physical activity
What is a spermatocoele?
Retention cyst within the epididymis
