The Male Reproductive Tract Flashcards
Where are the testes originally formed? What stage do they descend into the scrotum?
Near the kidneys then they descend to scrotum at approximately 28 weeks of foetal life.
How are the testes guided into the scrotum during development?
By the gubernaculum. It is connected to the destination point of the testes and it doesn’t lengthen with development so as the abdomen grows it pulls the testes down into the scrotum.
The walls descend alongside the testes and the fold of peritoneum creates the vaginal process. This then fuses with the peritoneal fold anterior to the testes superiorly forming a space in the testes called the tunica vaginalis.
Why are people with undescended testes infertile?
Testes are highly sensitive to temperature
What is the name of the condition where the testes are undescended?
Cryptorchidism
How is the tunica vaginalis of the scrotum formed?
The walls descend alongside the testes and the fold of peritoneum creates the vaginal process. This then fuses with the peritoneal fold anterior to the testes superiorly forming a space in the testes called the tunica vaginalis. This creates a visceral and parietal layer.
How do the muscles of the scrotum develop?
They are extensions of the abdominal wall muscles.
The internal spermatic fascia is derived from the transversalis fascia)
The cremasteric fascia is derived from the itnernal oblique muscle
The external spermatic fascia is derived from external oblique muscle.
Where does the spermatic cord go in the adult?
It passes through the inguinal canal.
What structures make up the inguinal canal?
Anterior wall and floor: External oblique muscle
External inguinal ring is a slit in fibers of the external oblique aponeurosis above pubic tubercle.
Posterior wall is made up of transversalis fascia.
Internal inguinal ring is midway between anterior superior iliac spine and pubic tubercle above the inguinal ligament.
Roof of canal is formed by fibers of internal oblique and transversus abdominsis
What forms the anterior wall and the floor of the inguinal canal?
External oblique muscle
What forms the external inguinal ring of the inguinal canal?
Slit in fibers of external oblique aponeurosis above pubic tubercle.
What forms the posterior wall of the inguinal canal?
Transversalis fascia
What forms the itnernal inguinal ring of the inguinal canal?
Midway between anterior superior iliac spine and pubic tubercle above the inguinal ligament
What forms the roof of the inguinal canal?
Fibers of internal oblique and transversus abdominis
What can potentially result from inguinal canal anatomy?
Inguinal canal is a weak point in the pelvic wall and so increased abdominal pressure can result in herniation of abdominal viscera into the inguinal canal.
How is an inguinal hernia repaired?
Polypropylene mesh is used. This is associated with infertility.
How is temperature regulated in the testes?
Cremaster muscle is present in spermatic cord and surrounds testes. It functions to keep testes close to body when cold.
Dartos muscle is just deep to the skin and affects how wrinkled the skin is around the testes.
Abundant sweat glands and a pampiniform plexus which is a venous plexus that runs alongside the testicular artery (countercurrent exchange)
What lymphatics drain the testes?
Superficial tissue drains into superficial inguinal nodes.
Glans drains into deep inguinal nodes and external iliac nodes.
The testes themselves drain into the lateral aortic and pre-aortic nodes.
Where is sperm produced?
In the seminiferous tubules.(3 to 4 seiminiferous tubules per lobule)
