Reproduction Histo Lab

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Reproduction Histo Lab

• Male Reproduction Lab

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• This laboratory is concerned with the
  identification of the histological features of
  the male reproductive system. It includes a study
  of the following components Testes, Efferent
  Ducts, Epididymus, Seminal Vesicle, Prostate
  Gland and Penis..Be able to distinguish each of
  these structures and their salient features.

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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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.
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FEMALE REPRODUCTION LABORATORY

• This laboratory is concerned with the
  identification of the histological features of
  the female reproductive system. It includes a
  study of the following components Ovaries,
  containing follicles in different stages of
  development, Uterine tubes, Uterine Endometrium,
  and Placenta. Be able to distinguish each of
  these structures and their salient features.

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Ovary. This image is section through the cortical
region of an ovary. It is lined by germinal
epithelium (black arrows) which contains cuboidal
cells. The tunica albuginea (red arrow) is a
dense connective tissue layer lying deep to the
germinal epithelium. Deep to the tunica albuginea
is a small collection of primordial follicles
(green arrows).
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Primordial Follicles. This image is a higher
magnification of the previous image illustrating
a group of primordial follicles (arrows).
Primordial follicles contain primary oocytes
surrounded by a single layer of squamous
"follicular" cells.
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Primary Follicle. The first sign of follicular
development is the enlargement of the squamous
cells (surrounding the primary oocyte) into
cuboidal cells. A primary oocyte surrounded by a
single layer of cuboidal cells is classified as a
Primary Follicle. The development of a Zona
Pellucida (arrow) is evident in the micrograph.
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Multilaminar Primary Follicle. As a result of
continued stimulation by FSH, the follicular
cells undergo mitotic activity and form multiple
layers of cells. Such a follicle is now
classified as a Multilaminar Primary Follicle
(arrow). The development of the theca folliculi
is also evident at this stage.
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Multilaminar Primary Follicle. This is a higher
magnification of a multilaminar primary follicle.
This follicle is characterized as having a
primary oocyte surrounded by several layers of
follicular cells. A zona pellucida (red arrow)
separates the follicular cells from the primary
oocyte. The black arrow points to the developing
theca folliculi.
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Secondary Follicle. As the follicles increase in
size, small pools of fluid (arrows) accumulate
among the granulosa (follicular) cells
characterizing Secondary Follicles. These small
pools will eventually coalesce into a single pool
called an antrum. The black arrow points to the
theca folliculi. The area in yellow is enlarged
on the next page.
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Theca Folliculi. This is a higher magnification
of a section of the tissue illustrated on the
previous page. The black line shows the
separation of the granulosa cells (G) and the
theca folliculi. At this magnification the theca
externa (red arrow) can be distinguished from the
theca interna (green arrow).
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Mature (Graafian) Follicle. The mature follicle
is characterized as having a single, large antrum
containing "liquor folliculi". The wall of
granulosa cells is thinned.
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Mature (Graafian) Follicle. The green arrow
points to the thin wall of granulosa cells. The
red arrow points to the cytoplasm of the primary
oocyte. Several granulosa cells are clustered
between the wall of the follicle and the primary
oocyte to form a "pedestal" or Cumulus Oophorus
(black arrow). The cells forming the cumulus
oophorus will eventually dissociate, freeing the
oocyte and its surrounding cell population into
the antrum in preparation for ovulation.
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Mature (Graafian) Follicle. This is a higher
magnification of the previous image. The red
arrow points to the cytoplasm of the primary
oocyte. The row of granulosa cells surrounding
the zona pellucida has enlarged into columnar
cells known as the Corona Radiata (black arrow).
The blue arrow points to the cumulus oophorus.
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Mature (Graafian) Follicle. Each ovarian follicle
contains a primary oocyte that is arrested in the
prophase of the first meiotic division. Near the
time of ovulation, the primary oocyte continues
the first meiotic division. This image
illustrates a primary oocyte in the metaphase
stage of the first meiotic division (black
arrow). The daughter cells will be the a
secondary oocyte and the first polar body. The
granulosa cells are encircled in black and the
theca interna and externa are encircled in green.
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Mature (Graafian) Follicle. This is a higher
magnification of the previous image illustrating
a primary oocyte in metaphase of the first
meiotic division. The daughter cells will be the
a secondary oocyte and the first polar body.
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Corpus Luteum. Following ovulation and still
under the influence of LH, the cells of the
ovulated follicle "restructure" to form the
Corpus Luteum. As a result of hypertrophy and
hyperplasia, the corpus luteum is much larger
than the original follicle. The granulosa cells
become the Granulosa Lutein cells (G) which
occupy the bulk of the organ and are centrally
located. The cells of the theca interna become
the Theca Lutein (yellow arrows) and occupy the
periphery of the corpus luteum. These cells are
smaller than those of the granulosa lutein thus
the nuclei are closer together and appear
somewhat darker.
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Corpus Luteum. This is a higher magnification of
the previous image illustrating the cells of the
granulosa lutein which takes up most of the
image. The cells of the theca lutein are
encircled in red.
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Corpus Albicans. Each of the images illustrates a
Corpus Albicans indicated by large amounts of
collagen. As the corpus luteum degenerates,
macrophages and fibroblast invade this area
connective tissue replaces the degenerated debris
that was phagocytized by the macrophages. In
time, the corpus albicans becomes reduced in
size.
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Uterine Tube. This is a section through the
ampulla of the uterine tube. This area of the
tube contains a mucosa (yellow arrows) that is
highly folded. Some of the mucosal folds are
branched. The epithelium is simple columnar (next
page).
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Uterine Tube. These images are of a high
magnification of the previous image illustrating
the simple columnar lining of the ampulla mucosa.
Note that some of the cells contain cilia (black
arrows) while others are secretory in nature.
Deep to the epithelium is a highly cellular loose
connective tissue (the lamina propria green
arrows) containing blood vessels (red arrows).
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Uterine Mucosa. These images are of a high
magnification of the uterine mucosa illustrating
the simple columnar epithelial lining. Note that
some of the cells contain cilia (black arrows)
while others are secretory in nature( blue
arrows.
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Endometrium. This image is a section through the
endometrium of the uterus in the proliferative
(follicular, estrogenic) phase of the menstrual
cycle. The lumen of the uterus is to the right.
The black line indicates the approximate division
of the endometrium from the underlying
myometrium. The luminal portion of the
endometrium is called stratum functionalis while
the deeper portion is referred to as stratum
basalis, which tends to have a somewhat darker
staining appearance. The red line indicates the
approximate division between the two strata. The
wavy clear spaces are the uterine glands (red
arrows). The stratum functionalis, which sloughs
during menstruation, is in the process of
regenerating during this proliferative period
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Endometrium. This image is a section through the
endometrium of the uterus in the secretory
(luteal, progestational) phase of the menstrual
cycle. In this phase, the endometrium is being
prepared to receive a developing embryo. The
lumen of the uterus is to the right. Note that in
this phase of the menstrual cycle that glands are
much elongated to the surface. They become
tortuous in appearance and begin their secretory
activity.
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Placenta. This section through the placenta
illustrating several secondary placental villi
(yellow arrows). Secondary villi are
characterized as having a core of mesoderm
developing into a loose connective tissue. The
villi are lined by Syncytiotrophoblast cells.
Cytotrophoblast cells are found just deep to
these cells. (see next page)
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Placenta. This is a higher magnification of the
previous image illustrating secondary placental
villi. Note that the core contains mesoderm
developing into a loose connective tissue. It is
lined by two sets of cells syncytiotrophoblast
(S) and cytotrophoblast (C) see inset.
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Placenta. This is a low magnification section
through the placenta illustrating several
tertiary villi (yellow arrows). These villi now
contain the embryos capillaries embedded in a
loose connective tissue. The intervillous spaces
now contain the maternal blood (green arrows).
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Placenta. This is a higher magnification section
through the placenta illustrating several
tertiary villi. The red arrows point to the fetal
capillaries. The green arrows point to the
maternal blood.
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Placenta. This is yet a higher magnification
section through the placenta illustrating
tertiary villi. The red arrows are pointing to
the fetal blood within the villi, the green
arrows to the maternal blood in the intervillus
space. The villi are lined by syncytiotrophoblast
(blue arrows). In the older villi, the
cytotrophoblast cells are sparse (black arrow).
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