CHAPTER 18
Male Reproductive System
365
Figure 18-19A.
Ejaculatory duct, prostate gland.
H&E,
3
11
The ampulla of the ductus deferens continues after it joins
with the duct of the seminal vesicle to form the
ejaculatory
duct
. The two ejaculatory ducts pass through the prostate
gland to join with the urethra. Each ejaculatory duct is a
short, straight tube (1–2 cm in length) and has a thin wall
lined by
pseudostratif
ed
(or
simple
)
columnar epithelium
and supported by connective tissue. Smooth muscle is pres-
ent in the initial segment but disappears in most of the
ejaculatory ducts. Here is an example of the two ejacula-
tory ducts within the prostate gland, surrounded by large
amounts of connective tissue. The mucosa forms many folds
extending into the lumen. The lumen may contain
prostatic
concretions
(secretory material of the prostatic gland and
often seen in older male patients).
Fold of the
Fold of the
mucosa
mucosa
Fold of the
mucosa
Connective tissue
C
o
n
n
e
c
t
i
v
e
t
i
s
s
u
e
Connective tissue
Prostate
Prostate
gland
gland
Prostate
gland
Prostate
Prostate
gland
gland
Prostate
gland
Ejaculatory ducts
Ejaculatory ducts
Ejaculatory ducts
A
Ejaculatory duct
Prostatic
urethra
Fig. 18-19C
Prostate
Prostate
gland
gland
Prostate
gland
Ejaculatory duct
Prostatic
Prostatic
concretion
concretion
Prostatic
concretion
B
Figure 18-19B.
Ejaculatory duct, prostate gland.
H&E,
3
34
The
ejaculatory ducts
penetrate the prostate gland and open
into the
prostatic urethra
, at the
seminal colliculus
(also
called the
verumontanum
), on the posterior wall of the pro-
static urethra. This portion of the urethra has thick mucosa
and shallow folds as shown here. The function of the ejacu-
latory ducts is to transport spermatozoa and seminal fl
uid
into the prostatic urethra. The urethra includes three parts:
the
prostatic urethra
(proximal part, near the bladder), the
membranous urethra
(intermediate part), and the
penile
(spongy) urethra
(distal part). Prostatic concretions, also
called
corpora amylacea
, are present in the lumen of the
prostate gland shown here (Fig. 18-20B).
Transitional
epithelium
Prostatic
urethra
Duct of prostate gland
Simple columnar
Simple columnar
epithelium
epithelium
Simple columnar
epithelium
Duct of prostate gland
C
Figure 18-19C.
Epithelium o± the prostatic urethra.
H&E,
3
272
Where the two ejaculatory ducts merge with the prostatic
urethra, the epithelium changes from simple or pseudostrati-
± ed columnar to the transitional epithelium that is character-
istic of the urinary system. Here is an example of
prostatic
urethral epithelium
at higher magni± cation; it is taken from
the
dashed box
indicated in Figure 18-19B. The epithelium
of the duct of the prostate gland is simple columnar epithe-
lium with round nuclei. The prostatic secretions are delivered
into the prostatic urethra through numerous small ducts of
the prostate gland.
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