What is the embryological origin of the testis and epididymis?

The testis develops from the genital ridge on the posterior abdominal wall, while the epididymis forms from remnants of the mesonephric system: efferent ductules from mesonephric tubules and the duct of epididymis from the mesonephric (Wolffian) duct.

What are the key embryological remnants associated with the testis and epididymis?

Several remnants can persist, including the appendix of testis (from the paramesonephric duct), appendix of epididymis or Hydatid of Morgagni (from the mesonephric duct), and paradidymis or Organ of Giraldes (from caudal mesonephric tubules). These may form cysts near the testis or epididymis.

How does the testis descend during development?

The testis descends from the posterior abdominal wall to the scrotum over months, moving through stages from the abdomen to the iliac fossa, inguinal canal, and into the scrotum by birth, driven by factors like temperature regulation for spermatogenesis.

What factors influence the descent of the testis?

Key factors include differential growth, increased intra-abdominal pressure, testicular and maternal hormones, the gubernaculum (a fibromuscular band that guides descent), and CGRP (calcitonin gene-related peptide) from the genitofemoral nerve.

What is cryptorchidism and how does it differ from ectopic testis?

Cryptorchidism is an undescended testis that follows the normal path but fails to reach the scrotum, often leading to infertility and increased cancer risk. Ectopic testis involves maldescent along an abnormal path to sites like the perineum, usually developing normally but prone to trauma.

What are the common complications of an undescended testis?

Complications include infertility due to poor sperm production and an increased risk of malignancy. Management typically involves surgical descent (orchidopexy) before puberty to mitigate these risks.

What is the role of the gubernaculum in testicular descent?

The gubernaculum is a fibromuscular band that shortens and guides the testis during descent from the abdomen to the scrotum, playing a crucial role in positioning it correctly.

Testis Descent – Development & Anomalies

❓ Frequently Asked Questions