Page 504 - Concise Pathology for Exam Preparation ( PDFDrive )

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Male Genital Tract
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TESTIS AND EPIDIDYMIS
Normal Structure

• The scrotal sac lodges the testis and the epididymis along with the lower part of
spermatic cord.
• The testes are a pair of ovoid glandular structures that are responsible for the production
of sperms and the male sex hormone testosterone.
• They are invaginated by the tunica which has three layers, namely, the tunica vasculosa,
albuginea and vaginalis. Tunica vasculosa is the innermost connective tissue layer of the
tunica which carries blood vessels to the testis. It is covered by the tunica albuginea
which encases the testis and also extends into it. Overlying this is the outer layer of the
tunica, the tunica vaginalis.
• Each testis is divided by invaginations of the tunica albuginea into small compartments
called lobules. Each lobule contains numerous tightly coiled seminiferous tubules, the
walls of which contain the germ cells, Sertoli cells and Leydig cells.
• The germ cells multiply and differentiate to produce spermatocytes from the onset of
puberty. The spermatocytes develop into spermatids and eventually spermatozoa. About
400 million sperms are released in a single ejaculation. Sertoli cells provide support to
the developing sperm cells. The seminiferous tubules are held together by loose connec-
tive tissue called interstitium which lodges the Leydig cells. Leydig cells produce
testosterone that is responsible for the secondary sex characteristics associated with males.
• The tubules become less convoluted towards the lobular apex and continue as 20–30
straight collecting ducts. These ducts merge to form the rete testis lined by flattened
epithelium. The secretions from rete testis drain into the vasa efferentia which opens
at the upper pole of the epididymis. The lower pole of the epididymis merges with the
ductus deferens.

Q. Write briefly on cryptorchidism.

Ans. Cryptorchidism is derived from the Greek words kryptos, meaning hidden and
orchis, meaning testicle and indicates the absence of one or both testes from the scrotum.
It has the following salient features:
• It is usually seen at birth but can rarely develop later in life. About 80% of cryptorchid
testes descend by the first year of life making the actual incidence about 0.8%.
• The exact cause is not known but the risk factors include intrauterine growth retardation,
prematurity, perinatal asphyxia, C-section and toxaemia of pregnancy.
• An undescended testis can be found anywhere along the ‘normal path of descent’ from
the retroperitoneum (25% cases) to the inguinal ring (70% cases) or any other location
in the inguinal canal (5% cases).
• It is sometimes found outside the normal pathway, eg, the thigh, the perineum, the
opposite scrotum or the femoral canal, when it is labelled ectopic or wandering testis. An
underdeveloped undescended testis is labelled hypoplastic.
• In rare cases, the testis appears to have vanished (true hidden testes or ‘anorchia’).

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