Male External Genitalia and Perineum

Remember that the spermatic cord is special in that it contains many "coverings". These coverings include:

- External spermatic fascia, from external oblique muscle, - Cremasteric fascia and muscle, from internal oblique muscle, and - internal spermatic fascia, from transversus abdominis

What is the blood supply and venous drainage of the testis?

Blood supply is the testicular artery and the pampiniform plexus is the venous drainage.

In the embryo, the scotum forms as an out-pouching of the anterior abdominal wall. Interestingly, the scrotum contains each layer within the covering, except fat. The superficial fascia, which normally houses fat, is known as what in the scrotum?

Dartos Fascia is the superficial layer above the scrotum. Dartos fascia contains smooth muscle fibers, known as dartos muscle.

What is its function of the epididymis?

Overall, the epididymis functions to store spermatazoa and promote maturation, eventually draining the mature sperm into the vas deferens for transportation.

Pelvic splanchnic nerves are made of what spinal levels?

Pelvic splanchnic nerves are made up of spinal levels S2, 3, and 4, which keeps the penis off the floor by causing an erection. S2, 3, and 4 contain parasympathetic fibers.

Name the structures found in the spermatic cord.

Structures found in the spermatic cord include: - The testicular, and cremasteric artery, - The genital branch of the genito-femoral nerve and the ilioinguinal nerve, - Vas deferens, - Pampiniform plexus, - lymphatic vessels, and - the Tunica Vaginalis, which is embryologically derived from the processus vaginalis.

What occurs during a vasectomy?

The ductus deferens can be surgically interrupted in the superior part of the scrotum. Note, that sperm production still continues but the spermatozoa cannot reach the urethra.

Note, that due to the fact that the spermatic cord contains many cord-like structures, it may be difficult to tell them apart. How can we distinguish them?

The ductus deferens is a hard, cord-like structure. It has a small arterial vessel that is located on its surface, intimately, known as the artery of the ductus deferens. The testicular artery can be distinguished from the pampiniform plexus by its slightly thicker and tortuous course. All other cords are too small to worry about.

Although the visceral layer covers most of the testis, the posterior aspect of the testis is not covered by it. This is because there is a structure known as what?

The epididymis makes up the posterior-inferior aspect of the testis.

There are three parts of the epididymis. Name them.

The head (caput), the body (corpus), and the tail (cauda) make up the epididymis. The head receives efferent ductules. The body is narrower in diameter than the head. The tail is the most inferior part that turns superiorly to join the ductus deferens.

Where do lymphatics drain from the scrotum?

The lymphatics from the "scrotum" drain into superficial inguinal lymph nodes. This means that inflammation in the scrotum is accompanied by a tender and enlarged groin.

Where do lymphatics drain from the testis?

The lymphatics of the testis follow the testicular vessels, through the inguinal canal, into the lumbar (lateral aortic) and pre-aortic lymph nodes (near the lumbar arteries). Testicular tumors may metastasize to lumbar and pre-aortic lymph nodes, not to superficial inguinal lymph nodes.

What is the pathway of sperm?

seminiferous tubule in the testis, to the head, body, and tail of the epididymis, to the duct and ampulla of the ductus deferens, to the ejaculatory duct of the prostate, and lastly, to the prostatic urethra.

What is the name for the band of tissue that anchors the inferior pole of the testis to the scrotum?

The scrotal ligament --- The scrotal ligament is the embyrological remnant of the "gubernaculum testis". It is found at the most inferior aspect of the scrotum.

What divides the scrotum into two compartments?

The scrotal septum divides the scrotum into two compartments. It is made of superficial fascia, known as dartos fascia.

The testis are suspended by what structure?

The spermatic cord.

What is the name for the the layer deep to the tunica vaginalis, which covers the testis? How is it differentiated between the tunica vaginalis (and its two layers)?

The tunica albuginea --- the tunica albuginea is a thick covering over the testis. It is also found on other parts of the male external genitalia, but in the testis, continues to form a septum inside the testis. This septum is known as the mediastinum septum, housing "rete testis". These "septa" divide the testis into lobules.

A serous sac that covers the testis, within the scrotum, is derived from peritoneum. What is the name of this serous sac. Essentially, it makes up two layers, a visceral and parietal layer.

The tunica vaginalis, a serous sac of peritoneum, covers the testis within the scrotum. It is derived from the processus vaginalis. It contains a parietal (within sac) and viseral (on testis) layer. The cavity of the tunica vaginalis is only a potential space that contains very small amount of serous fluid.

What is contained with the lobules of the testis?

Within the lobules, seminiferous tubules are contained.