CHAPTER 18
Male Reproductive System
345
Figure 18-14C
Rete Testis
Figure 18-15A,B
Ductuli Efferentes
Figure 18-15C
Clinical Correlation: Testis Seminoma
Extratesticular Genital Ducts
Figure 18-16
Ductus Epididymis
Figure 18-17A,B
Epithelium of the Ductus Epididymis
Figure 18-18A
Ductus Deferens, Spermatic Cord
Figure 18-18B,C
Ductus Deferens
Figure 18-19A,B
Ejaculatory Duct, Prostate Gland
Figure 18-19C
Epithelium of the Prostatic Urethra
Accessory Genital Glands
Figure 18-20A,B
Prostate Gland
Figure 18-20C
Clinical Correlation: Prostate Cancer
Figure 18-21A,B
Seminal Vesicles
Figure 18-21C
Seminal Vesicle with Seminal Fluid
Penis
Figure 18-22
Overview of the Penis
Synopsis 18-3
Clinical and Pathological Terms for the Male Reproductive System
Introduction and Key Concepts for the
Male Reproductive System
The
male reproductive system
is composed of (1) a pair of
testes
where spermatogenesis takes place; (2) a series of
genital ducts
that include
intratesticular genital ducts
and
extratesticular
genital ducts
(which function to carry spermatozoa from the
testes to their destination); (3) three major accessory genital
glands: the
prostate gland, seminal vesicles
, and
bulbourethral
glands
; and (4) the
penis
, which is the male copulatory
organ. The main functions of the male reproductive system
include production of spermatozoa, fertilization of the
ovum in the female reproductive tract, production of sex
hormones (testosterone) to develop and maintain secondary
male sex characteristics, and performance of sexual activity
(copulation).
Testis
The
testis
consists of numerous convoluted
seminiferous
tubules
that are lined by
seminiferous epithelium
supported
by a basement membrane. The seminiferous epithelium
hosts various stages of
spermatogenic cells (spermatogonia,
spermatocytes
, and
spermatids
), which are protected,
nourished, and supported by
Sertoli cells
. The Sertoli cells also
produce
testicular fl
uid
, anti-Müllerian hormone, androgen-
binding protein (ABP), etc. Between the seminiferous tubules,
there is loose connective tissue that contains a special type of
cells called the
interstitial cells of Leydig
. These cells mainly
produce
testosterone
hormone that promotes
spermatogenesis
and the development of male sexual organs as well as maintains
secondary male sexual characteristics. The testis is covered by
the
tunica albuginea
(capsule),
tunica vaginalis
(mesothelial
sac), and an outer layer of wrinkled thin skin, the
scrotum
.
Spermatogenesis takes place in the seminiferous epithelium of
the tubules (see Figs. 18-9 to 18-13B).
Intratesticular Genital Ducts
The
intratesticular genital ducts
are located within the testis,
including the
tubuli recti, rete testis
, and
ductuli efferentes
.
1.
Tubuli recti
: These are short, straight tubules lined by
simple cuboidal epithelium
. They carry the newly produced
spermatozoa in testicular fl uid from the seminiferous tubules to
the rete testis in the mediastinum of the testis (Fig. 18-14B).
2.
Rete testis
: This is a maze of anastomosing tubules with an
irregular lumen and is lined by
simple cuboidal epithelium
(Fig. 18-14C). This network of interconnecting tubules
conducts the sperm atozoa and testicular fl
uid into the
ductuli efferentes.
3.
Ductuli efferentes
: These convoluted tubules are alternatively
lined by two cell types:
nonciliated cuboidal cells
and
ciliated
columnar cells
. The ductuli efferentes absorb some testicular
fl uid and move the spermatozoa to the head of the epididymis
(Fig. 18-15A,B).
Extratesticular Genital Ducts
The
extratesticular genital ducts
located outside the testis
include the
ductus epididymis
,
ductus deferens
,
ejaculatory
ducts
, and
urethra
. These ducts are paired tubules except the
urethra, which is a single tubule.
previous page 360 Dongmei Cui -  Atlas of Histology with Functional and Clinical Correlations 2011 read online next page 362 Dongmei Cui -  Atlas of Histology with Functional and Clinical Correlations 2011 read online Home Toggle text on/off