Male reproductive organ
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Epididymis
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It is a coma-shaped body situated along the
lateral part of the posterior border of testis
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It is an organ that contains the efferent
ductules and the duct of the epididymis
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The efferent ductules are lined with pseudostratified
columnar epithelium
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A circular smooth muscle layer 1st appear at the
beginning of the efferent ductules
Duct of
epididymis
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It is lined with a pseudostratified columnar
epithelium. It contains principal cells and basal cells
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Numerous long, modified microvilli called
stereocilia extend from the luminal surface of the principal cells
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Epididymal cells function in both absorption and
secretion
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The smooth muscle coat of the duct of epididymis
gradually increases in thickness to become three-layered in the tail
Ductus deferens
is a thick cord-like tubular structure and is about 45 cm
Section
of the ductus deferens
- Section
of the ductus deferens showing the mucosa formed by pseudostratified
columnar epithelium with stereocilia and a lamina propria. The thick outer
wall is formed of smooth muscle (brown) and collagen fibers (blue).
- In epididymis, the lumen is smooth but
in d. deferens the lumen is thrown into deep longitudinal fold due to
contraction of the thick muscular coat.
Course and
relations of ductus deferens
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It begins from the tail of epididymis then
enters the spermatic cord and traverses the inguinal canal
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At the deep inguinal ring the vas leaves the
other constituents of the cord & ascend in front of the external iliac artery
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Next the vas crosses above and medial to the
terminal part of Ureter & passes behind the base of urinary bladder
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Finally, approaches the base of prostate and
joins with the duct of seminal vesicle to form the ejaculatory duct
Seminal
vesicle
• They are paired, elongated and highly folded
tubular glands
• It secrete a fluid rich in fructose which is
the principal metabolic substrate for sperm
• It is lined by pseudostratified columnar
epithelium which contain tall, nonciliated columnar cells and short, rounded
cells that rest on basal lamina
Prostate
gland
•
This is a pyramidal-shaped, fibromuscular and
glandular organ 3cm in long, which surrounds the prostatic urethra
Prostate gland: relations
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Superiorly: it is continuous with the neck of
urinary bladder
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Inferiorly, the apex of the prostate rest on
external sphincter of the bladder
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Anteriorly, lies the pubic symphysis separated
by the extraperitoneal fat of retropubic space
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Posteriorly,lies the rectum separated by the
fascia of Denonvilliers
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Laterally, lies levator ani
The prostatic capsules
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These are normally two
•
The true capsule – a thin fibrous sheath
which surrounds the gland
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The false capsule –condensed
extraperitoneal fascia
• Between
layers 1 and 2 lies the prostatic venous plexus
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In
prostatic operation the true capsule is not disturbed because the prostatic
venous plexus lying external to this.
The prostate gland
secretes prostatic acid phosphatase (PAP), fibrinolysin, citric acid &
prostate specific antigen
Presenting parts of
prostate
•
The apex
is directed below
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The base
is directed above and surrounds the neck of the bladder. It is pierced by the
urethra in the median plane
•
Anterior
surface is narrow and convex situated behind the lower part of symphysis pubis
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Each
infero-lateral surface is related to the anterior fibers of the levator ani
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The
posterior surface is broad and flat related to the ampulla of rectum. This
surface is palpable by rectal examination about 4 cm.above the anus.
The penis
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It forms
the male organ of copulation and consists of two parts – a root and a body
•
The root
is situated in the superficial perineal pouch and consists of two diverging
crura and a median bulb of the penis
The body of the
penis the body of the penis consists principally of two dorsal
masses of erectile tissue the corpora cavernosa which are the continuation of
two crura and a ventral mass of erectile tissue the corpora spongiosum, in which
the spongy part of urethra is embedded and it is the continuation of bulb of
penis .
CORPORA CAVERNOSA
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It is
divided into number of intercommunicating cavernous spaces which is lined by
endothelium
•
These
spaces receive the blood from the capillaries of the helicine arteries are the
branches of deep artery of penis
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During
erection the arterioles dilate and the cavernous spaces are filled with blood,
at the same time the venous outflow is diminished by the pressure of the
distended cavernous spaces. Therefore, erection is purely a vascular
phenomenon
Coverings
of penis
•
The skin
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The
superficial fascia
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Fibrous
envelope- the tunica albuginea
Ligaments of penis
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Fundiform
ligaments
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Suspensory
ligaments
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Erection
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It is a vascular phenomenon which occur by
the action of parasympathetic nerve. The parasympathetic nerve ( S2-4 spinal
segments) dilate arterioles of the corpora cavernosa
•
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Ejaculation
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It is
stimulated by the sympathetic nerves (L1 spinal segment) which produce
contraction of the vas deferens, seminal vesicle, ejaculatory ducts and
prostate.
•
Contraction
of the internal urethral orifice preventing the reflux of semen into the
bladder
•
At the
end of the ejaculation, the sympathetic
nerves produce vasoconstriction of penis and the penis is flaccid.
The
parasympathetic initiates the sexual act by erection & sympathetic finalizes
the act by ejaculation
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