Chapter Fifteen: Male Reproductive System
Introduction
The male reproductive system is responsible for: 1) production, maturation,
storage, and transport of the male gamete (spermatogenesis), and 2) synthesis and
controlled release of steroid hormones (steroidogenesis). In this lab you will be studying
the microscopic anatomy of many components of the male reproductive system,
including the testis, the excurrent duct system, a series of accessory exocrine glands that
produce much of the seminal volume, and the penis.
Prior to learning the microarchitecture of Male Reproductive System, use the table below to review some of the gross anatomy of these tissues:
Structure |
Image |
Fascial Layers Surrounding the Testis |
|
Gross Anatomical Location of the Testis |
|
Cross Section of the Testis |
|
The Ducts of the Male Reproductive System |
|
The Prostate and Seminal Vesicle |
|
Orientation of the Male Urogenital Tract |
|
The Penis |
|
Cross Section of the Penis |
|
Top of page
Testis
Scan a section of testis from the slide boxes at low magnification, and note the
arrangement of the testicular components (slide B-80, H&E [
1x-labeled,
1x,
1x]; B-81,
PAS [
1x,
1x]; B-82, adult monkey testis, H&E [
1x,
1x,
1x,
1x,
1x] [
2.5x,
10x]). A thick
fibroelastic connective tissue capsule, or tunica albuginea, surrounds the testis. Within
the tunica and sometimes bulging inward are a number of large blood vessels. The larger,
thicker walled vascular profiles are sections through the testicular artery, which executes
a highly convoluted course through the tunical plane. Closely applied to
the outer surface of the tunica albuginea is the visceral layer of the tunica vaginalis,
whose free surface is lined with mesothelium (B-81, PAS [
2.5x-labeled]). In some
specimens the parietal layer of the tunica vaginalis has been removed, but in others it is
possible to find both layers of the tunica vaginalis and the potential serous space between
them. How does the tunica vaginalis originate? Connective tissue septa extend inward
from the tunica albuginea, subdividing the testis into a number of lobules. Within each
lobule are numerous profiles of seminiferous tubules (B-82 [
2.5x-labeled,
10x] [
20x,
40x]). The interstitial space
between the seminiferous tubules is occupied by a loose connective tissue matrix that is
permeated by blood and lymphatic vessels and contains clusters of Leydig cells
(interstitial cells) (B-82 [
40x-labeled]).
Both androgens and spermatozoa are produced by the testis. Androgen synthesis
is accomplished by Leydig cells. Leydig cells are often arranged in clusters with their
distinct nuclei displaying a prominent nucleolus (B-82 [
2.5x,
10x,
20x-labeled,
40x-labeled]).
These clusters are located in close proximity to small blood vessels or
elements of the extensively developed testicular lymphatic system. What might this relationship
facilitate? The abundant eosinophilic cytoplasm usually has vacuolated appearance.
Observe the interstices at high magnification in slide B-80 (H&E [
2.5x,
10x,
20x,
40x-labeled] [
10x,
20x,
40x]).
Be aware, however, that most of the empty-appearing interstitial spaces in these slides are
artifacts of specimen preparation.
Sperm production, or spermatogenesis, encompasses two distinct series of events:
one affecting mostly the nucleus, the other affecting mostly the cytoplasm. First, there is
a series of events, known collectively as spermatocytogenesis, in which rounded diploid
stem cells (spermatagonia) give rise to clusters of rounded haploid cells (spermatids).
Then there is a series of events, known collectively as spermiogenesis, in which the round
spermatid spins a long flagellum, undergoes compaction of its nucleus, transforms its
Golgi complex into an acrosomal cap, and sheds nearly all of its cytoplasm to yield a
spermatazoa. Bear in mind that if you are to develop a good sense of the dynamics of
sperm production, you will have to examine a number of seminiferous tubules. This is
because spermatogenesis is typified by complex waves of proliferation and differentiation
that sweep both around the circumference and along the length of the seminiferous
tubule. Using the high dry objective, search slide B-81 for a transversely sectioned
seminiferous tubule (i.e. one that presents a round profile in which a large lumen is
surrounded by an epithelial wall of uniform thickness). Observe that the peripheral
surface is demarcated by a continuous layer of small flattened cells containing elongated
basophilic nuclei. These are contractile myoid cells (similar to the myoepithelial cells of
other glands), which aid in propulsion of the luminal contents towards the excurrent duct
system (B-81, testis, PAS [
2.5x-labeled,
10x,
20x.
40x-labeled]; [
10x,
20x,
40x]).
The clearly stratified seminiferous epithelium differs in appearance from one
tubular profile to another and even from one part of a single tubule to another. The
seminiferous epithelium is composed of two populations of cells: proliferating cells of the
germinal spermatogenic series and nonproliferating Sertoli cells. Sperm production
begins with mitotic division of cells located at the tubule periphery; later events occur
progressively closer to the lumen. In typical H&E preparations of seminiferous
epithelium it is the distinctive qualities of nuclei that stand out against poorly defined
cytoplasm (B-80, testis, H&E [
20x,
40x-labeled] [
10x,
20x,
40x-labeled] [
10x,
20x,
40x] [
2.5x,
10x,
20x,
40x];
B-82, testis, H&E [
2.5x,
10x,
20x,
40x] [
2.5x,
10x,
20x,
40x] [
10x,
20x,
40x] [
10x,
20x,
40x]). Thus, in your
study of seminiferous epithelium, it is nuclear appearance that will enable you to
distinguish the following cell types:
Top of page
Spermatogonia
Spermatagonia are stem cells that divide mitotically both to maintain the germ
cell line (i.e., to produce more spermatagonia) and to yield primary spermatocytes.
Although some authors identify three or more different types of spermatagonia, you are
not expected to draw such distinctions. You should, however, be able to distinguish
between spermatagonia and their neighbors. Spermatagonia are located at the periphery
(i.e., in the basal portion) of the seminiferous epithelium. Their nuclei are generally
spherical or ovoid, show variable intensity of staining and may or may not have a
discernible nucleolus.
Primary Spermatocytes
Primary spermatocytes originate from mitotic division of spermatogonia and are
usually one or more cell diameters removed from the tubular periphery. Their nuclei are
more or less spherical and are conspicuously larger than those of other germ cells; their
chromatin is usually condensed into many thread-like structures. Most primary
spermatocytes are seen in some stage of the very protracted (21-day) prophase leading up
to the first meiotic (reduction) division, in which each primary spermatocyte gives rise to
two secondary spermatocytes.
Secondary Spermatocytes
Within about 8 hours of its own generation, each secondary spermatocyte
completes the second meiotic (equatorial) division to yield two spermatids. Because they
are so short-lived, secondary spermatocytes are often difficult to find. When present,
they are located toward lumen from primary spermatocytes. They are about 2/3 the
diameter of primary spermatocytes and about 1/3 greater in diameter than recently
generated, spherical spermatids.
Spermatids
Spermatids are located next to lumen of the seminiferous tubule, where they
undergo an elaborate differentiation process (spermiogenesis) that requires about 7 weeks
and involves condensation of nuclear chromatin, compaction and elongation of the
nucleus, shedding of nearly all cytoplasm and formation of a motile flagellum (tail).
Spermatid nuclei vary in size, condensation of chromatin and shape according to the
stage of spermiogenesis that they represent; however, all of them are smaller than the
nuclei of any of the antecedent cell types. Spermatids at different stages of
spermiogenesis may be present in a single tubule.
Top of page
Sertoli cells
Interspersed among the germ cells, but generally situated near the epithelial
periphery, are nuclei of the Sertoli cells. Sertoli cells span the full thickness of the
seminiferous epithelium; however, because of their irregular shape and poor affinity for
dyes, it is impossible to define the cytoplasmic processes of Sertoli cells in ordinary
paraffin sections. Sertoli cells have large euchromatic nuclei and very prominent nucleoli.
The nuclear shape is usually oval or triangular, but may also be irregular due to deep
indentations of the nuclear membrane. The long axis of the nucleus is typically oriented
at right angles to the basement membrane. From ultrastructural studies it is known that
Sertoli cell processes make specialized contacts with germ cells as well as with processes
of other Sertoli cells. Sertoli cells are the basis of the blood-testis barrier
As you might expect, there are marked differences between the prepubertal and
postpubertal testis. In the true prepubertal male (slide B-86, epididymis and testis, H&E
[
2.5x,
10x,
20x,
40x]) and in undescended testes of older males, the seminiferous tubules are solid cords of cells, consisting of spermatogonia-like cells known as gonocytes, and
cells that resemble the Sertoli cells of the adult testis.
Section B-78 is from the testis of an older individual and a lumen is now present (B-78, H&E [
2.5x,
10x,
20x,
40x]).
Even though the seminiferous epithelium of this autopsy specimen is poorly preserved,
you should be able to evaluate its spermatogenic capacity. Can you identify
spermatogonia and Sertoli cells? Are spermatids present? Judging from the interstitial
morphology, would you expect high peripheral testosterone levels?
Beginning in the 6th decade, spermatogenesis gradually decreases. A late stage
in testicular aging appears on slide B-79 (senile testis, H&E [
10x,
20x,
40x] [
10x,
20x,
40x]). How many of the germ cell stages can you identify? This specimen also provides
many examples of thickening of the seminiferous tubular wall. Once initiated, this
process apparently continues until the germinal and Sertoli cells are eliminated and the
tubule is a solid cord of connective tissue cells. Such tubules are called hyalinized and
often appear in clusters. Using the scanning or low power objective, locate several
hyalinized seminiferous tubules; then study them under the high-dry objective to confirm
the absence of germ cells.
Testis Image Gallery
Testis Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Cauda (tail of) Epididymis |
(none) |
H&E |
B80, Testis, 1x |
|
2 |
Corpus (body of) Epididymis |
(none) |
H&E |
B80, Testis, 1x |
|
3 |
Tunica Vaginalis |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x |
|
4 |
Tunica Albuginea |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x |
|
5 |
Seminiferous Tubules |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x |
|
6 |
Epididymis |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x |
|
7 |
Septa |
S |
H&E |
B82, Testis, 2.5x |
|
8 |
Blood Vessel |
BV |
H&E |
B82, Testis, 20x |
|
9 |
Leydig (Interstitial) Cells |
LC |
H&E |
B82, Testis, 20x; B81, Testis, 40x |
|
10 |
Connective Tissue Septa |
CT |
H&E |
B82, Testis, 20x |
|
11 |
Seminiferous Epithelium |
SE |
H&E |
B82, Testis, 40x; B81, Testis, 40x |
|
12 |
Lamina Propria |
LP |
H&E |
B82, Testis, 40x |
|
13 |
Myoid Cell |
MC |
H&E |
B82, Testis, 40x; B81, Testis, 40x |
|
14 |
Fibroblast |
F |
H&E |
B82, Testis, 40x |
|
15 |
Endothelial Cell |
En |
H&E |
B80, Testis, 40x |
|
16 |
Spermatocytes |
Sc |
H&E |
B80, Testis, 40x |
|
17 |
Spermatids |
Sp |
H&E |
B80, Testis, 40x |
|
18 |
Sertoli Nuclei |
Sn |
H&E |
B80, Testis, 40x |
|
19 |
Spermatogonia |
Sg |
H&E |
B80, Testis, 40x |
|
Top of page
Excurrent Ducts
Spermiogenesis is concluded when immature (non-motile) spermatozoa detach
from the Sertoli cells and lie free in the lumen of the seminiferous tubule. In the course of
their passage through the intratesticular ducts and the ductus epididymis, sperm acquire
motility and become fully capable of fertilization. This maturation process requires the
presence of androgens as well as glycoprotein secretions of cells that line the excurrent
ducts--especially the epididymis. Three mechanisms account for the movement of newly
released sperm from the seminiferous tubule into and through the excurrent duct
system: (1) contraction of myoid cells, (2) propulsion by ciliated cells in some portions
of the duct system and (3) a physical current produced by net secretion of fluid
proximally and net resorption of fluid distally. In proximodistal sequence, the excurrent
duct system consists of the following regions: rete testis, ductuli efferentes, epididymis,
vas deferens, urethra.
Top of page
Rete testis
The rete testis is an anastomosing network of irregular, epithelium-lined spaces
located in the mediastinum testis. The mediastinum testis is an inward extension of the
tunica albuginea located on the posterior aspect of the testis. Just before it joins the rete
testis, each end of the seminiferous tubule tapers and its epithelial lining consists entirely
of Sertoli cells. These tapered, germ cell-free tubules are known as tubuli recti, or
straight tubules (B-79, H&E [
10x,
20x-labeled,
40x]; B-81, PAS [
10x,
20x,
40x]).
Locate the rete spaces, deep to the tunica albuginea, at one pole of the testicular section.
Note that the epithelium lining these spaces varies from cuboidal to squamous (slide B-
79, H&E [
2.5x-labeled,
10x-labeled,
20x,
40x] [
2.5x-labeled,
10x,
20x,
40x]).
Rete Testis Image Gallery
Rete Testis Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Straight Tubules |
ST |
H&E |
B79, Straight Tubules, 20x |
|
2 |
Sertoli Cells |
SC |
H&E |
B79, Straight Tubules, 20x |
|
3 |
Simple Cuboidal Epithelium (of Rete Testis) |
SCE |
H&E |
B79, Straight Tubules, 20x |
|
4 |
Tunica Albuginea |
TA |
H&E |
B79, Rete Testis, 2.5x |
|
5 |
Rete Testis |
RT |
H&E |
B79, Rete Testis, 2.5x |
|
6 |
Seminiferous Tubules |
ST |
H&E |
B79, Rete Testis, 2.5x |
|
7 |
Vein |
V |
H&E |
B79, Rete Testis, 10x |
|
Top of page
Ductuli efferentes (efferent ductules)
The rete testis is linked to the epididymis by 12 or more highly convoluted ductuli
efferentes. A pseudostratified columnar epithelium of variable thickness lines these
structures. In addition to basal cells, the epithelium exhibits a patchy arrangement of tall
columnar ciliated cells and low columnar or cuboidal cells with brush borders. You
should be able to find a thin layer of circularly arranged smooth muscle cells in the tubule
wall. Ductuli efferentes are classically described as having a scalloped appearance (i.e.
when cut in cross section, the hight of the epithelium varies circumferencially). This
scalloped appearance may be difficult to identify in your slide set (B-81, PAS [
2.5x-labeled,
10x,
20x-labeled,
40x] [
2.5x,
10x-labeled,
20x,
40x] [
10x,
20x,
40x]).
Efferent Duct Image Gallery
Efferent Duct Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Seminiferous Tubules |
ST |
PAS |
B81, Efferent Ducts, 2.5x |
|
2 |
Rete Testis |
RT |
PAS |
B81, Efferent Ducts, 2.5x |
|
3 |
Efferent Ductules |
ED |
PAS |
B81, Efferent Ducts, 2.5x |
|
4 |
Epididymis |
Epi |
PAS |
B81, Efferent Ducts, 2.5x |
|
5 |
Tunica Albuginea |
TA |
PAS |
B81, Efferent Ducts, 2.5x |
|
6 |
Adipose Tissue |
AT |
PAS |
B81, Efferent Ducts, 2.5x |
|
7 |
Tunica Vaginalis |
TV |
PAS |
B81, Efferent Ducts, 2.5x |
|
8 |
Smooth Muscle |
SM |
PAS |
B81, Efferent Ducts, 20x |
|
9 |
Connective Tissue |
CT |
PAS |
B81, Efferent Ducts, 20x |
|
10 |
Blood Vessels |
BV |
PAS |
B81, Efferent Ducts, 20x |
|
11 |
Vein |
(none) |
PAS |
B81, Efferent Ducts, 10x |
|
Top of page
Epididymis
The epididymis is an organ that is composed of the efferent ductules and the
epididymal duct. The epididymal duct consists of a single highly coiled tube that is
closely applied to the posterior aspect of the testis. Locate areas of epididymal tissue at
the periphery of the testis (slide B-80, H&E [
2.5x,
10x,
20x,
40x-labeled] [
10x,
20x,
40x]; B-81, PAS [
2.5x,
10x,
20x,
40x-labeled] [
2.5x,
10x,
20x,
40x-labeled] [
2.5x,
10x,
20x,
40x]; B-82, H&E [
2.5x,
10x,
20x,
40x]). A pseudostratified columnar epithelium that bears long tufts of microvilli, misleadingly called stereocilia, lines the entire length of the epididymal
duct. The epithelium is exceptionally tall in the head of the epididymis (B-80 [
2.5x,
10x,
20x,
40x] [
10x,
20x,
40x] [
2.5x,
10x,
20x,
40x]) and becomes progressively shorter (B-80 [
10x,
20x,
40x]) towards the
distal end of the duct (B-80 [
2.5x] [
2.5x,
10x,
20x,
40x]). As you
study the epithelium, you should identify principal cells, with their prominent tufts of
stereocilia, and basal cells. You should also be able to find occasional lymphocytes
(sometimes called "halo" cells) that are migrating through the epithelium. By studying a
number of different profiles of epididymal duct, you should find that both the principal
cells and the stereocilia are only about half as tall in the tail of the epididymis as they are
in its head. Study the muscular layers of the wall of the epididymis. The most proximal
portion of the epididymis has a single layer of circularly arranged smooth muscle; in the
intermediate segment an outer longitudinal layer of muscle is added; in the distal portion
(tail) an inner longitudinal muscle layer is added. You should be able to find profiles of
epididymal duct with muscular layers of conspicuously different thickness; however, it is
unlikely that you will be able to find profiles with one, two and three muscle layers in the
same section.
Epididymis Image Gallery
Epididymis Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Stereocilia |
SC |
H&E |
B80, Epididymis, 40x |
|
2 |
Slumped Spermatozoa |
S |
H&E |
B80, Epididymis, 40x |
|
3 |
Smooth Muscle |
SM |
H&E |
B80, Epididymis, 40x |
|
4 |
Lymphocyte |
L |
H&E |
B80, Epididymis, 40x |
|
5 |
Blood Vessel |
BV |
H&E |
B80, Epididymis, 40x |
|
6 |
Basal Cells |
BC |
PAS |
B81, Epididymis, 40x |
|
7 |
Principal Cells |
PC |
PAS |
B81, Epididymis, 40x |
|
8 |
Microvilli (Brush Border) |
M |
PAS |
B81, Epididymis, 40x |
|
9 |
Pseudostratified Columnar Epithelium |
PCE |
PAS |
B81, Epididymis, 40x |
|
Top of page
Vas Deferens (ductus deferens)
Locate the ductus deferens in section B-83 (spermatic cord, H&E [
2.5x,
10x-labeled,
20x,
40x] [
20x,
40x] [
10x,
20x,
40x-labeled]). Avoid confusing it with the testicular artery. The duct is a thick, muscular tube lined by a pseudostratified epithelium of varying height, some of the cells
of which may bear stereocilia. Examine the muscular coat. Can you distinguish muscle
fiber groups in different orientations? Why is such a prominent muscular coat necessary?
From the ductus deferens, sperm pass into the prostatic and penile urethrae. At
ejaculation, viscid secretions from the prostate and seminal vesicles are added to the
sperm to form semen.
Vas Deferens Image Gallery
Vas Deferens Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Longitudinal Muscle |
LM |
H&E |
B83, Vas Deferens, 10x |
|
2 |
Circular Muscle |
CM |
H&E |
B83, Vas Deferens, 10x |
|
3 |
Smooth Muscle |
SM |
H&E |
B83, Vas Deferens, 40x |
|
4 |
Pseudostratified Epithelium |
PSE |
H&E |
B83, Vas Deferens, 40x |
|
5 |
Stereocilia |
SC |
H&E |
B83, Vas Deferens, 40x |
|
Top of page
Accessory Glands
Seminal Vesicle
The seminal vesicles originate as diverticula of the ductuli deferentia. The duct of
each seminal vesicle joins the associated ductus deferens a short distance before the latter
empties into the prostatic urethra. With the scanning objective, note that the seminal
vesicle appears to consist of several thick walled tubules lined with a secretory
epithelium. Although the luminal lining is thrown into many folds and often appears
cavitated, the cavities are not tubular glands, but freely connect with the central lumen.
The epithelium, which rests on a vascular lamina propria, varies from low columnar to
pseudostratified. The outer wall of the seminal vesicle is made up largely of an inner
circular and an outer longitudinal layer of smooth muscle (slide B-89, H&E [
2.5x,
10x-labeled,
20x,
40x] [
2.5x,
10x,
20x,
40x-labeled] [
2.5x,
10x-labeled,
20x,
40x]).
Seminal Vesicle Image Gallery
Seminal Vesicle Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Smooth Muscle |
(none) |
H&E |
B89, Seminal Vesicle, 10x |
|
2 |
Lumen |
(none) |
H&E |
B89, Seminal Vesicle, 10x; B89, Seminal Vesicle, 40x |
|
3 |
Mucosal Folds |
(none) |
H&E |
B89, Seminal Vesicle, 10x |
|
4 |
Epithelium (Pseudostratified) |
Ep |
H&E |
B89, Seminal Vesicle, 40x |
|
5 |
Basal Cells |
BC |
H&E |
B89, Seminal Vesicle, 40x |
|
6 |
Lamina Propria |
LP |
H&E |
B89, Seminal Vesicle, 40x |
|
Top of page
Prostate Gland
The prostate is an aggregate of numerous tubulo-alveolar glands embedded in a
dense stroma of collagen fibers and smooth muscle (B-90 [
2.5x,
10x,
20x,
40x-labeled];
B-91 [
2.5x,
10x, [[http://www.medicalhistology.us/wiki/bin/viewfile/Main/ProstateImages?rev=1;filename=b91_prostate_adult_20x_he.jpg[20x]],
40x-labeled] [
2.5x,
10x,
10x,
20x,
40x]). Note that the prostatic urethra, the portion of the urethra which runs through the prostate gland, is also present (B-91 [
2.5x,
10x,
20x,
40x]). Under high dry magnification, it is obvious that the glandular epithelium varies from simple cuboidal to pseudostratified columnar. Prostatic acini often contain
eosinophilic corpora amalacea (prostatic concretions) (B-90 [
2.5x,
10x,
20x,
40x-labeled]).
The number and degree of calcification of these spherical, lamellated
structures increase with age. In some sections, the prostatic urethra can be identified.
Functional, as well as morphological, maintenance of the adult prostate and
seminal vesicles depends on adequate levels of circulating testosterone. Examine the
prepubertal prostate (B-92 [
2.5x,
10x,
20x,
40x] [
2.5x-labeled,
10x,
20x,
40x]). How
does this specimen differ from that on slide B-90?
Prostate Image Gallery
Prostate Vesicle Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Smooth Muscle |
(none) |
H&E |
B90, Prostate, 40x |
|
2 |
Dense Connective Tissue |
DCT |
H&E |
B91, Prostate, 40x |
|
3 |
Basal Cells |
BC |
H&E |
B91, Prostate, 40x |
|
4 |
Secretory Cells |
SC |
H&E |
B91, Prostate, 40x |
|
5 |
Epithelium |
Epi |
H&E |
B90, Prostate, 40x |
|
6 |
Lumen |
(none) |
H&E |
B90, Prostate, 40x |
|
7 |
Prostatic Concretion |
(none) |
H&E |
B90, Prostate, 40x |
|
8 |
Prostatic Urethra |
PU |
H&E |
B92, Prostate, 2.5x |
|
9 |
Tubuloalveolar Prostate Glands |
PG |
H&E |
B92, Prostate, 2.5x |
|
Top of page
Penis
Examine the section on slide B-85 with your naked eye. Locate the paired, dorsally situated, corpora
cavernosa penis ([
1x-labeled,
1x] [
1x,
1x,
1x] [
2.5x-labeled,
10x,
20x-labeled,
40x] [
2.5x])
and ventrally situated corpus spongiosum (aka corpus cavernosum urethrae) ([
2.5x-labeled,
10x,
20x-labeled,
40x]), which surrounds the penile (spongy) urethra ([
2.5x,
10x,
20x,
40x]). With
the low power objective, note the dense collagenous connective tissue (tunica albuginea
penis) that surrounds and separates the corpora cavernosa ([
2.5x-labeled]). The corpus
spongiosum is also surrounded by a connective tissue sheath, but its tunic is very much
thinner and contains a greater proportion of elastic fibers than that of the corpora
cavernosa. What is the consequence of the thinner tunica albuginea of the corpus
spongiosum? The median septum between the corpora cavernosa is incomplete distally
so that there is communication between the vascular spaces of these paired structures.
What is the practical consequence of this feature?
The erectile tissue of the penis consists of trabeculae of connective tissue and
smooth muscle, which are covered with endothelium and divide the cavernous bodies
into a sponge-like systems of irregular lacunae (vascular spaces). Overall, the trabeculae
are thinner and the lacunae larger in the corpus cavernosum penis than in the corpus
spongiosum. Look near the center of each corpus cavernosum penis for the deep (or
central) artery of the penis ([
2.5x-labeled,
10x,
20x,
40x] [
40x]). Examine the trabeculae
near the deep artery of the penis in search of small, highly coiled branches of the deep
artery, known as helicine arteries. The helicine arteries open directly into the cavernous
spaces and are notable for a thick tunica intima of longitudinally oriented smooth muscle
fibers which serve to keep the arteries closed when the penis is flaccid. Thin-walled
veins drain the lacunae through the connective sheath.
Penis Image Gallery
Penis Table of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Deep Artery of the Penis |
(none) |
H&E |
B85, Penis, 1x; B85, Penis, 2.5x |
|
2 |
Septum of the Penis |
(none) |
H&E |
B85, Penis, 1x; B85, Penis, 2.5x |
|
3 |
Corpus Cavernosum Penis |
(none) |
H&E |
B85, Penis, 1x; B85, Penis, 2.5x |
|
4 |
Dorsal Artery of the Penis |
(none) |
H&E |
B85, Penis, 1x |
|
5 |
Dorsal Nerve of the Penis |
(none) |
H&E |
B85, Penis, 1x |
|
6 |
Deep Dorsal Vein |
(none) |
H&E |
B85, Penis, 1x |
|
7 |
Superficial Dorsal Vein |
(none) |
H&E |
B85, Penis, 1x |
|
8 |
Tunica Albuginea |
(none) |
H&E |
B85, Penis, 1x |
|
9 |
Deep Fascia |
(none) |
H&E |
B85, Penis, 1x |
|
10 |
Skin |
(none) |
H&E |
B85, Penis, 1x |
|
11 |
Trabeculae (Connective Tissue and Smooth Muscle) |
T |
H&E |
B85, Penis, 20x |
|
12 |
Lacunae (Vascular Space) |
L |
H&E |
B85, Penis, 20x |
|
13 |
Endothelium |
En |
H&E |
B85, Penis, 20x |
|
14 |
Corpus Spongiosum |
CSP |
H&E |
B85, Penis, 2.5x |
|
15 |
Urethra |
U |
H&E |
B85, Penis, 2.5x |
|
Top of page
Chapter Fifteen Review
Review of Slides
Review of Identifications
Row |
Structure |
Abbreviation |
Optimal Stain |
Representative Section |
Note |
1 |
Cauda (tail of) Epididymis |
(none) |
H&E |
B80, Testis, 1x |
|
2 |
Corpus (body of) Epididymis |
(none) |
H&E |
B80, Testis, 1x |
|
3 |
Tunica Vaginalis |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x |
|
4 |
Tunica Albuginea |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x; B79, Rete Testis, 2.5x |
|
5 |
Seminiferous Tubules |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x; B79, Rete Testis, 2.5x |
|
6 |
Epididymis |
(none) |
H&E, PAS |
B80, Testis, 1x; B81, Testis, 2.5x; B81, Efferent Ducts, 2.5x |
|
7 |
Septa |
S |
H&E |
B82, Testis, 2.5x |
|
8 |
Blood Vessel |
BV |
H&E |
B82, Testis, 20x |
|
9 |
Leydig (Interstitial) Cells |
LC |
H&E |
B82, Testis, 20x; B81, Testis, 40x |
|
10 |
Connective Tissue Septa |
CT |
H&E |
B82, Testis, 20x |
|
11 |
Seminiferous Epithelium |
SE |
H&E |
B82, Testis, 40x; B81, Testis, 40x |
|
12 |
Lamina Propria |
LP |
H&E |
B82, Testis, 40x; B89, Seminal Vesicle, 40x |
|
13 |
Myoid Cell |
MC |
H&E |
B82, Testis, 40x; B81, Testis, 40x |
|
14 |
Fibroblast |
F |
H&E |
B82, Testis, 40x |
|
15 |
Endothelial Cell |
En |
H&E |
B80, Testis, 40x |
|
16 |
Spermatocytes |
Sc |
H&E |
B80, Testis, 40x |
|
17 |
Spermatids |
Sp |
H&E |
B80, Testis, 40x |
|
18 |
Sertoli Nuclei |
Sn |
H&E |
B80, Testis, 40x; B79, Straight Tubules, 20x |
|
19 |
Spermatogonia |
Sg |
H&E |
B80, Testis, 40x |
|
20 |
Straight Tubules |
ST |
H&E |
B79, Straight Tubules, 20x |
|
21 |
Simple Cuboidal Epithelium (of Rete Testis) |
SCE |
H&E |
B79, Straight Tubules, 20x |
|
22 |
Rete Testis |
RT |
H&E |
B79, Rete Testis, 2.5x; B81, Efferent Ducts, 2.5x |
|
23 |
Vein |
V |
H&E |
B79, Rete Testis, 10x; B81, Efferent Ducts, 10x |
|
24 |
Efferent Ductules |
ED |
PAS |
B81, Efferent Ducts, 2.5x |
|
25 |
Adipose Tissue |
AT |
PAS |
B81, Efferent Ducts, 2.5x |
|
26 |
Smooth Muscle |
SM, (none) |
PAS, H&E |
B81, Efferent Ducts, 20x; B80, Epididymis, 40x; B83, Vas Deferens, 40x; B89, Seminal Vesicle, 10x; B90, Prostate, 40x |
|
27 |
Connective Tissue |
CT |
PAS |
B81, Efferent Ducts, 20x |
|
28 |
Blood Vessels |
BV |
PAS |
B81, Efferent Ducts, 20x |
|
29 |
Stereocilia |
SC |
H&E |
B80, Epididymis, 40x; B83, Vas Deferens, 40x |
|
30 |
Slumped Spermatozoa |
S |
H&E |
B80, Epididymis, 40x |
|
31 |
Lymphocyte |
L |
H&E |
B80, Epididymis, 40x |
|
32 |
Basal Cells |
BC |
PAS |
B81, Epididymis, 40x; B89, Seminal Vesicle, 40x; B91, Prostate, 40x |
|
33 |
Principal Cells |
PC |
PAS |
B81, Epididymis, 40x |
|
34 |
Microvilli (Brush Border) |
M |
PAS |
B81, Epididymis, 40x |
|
35 |
Pseudostratified Columnar Epithelium |
PCE |
PAS |
B81, Epididymis, 40x |
|
36 |
Longitudinal Muscle |
LM |
H&E |
B83, Vas Deferens, 10x |
|
37 |
Circular Muscle |
CM |
H&E |
B83, Vas Deferens, 10x |
|
38 |
Pseudostratified Epithelium |
PSE, Ep |
H&E |
B83, Vas Deferens, 40x; B89, Seminal Vesicle, 40x |
|
39 |
Lumen |
(none) |
H&E |
B89, Seminal Vesicle, 10x; B89, Seminal Vesicle, 40x; B90, Prostate, 40x |
|
40 |
Mucosal Folds |
(none) |
H&E |
B89, Seminal Vesicle, 10x |
|
41 |
Dense Connective Tissue |
DCT |
H&E |
B91, Prostate, 40x |
|
42 |
Secretory Cells |
SC |
H&E |
B91, Prostate, 40x |
|
43 |
Epithelium |
Epi |
H&E |
B90, Prostate, 40x |
|
44 |
Prostatic Concretion |
(none) |
H&E |
B90, Prostate, 40x |
|
45 |
Prostatic Urethra |
PU |
H&E |
B92, Prostate, 2.5x |
|
46 |
Tubuloalveolar Prostate Glands |
PG |
H&E |
B92, Prostate, 2.5x |
|
47 |
Deep Artery of the Penis |
(none) |
H&E |
B85, Penis, 1x; B85, Penis, 2.5x |
|
48 |
Septum of the Penis |
(none) |
H&E |
B85, Penis, 1x; B85, Penis, 2.5x |
|
49 |
Corpus Cavernosum Penis |
(none) |
H&E |
B85, Penis, 1x; B85, Penis, 2.5x |
|
50 |
Dorsal Artery of the Penis |
(none) |
H&E |
B85, Penis, 1x |
|
51 |
Dorsal Nerve of the Penis |
(none) |
H&E |
B85, Penis, 1x |
|
52 |
Deep Dorsal Vein |
(none) |
H&E |
B85, Penis, 1x |
|
53 |
Superficial Dorsal Vein |
(none) |
H&E |
B85, Penis, 1x |
|
54 |
Tunica Albuginea (of Penis) |
(none) |
H&E |
B85, Penis, 1x |
|
55 |
Deep Fascia |
(none) |
H&E |
B85, Penis, 1x |
|
56 |
Skin |
(none) |
H&E |
B85, Penis, 1x |
|
57 |
Trabeculae (Connective Tissue and Smooth Muscle) |
T |
H&E |
B85, Penis, 20x |
|
58 |
Lacunae (Vascular Space) |
L |
H&E |
B85, Penis, 20x |
|
59 |
Endothelium |
En |
H&E |
B85, Penis, 20x |
|
60 |
Corpus Spongiosum |
CSP |
H&E |
B85, Penis, 2.5x |
|
61 |
Urethra |
U |
H&E |
B85, Penis, 2.5x |
|
Top of page
- My bad. Nevertheless, I am a little confused about the testis table compared to the review table. Why are the EDs omitted from the testis table? Are they not part of the testis? I realized that clicking on the "structure" column was handy. I imagine that row sorting reflects order of discussion. I expected, incorrectly, alphabetization of IDs and then did not notice they were not sorted. Thus, I immediately went to the "E's" and did not find ED. Plus, ED is not in the testis table proper. Perhaps a discreet note could remind the user that the columns are sortable. -- LorenEvey - 09 Jul 2007
- See, now you are just toying with me. Look here : EDs -- AshleyLPistorio - 09 Jul 2007
- Hey, while you are at it, let's label an efferent ductule. -- LorenEvey - 09 Jul 2007
- Oh, they are not equal as far as I know. The helicine aa are like curly little offshoots of the deep aa that feed the spaces of the trabeculae. I'll probably deal with this during my editing process. You said the text equated them? Which text - here or HH? You know, Dr. H is not infallible. -- AshleyLPistorio - 07 Jul 2007
- The text equates them with trabeculae. I am just getting back on board with your efforts. This is looking great. What caught my attention was the relationships between Bucks f., Superf. Dorsal vv., Deep Dorsal v., Dorsal n., and Dorsal a. I can foresee that this atlas might, on occasion, get referenced from the gross course. Perhaps from the message boards. I was merely thinking ahead. Particular affinity? -- LorenEvey - 07 Jul 2007
- Don't know that I see one in the 1x slides. Did you find one? You have a particular affinity for the helicine aa.? -- AshleyLPistorio - 07 Jul 2007
- Hey, can we (you ) include a label for the helicine aa? -- LorenEvey - 07 Jul 2007
Top of page
--
AshleyLPistorio - 27 May 2007