Abdomen and Pelvis 
against the bladder when the latter is distended. 
The vesicular gland discharges dorsally into the 
urethra through the ductus excretorius, situated 
near the ejaculatory duct. During summer, these 
glands weigh ten times more than they do in the 
winter months (Tables 4, 6, 16, 16a). They are 
grayish-white in color, up to 25 mm long, and their 
surfaces are nodular. Internally, each gland has a 
spacious, central main duct which gives rise to 
lateral ducts, ramifying as diverticula and ending 
blindly. 
The vesicular glands have three layers: an external areolar sheath 
(tunica adventitia); a two-layered middle muscular sheath (tunica 
muscularu). thinner than that of the ductus deferens, which includes 
an outer longitudinal and inner circular layer; and an internal mucous 
coat (tunica mucosa) with a reticular structure. The epithelium is col- 
umnar or flat, depending upon its functional state (Fig. 5-68), and 
goblet cells, the secretion of which increases the volume of the seminal 
fluid, are present in the diverticula. 
5.8.3.2 Prostate Gland 
The prostate gland (prostata) appears as flat- 
tened bodies composed of many glandular lobules 
separated from one another by loose connective 
tissue. The two largest lobes lie dorsal and lateral 
to the base of the urinary bladder and ventral to the 
caudal segment of the ductus deferens. Three small- 
er lobes are situated ventral to the neck of the 
bladder and the end of the ampulla of the ductus 
deferens. From the glandular lobes of the prostate 
several efferent ducts [ductuli pro static i) enter the 
urethra dorsolaterally. During hibernation, these 
glands are barely recognizable macroscopically. 
Prostate weights and sizes are given in Table 15. 
Unlike the rat (Wells, 1968), no paraprostate is 
present. 
The muscular tissue constitutes the stroma of the prostate, the con- 
nective tissue being very scanty and merely forming thin trabeculae 
between the muscle fibers where the vessels and nerves of the gland 
ramify. The glandular substance is composed of numerous follicles with 
frequent internal papillary elevations. The lining of the canals and 
follicles is of the simple columnar variety (Fig. 5-69). 
5.8.3.3 Bulbourethral Gland 
The bulbourethral glands {gll. bulbourethrales) 
are paired small, rounded, somewhat lobulated, 
lentil-sized, yellowish bodies, about 5 mm in di- 
ameter (Fig. 5-59; Table 17). They are positioned 
at the caudal border of the ischial tuberosity {tuber 
ischiadicum), almost in the middle of the penis and 
are surrounded by striated musculature. Each dis- 
charges its secretion through a separate thin duct 
{ductus gl. bulbourethralis ) into the urethra at the 
root of the penis. 
Each lobule consists of a number of acini lined with colufnnar 
epithelial cells. 
5.8.4 Penis 
The penis is the male organ of copulation and 
comprises a glans {glans penis), a body {corpus 
penis) and a root {radix penis), all of which lie sub- 
cutaneously, enclosed within the prepuce (prae- 
putium). The fibrous penis of the European ham- 
ster originates in two crura arising from the ischial 
arch. When lying within the prepuce, it has the 
form of a cylinder kinked about 90° (Fig. 5-70) and 
is approximately 30 mm long when erected. 
Its dorsal surface {dorsum penis) is flat while its 
ventral urethral surface {sulcus urethralis) forms a 
deep groove. The erectile mechanism is based on 
two parallel and anastomosing corpora cavernosa, 
both of which are invested by a compact connective 
tissue sheath {tunica albuginea corporum caverno- 
sorum). The urethra is partially surrounded ven- 
trally by m. ischiourethralis. Many microscopically 
visible mucosal papillae are found on the surface of 
the glans penis. At the apex of the glans, the mucosa 
forms a circular fold and the urethra discharges 
into its ventral surface {ostium urethrae externum). 
The OS penis is located in the apex of the corpus 
cavernosum, covered by the glans, and is a small 
pyramid shaped bone (Kittel, 1953). 
The prepuce is composed of external and internal 
laminae {laminae externa et interna), which ex- 
hibit many macroscopic rugae. The large praeputial 
glands {gll. praeputiales) form paired submucosal 
cylindrical structures. 
The corpora cavernosa, which confer a spongy 
consistency to the fibroelastic penis, are lined with 
endothelium only in the area of the root. The tra- 
beculae are composed of white fibrous tissue, elastic 
fibers and nonstriated muscle fibers; they are richly 
vascularized and innervated. The cavernous spaces 
are filled with blood during erection. In an erected 
state, the penis lies along the abdominal wall 
oriented cranially, as opposed to the caudal orien- 
tation when lying subcutaneously. 
137 
