Page 820 - Atlas of Histology with Functional Correlations

The bulbourethral glands are small, pea-sized glands located at the root of

the penis and embedded in the skeletal muscles of the urogenital diaphragm;
their excretory ducts terminate in the proximal portion of the penile urethra.

The penis consists of erectile tissues, the paired dorsal corpora cavernosa
and a single ventral corpus spongiosum that expands distally into the glans
penis. Because the penile urethra extends through the entire length of the corpus

spongiosum, this portion of the penis is also called the corpus cavernosum
urethrae. Each erectile body in the penis is surrounded by the connective tissue
layer tunica albuginea.

The erectile tissues in the penis consist of irregular vascular spaces lined

with a vascular endothelium. The trabeculae between these spaces contain
collagen and elastic fibers and smooth muscles. Blood enters the vascular spaces
from the branches of the dorsal artery and deep arteries of the penis and is
drained by peripheral veins.

Supplemental micrographic images are available at
www.thePoint.com/Eroschenko13e under Male Reproductive System.

FIGURE 20.16 | Prostate Gland and Prostatic

Urethra

The prostate gland is an encapsulated organ situated inferior to the neck of the
bladder. The urethra that leaves the bladder and passes through the prostate
gland is the prostatic urethra (1). A transitional epithelium (6) lines the

lumen of the crescent-shaped prostatic urethra (1). Most of the prostate gland
consists of branched tubuloacinar prostatic glands (5, 11) with some exhibiting
solid secretory aggregations called prostatic concretions (11) that appear as small
red dots in this illustration. A characteristic fibromuscular stroma (10) with

smooth muscle bundles (4) mixed with collagen and elastic fibers surrounds the
prostatic glands (5, 11) and the prostatic urethra (1).

A longitudinal urethral crest of fibromuscular stroma without glands widens
in the prostatic urethra (1) to form a domelike structure called the colliculus

seminalis (7) that protrudes into and gives the prostatic urethra (1) a crescent
shape. On each side of the colliculus seminalis (7) are the prostatic sinuses (2)
into which open the excretory ducts of the prostatic glands (9).

In the middle of the colliculus seminalis (7) is a cul-de-sac called the utricle

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