4. Anatomy of the Male Reproductive System and Osteology of the Pelvis Flashcards
What is the scrotum?
A cutaneous fibro-muscular sac for the testes and associated structures.
Where is the scrotum?
Posteroinferior to the penis and inferior to the pubic symphysis.
What is the scrotal raphe?
The mid-line which is continuous with the penile raphe and indicates the bilateral embryonic formation of the scrotum.
What are the two compartments of the scrotum?
One for each testis diving by the septum of the scrotum.
What are the testes?
Male gonads. Paired, ovoid reproductive glands that produce spermatozoa and male hormones.
Where are the testes?
Suspended in the scrotum by spermatic cords.
What are the tests covered by?
Visceral layer of tunica vaginalis. Parietal layer of tunica vaginalis adjacent to internal spermatic fascia. Fluid in between two layer, small amount for free movement of the testis in the scrotum.
What is the tunica albuginea?
The tough, fibrous outer surface of the testes that thickens into a ridge on internal, posterior aspect as mediastinum of testis.
How are seminiferous tubules joined?
By rete testis = network of canals in the mediastinum of the testis.
What are Sertoli cells associated with and what do they do?
Seminiferous tubules, spermatozoa development.
Where are Leydig cells and what do they do?
Cells in the interstitial tissue (hence aka interstitial cells) and they secrete testosterone.
Where do the testes arise?
In the mesonephric ridge in the upper lumbar regions, at the lower pole of the kidneys. They’re tethered to labioscrotal folds, by the gubernaculum.
How do the testes descend?
As the body grows, the testis becomes relatively more caudal. A musculo-fascial layer evaginates into the scrotum as it develops with peritoneal membrane to form the processes vaginalis.
What do the testes cross and exit in their descent?
Inguinal canal and exit the anterolateral abdominal wall.
What forms the spermatic cord?
The fascia and peritoneum become closely apposed. So fascial layers, obliterated stem of processus vaginalis, vas deferens, testicular vessels and nerves.
What occupies the inguinal canal in males?
The spermatic cord.
What is the scrotal ligament?
The vestigial remnant of the gubernaculum.
What is the arterial supply to the testes?
Direct from the abdominal aorta. The long, testicular arteries arise just inferior to the renal arteries.
What is the course of testicular arteries?
Pass retroperitoneally and cross over the ureters and the inferior part of the external iliac arteries to reach the deep inguinal rings. They then pass through the inguinal canal, emerge through superficial inguinal rings, and enter spermatic cords.
What is the venous drainage of the testes?
Asymmetrical. Veins from testis and epididymis form pampiniform venous plexus, the veins converge superiorly to form right and left testicular veins.
Right testicular vein -> inferior vena cava.
Left testicular vein -> left renal vein.
What is an action of the pampiniform venous plexus?
Thermoregulatory system of the testis, it cools blood from the abdominal aorta as it passes through testicular artery as the testicular vein wraps around it.
What are the segment of the epididymis?
Head (caput), body (corpus), and tail (caudal) segments.
Where is the epididymis?
On the superior and psoterolateral surface of the testis.
What are the functions of the epididymis?
It connects to the seminiferous tubule via efferent ductules and rete testis. Functions: sperm transport, maturation, and storage.
What is the innervation of the testes and scrotum?
Lumbar plexus for anterior surface and sacral plexus for posterior and inferior surfaces.
What is the lymphatic drainage of the testes and scrotum?
Testes: drain to paraaortic nodes.
Scrotum: drains to superficial inguinal nodes.
What is the ductus (vas) deferens?
A straight muscular tube that emerges from the caudal epididymis and is contained within the spermatic cord.
What is the function of the ductus deferens?
To transport the sperms rapidly to the prostatic urethra.
How are the contents of the vas deferens propelled towards the ejaculatory duct?
Rich autonomic innervation permits rapid contractions of the muscular tube.
What does the ductus deferens do in ejaculation?
It and the duct of the seminal vesicle dilate to facilitate entry of sperms and seminal gland secretions into prostatic urethra.