Male Reproductive System Slides 2003

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Male Reproductive System Slides 2003

• Dr. James May

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1 Testis. This image is a low magnification
through a testis illustrating several
seminiferous tubules cut in cross-section (X).
The seminiferous tubules are embedded in a loose
connective tissue, the interstitium, containing
collagen fibers, loose connective cells, and
Leydig cells. The area encircled in red is
enlarged on the next page.
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2 Leydig Cells. This is a high magnification of
the previous image illustrating Leydig cells
(arrows) located between the seminiferous
tubules. These cells secrete androgens and are
under the influence of Interstitial Cell
Stimulating Hormone (ICSH). Since they are
steroid-producing cells, the cytoplasm often
appears vacuolated.
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3 Seminiferous Tubule. The yellow arrow points
to the interstitium located between the
seminiferous tubules. Lining the outer portion of
the seminiferous tubules are spermatogonia (red
arrows). They give rise to primary spermatocytes
(green arrows). These cells are larger than
spermatogonia and are usually in an extended
meiotic division as evidenced by the presence of
chromosomes. Primary spermatocytes give rise to
secondary spermatocytes (not identified).
Secondary spermatocytes remain as such for very
short period of time and are difficult to
distinguish from the next stage, spermatids
(orange arrows). The spermatids may be found in
various stages of spermiogenesis. Sertoli cells
(black arrows) are roughly columnar in shape and
extend from the outer portion of the wall of the
seminiferous tubule to the luminal surface. The
cytoplasm does not stain well, so identification
is based on their nuclei. Their nuclei are
light-staining and contain a prominent nucleolus.
Sertoli nuclei are usually oval in shape with the
long axis being perpendicular to the rim of the
wall. For purposes of this laboratory, you need
only to identify spermatogonia, primary
spermatocytes, spermatids, spermatozoa (not
illustrated) and Sertoli cells.
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4 Seminiferous Tubule. In this image of
seminiferous tubule, several cell types are
illustrated. The red arrows point to
spermatogonia. The cells encircled in red appear
to be spermatogonia in mitosis. The cells
encircled in green are primary spermatocytes. The
cells encircled in black are examples of
spermatids. A small blood vessel is shown in the
interstitium (green arrow) along with a Leydig
cell (black arrow).
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5 Seminiferous Tubule. This is another image of
the wall of the seminiferous tubule illustrating
several cell types Sertoli cells (black arrows),
spermatogonia (red arrows), primary spermatocytes
(green arrows) and spermatids (encircled in
black). By convention, spermatozoa are not
identified as such until they are released into
the lumen as a result of the apical degeneration
of the Sertoli cells.
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6 Seminiferous Tubule. This is another image of
the wall of the seminiferous tubule illustrating
several cell types Can you identify the
spermatogonia, primary spermatocytes, and the
spermatids?? The cells encircled in black are
spermatids in the late stages of spermiogenesis.
A few nuclei of spermatozoa (red arrows) can be
identified in the lumen of the tubule.
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7 Straight Tubules (tubuli recti). This is
section through several straight tubules. The
seminiferous tubules from each lobule join to
form a single straight tubule. All of the
straight tubules empty into the rete testis
located in the mediastinum testis. Straight
tubules are lined entirely by Sertoli cells.
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8 Straight Tubules (tubuli recti). This is
another image illustrating portions of two
straight tubules (S.T.) lined by Sertoli cells. A
portion of a seminiferous tubules is shown on the
right.
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9 Rete Testes. This is a section through the
mediastinum testes (encircles in black)
illustrating the rete testes (black arrows). The
mediastinum testes contains a dense connective
tissue (red arrows) and is the posterior
extension of the tunica albuginea. The rete
testes is a an extensive labyrinth of
anastomosing, very irregular channels that
receive the contents of the straight tubules.
Rete are lined by a simple cuboidal epithelium.
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10 Rete Testes. This is a higher magnification of
the previous image illustrating the rete testes.
The red arrows point to the simple cuboidal
epithelial lining.
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11 Efferent Ducts. 8-15 efferent ducts
transport the spermatozoa from the rete testes to
the epididymus located on the posterior aspect of
the testes. The epithelial lining contains groups
of simple cuboidal cells alternating with groups
of simple columnar cells. Some of the cells
contain cilia. These ciliated cells are the only
motile lining cells in the entire duct system.
The efferent ducts form the head of the
epididymus. The ductus epididymus empties into
the ductus (vas) deferens.
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12 Epididymus. The efferent ducts collect and
join as a single, highly coiled ductus
epididymus, measuring 5-7- meters in length. The
ductus epididymus forms the body and the tail of
the epididymus. What forms the head?? This duct
is lined by a pseudostratified columnar
epithelium. The columnar cells contain
stereocilia that increase the surface area for
absorption, i.e., spermatozoa are concentrated
in this portion of the duct system. Spermatozoa
are stored in the tail portion of the epididymus
until ejaculation.
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13 Epididymus. This is a higher magnification of
the ductus epididymus illustrating the tall
epithelial cells containing stereocilia. There is
a thin layer of circularly arranged smooth muscle
cells around the outer part of the tubule. The
entire epididymus is covered with dense
connective tissue containing smooth muscle cells.
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14 Epididymus. This is high magnification of the
previous image illustrating a portion of the
ductus epididymus. Note the stereocilia. What is
their function? The lumen contains spermatozoa.
Connective tissue with smooth muscle cells are
present outside the tubule
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15 Seminal Vesicle. Each seminal vesicle is a
tortuous elongated diverticulum off of the ductus
deferens just posterior to the prostate gland.
The wall of the seminal vesicle contains
circularly and longitudinally arranged smooth
muscle cells. The mucosa contains tall folds that
branch into secondary and tertiary folds (right
image-encircled in red and yellow). Many of the
folds merge with one another to form
compartments. The epithelial lining is usually
pseudostratified columnar.
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15 (cont.) Seminal Vesicle. Each seminal vesicle
is a tortuous elongated diverticulum off of the
ductus deferens just posterior to the prostate
gland. The wall of the seminal vesicle contains
circularly and longitudinally arranged smooth
muscle cells. The mucosa contains tall folds that
branch into secondary and tertiary folds (right
image-encircled in red and yellow). Many of the
folds merge with one another to form
compartments. The epithelial lining is usually
pseudostratified columnar.
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16 Seminal Vesicle. This is high magnification of
the previous image. Note the compartmentalization
of the mucosa as a result of the merging of the
mucosal folds. Note also the thick wall of the
gland containing lots of smooth muscle.
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17 Prostate Gland. The prostate gland surrounds
the urethra at its origin. It consists of an
aggregate about 30-50 compound tubuloavleolar
glands embedded in a dense fibromuscular stroma
containing lots of smooth muscle. The black
arrows point to the lumen of the glands. The
lumen of many of the glands contain prostatic
concretions or corpora amylacea (red arrows),
especially in older men.. The concretions are
usually of varied size and shape. They are
believed to be formed by precipitation of
secretory material and may calcify.
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18 Prostate Gland. This is high magnification of
a portion of a prostatic gland showing the thick
fibromuscular wall containing smooth muscle. The
mucosa contains epithelium that varies from
simple cuboidal to simple columnar depending upon
the activity level of the gland. Two prostatic
concretions are present (arrows).
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19 Penis. This is high magnification of a
cross-section of penis. The corpora cavernosa
(CC) are enveloped in a dense connective tissue,
the tunica albuginea (TA). The corpus spongiousum
(CS) is illustrated with the urethra (U) in the
center.