Objectives:

147C Testis, human
This slide shows only seminiferous tubules and some tunica albuginea. The stain is iron-hematoxylin which stains the erythrocytes very dark as well as the sperm heads. A notable feature of this slide is the visibility of Ad spermatogonia. These are identifiable by the very dark nuclei located at the base of the tubules. They are relatively infrequent. Ap and B spermatogonia can be identified by the pale staining nucleus in the former case and the speckled staining nuclei in the latter case. Sertoli cells, normally difficult to identify under the best conditions are virtually invisible. Some basal nuclei can be found with prominent nucleolus and these are probably the Sertoli cells. Primary spermatocytes are the large nuclei with the stringy looking chromatin. They are positioned above the spermatogonia. Spermatids in all stages can be found but because the cytoplasm is virtually unstained, only the nuclei give a clue to the stage of development. Leydig cells can be found. They have a large pale staining nucleus with prominent nucleolus. They are positioned near the capillaries, which have heavily stained RBCs within their lumen.

 148A Rete Testis, human, H&E
148B Rete Testis, human, Masson 

This slide contains seminiferous tubules, tunica albuginea and rete testis. The epithelial preservation of the seminiferous tubules is not good so do not bother to try identifying cell types. There are no sperm in the tubules. In the Masson stained slide, What stands out particularly well are the Leydig cells. They can be visualized as dark clusters of cells in the spaces between tubules. If you follow the t. albuginea to a septa, you will see chambers lined with a low cuboidal epithelium which is the rete testis. At higher power, you can see flattened nuclei in the tunica propria surrounding the seminiferous tubules. These are the hyoid cells that help propel the sperm down the tubules to the rete testis.

149B Testis & epididymis

This is probably the best slide for looking at the different stages of sperm development. However, it is not human or primate. Some of these slides have mediastinum in the center of the testis and within it are the rete testis, easily identifiable by the cuboidal epithelium. Leydig cells are large cells with foamy cytoplasm and prominent nucleoli found within the interstitial space. Within the seminiferous tubules, primary spermatocytes (1° Sc) abound as do spermatids (Sp) in different stages of development. Spermatogonia (Sg) seem to be mostly B type. The cells with large prominent nucleoli are most likely Sertoli cells (Sn). These nuclei are found both basal and midway up the epithelium. Compare the spermatids with Fig. 21.10 in RR&K and see if you can identify any of these stages. In the epididymis, the stringy structures at the apex of the epithelium are the stereocilia. Basal cells are sparse with nuclei very close to the basal lamina. Sperm are found in the lumen.

A. Tall pseudostratified columnar epithelium with stereocilia (long microvilli)
B. Spermatozoa are often found in the lumen
C. Surrounded by smooth muscle which goes from single to triple layer as you move towards the distal end of the epididymis
D. Epithelium decreases in height as you move distally

150A Epididymis, human, sec.

These slides have a small amount of seminiferous tubules attached, but otherwise all the tubules are epididymis. The slide contains regions which have principle cells of different height, characteristic of head and tail. Which corresponds to which. The lumen of man of the tubules contain sperm. The stereocilia are not visible as a distinct feature, but rather tend to bunch together, which makes them visible in the light microscope. Note how the epithelium is of uniform height in each tubule cut in cross section. This is highly characteristic. Note also how it differs from the seminiferous tubules which have a very different structure.

A. Pseudostratified columnar epithelium with stereocilia
B. Epithelial lining and lamina propria are thrown into folds to allow for expansion during ejaculation
C. Smooth muscle layers

151A S. Cord, Masson, human
This is a nice slide of vas deferens that also includes some elements of the pampiniform plexus. The three layers of smooth muscle surrounding the vas are very clear. The epithelium is pseudostratified columna with stereocilia and the lumen is full of sperm, which is a characteristic of most of the spermatic cord including epididymis. The arteries and veins of the pampiniform plexus are well preserved and worth more than a passing glance. There is a piece of skeletal muscle near the pampiniform plexus, the cremaster muscle.

151B Spermatic cord, human
There is plenty in this slide to be confusing. Toward the right of the slide is the vas deferens itself. It is lined with a pseudostratifed columnar epithelium with stereocilia, which appear as thin hairlike apical projections. In the center are clumps of sperm. The most prominent smooth muscle layer is the middle circular. The outer longitudinal is next and the inner longitudinal is the thinnest. A thin lamina propria lies between the epithelium and inner muscle layer. There are numerous blood vessels in the tissue, both arteries and veins. These are the pampiniform plexus. RR&K describe these veins as having an inner layer of longitudinal smooth muscle, but I don’t see this. They have a well developed outer layer of longitudinal smooth muscle but that would make them simply medium or large veins.

152A Spermatic cord, human, H&E
152B Spermatic cord, human, Masson

These companion slides reveal several structures in the region of the spermatic cord. This organ runs parallel with the pampiniform plexus that here is composed of veins with longitudinal smooth muscle (B), (C), cremaster muscle (D) as well as the testicular artery. The testicular artery (C) is the large blood vessel that lacks longitudinal smooth muscle. The spermatic cord (A) is identifiable by the three smooth muscle layers and the pseudostratified columnar epithelium. This slide resembles in many ways 151a.

153A Vas deferens, human, H&E
153B Vas deferens, human, Masson

This is a region of the vas closer to the ampulla. As the vas progresses from the epididymis to the prostate, the lumen becomes more folded. In the ampulla of the vas, the epithelium is highly folded. The three layers of smooth muscle are not as clearly defined as they were in slide 152, but if you look at the Masson stained slide, you may be able to better discern these layers. The epithelium is not well preserved, but you can see the pseudostratification. The tall microvilli are not apparent.

154B Seminal vesicle

This slide is actually mostly prostate. The seminal vesicle portion is to only one side and not very complete. However, the presence of pieces of both tissue may help you to learn to distinguish between the two organs. In the bulk of the tissue, look for glands with concretions which are diagnostic of prostate. Also note in comparison the much more extensive folding of the seminal vesicle epithelium. Usually, the seminal vesicle will display a much larger diameter gland with many blind diverticula. Smooth muscle is prominent around all of the glands.

154C Seminal vesicle 
This is probably the best slide of seminal vesicle. It shows the highly folded mucosa. Two separate layers of smooth muscle can be seen surrounding the glands in many places. The section is quite thick and you will be able to focus through at least 2 cell layers. Keep in mind the extensive folding when you compare this organ with the prostate.

A. Tubuloalveolar glands
B. Urethra passes through (urinary (transitional) epithelium)
C. Ejaculatory ducts join urethra just prior to its exiting of prostate gland
D. Epithelium of glands

155B Prostate, young human

At low magnification this tissue resembles quite well the example shown on Plate 110. At higher magnification, the staining is insufficient to highlight smooth muscle over connective tissue. Most of the strands of tissue running through the stroma are smooth muscle. The organization of the epithelium is pseudostratified columnar. Even though this slide is said to be from a younger male, some of the slides show concretions within the glands. The capsule is present in most of the slides but the urethra and ejaculatory duct are not. Most of the glands are most likely main prostatic and submucosal glands.

155A Prostate, H&E, Human
The glands in this tissue are relatively sparse and surrounded by considerable fibromuscular CT. The height of the epithelium is variable and ranges from pseudostratified columnar to simple cuboidal.

 
155E Prostate sec
This is not a human prostate but it displays most of the salient features. There are two groups of slides with this designation. In one group (with the orange Ward’s label), the prostatic urethra is present. This particular slide has some striated muscle attached to the gland, which may be a voluntary sphincter for the urinary bladder. (Striations are extremely difficult to see in this muscle, but can be seen in some places by stopping down the condenser. The overall arrangement with peripheral nuclei is characteristic, however) The prostatic urethra is lined with a transitional epithelium. The glandular epithelium is of varying height; in some cases it looks cuboidal, in others pseudostratifed columnar. The glands are organized into lobules and surrounding each lobule, is a layer of cellular CT that is mainly smooth muscle. The capsule is present but under it is considerable smooth muscle, identifiable by its darker staining. Secretory product fills the glands.

155D Prostate, H&E
This may not be human tissue. Note how small the glands are compared with those shown in the previous 3 slides. The prostatic urethra is present as well as the voluntary sphincter around the urethra. The stroma contains large numbers of smooth muscle cells, identifiable by the large, oval nuclei.

155F Prostate, human
This slide is a well preserved piece of prostate. Note the high degree of folding of the mucosa. There is very little connective tissue surrounding the mucosa. Most of the surrounding tissue is smooth muscle. If you look carefully, you should be able to verify that the inner layer of smooth muscle, right under the epithelium is circular in orientation. The outer layer is incomplete and is most prominent where the separation between glands is largest. In this preparation, connective tissue is much more lightly stained than smooth muscle. The epithelium is pseudostratified columnar but the highly folded nature of the mucosa makes it difficult to find a thin longitudinal view through the columnar cells. Some of the glands have concretions in them (rounded, reddish objects without noticeable nuclei). This is characteristic of prostate from older males and is diagnostic if present.

This penis has been cut in half longitudinally. You are thus seeing only one half of the organ. Note the presence of glands in the submucosa of the urethra and in the epithelium in some slides. Note the thick t. albuginea surrounding the corpora cavernosa and the deep dorsal vessels (both an artery and a vein).

157B Penis, Masson, human
This is a section through the fossa navicularis of the glans and seems to be longitudinal with respect to the urethra. This allow you to see the transition from stratified squamous to pseudostratified columnar. The pseudostratified columnar epithelium seems to be rather tall, a bit reminiscent of the respiratory epithelium, but this may simply be that nowhere is the epithelium sectioned longitudinally with the result that the minimal thickness is not displayed. You should be able to convince your self that this epithelium is certainly not stratified squamous because of the rounded nuclei on the surface and the rather greater apical cytoplasm than in seen in the stratified squamous epithelium. The surface epithelium is stratified squamous, keratinized and is rather thin. Underlying the surface of the glans are extensive vascular spaces, which are part of the corpora spongiosum extension into the glans.

 
157C Penis, McFar., Human
There are only 3 slides of this tissue, and one is clearly superior to the other which shows only the c. spongiosum. This is a cross section through the penis and shows both the corpora cavernosum and the corpora spongiosum. If you look at the slide by eye, you will have no problem distinguishing the different regions. The epidermis has been removed. Surrounding the c. cavernosum is a very thick and dense connective tissue, which will appear deep blue in color. This is the tunica albuginea. The vascular spaces are collapsed. Within the c. spongiosum is the urethra. It is lined with a pseudostratified columnar epithelium. Because of the folding of the urethra, you will have some trouble convincing your self that this is pseudostratified and not transitional. Look for relatively thin places. Surrounding the urethra are some mucous glands, glands of Littré. Some of these glands are actually in the epithelium of the urethra. Just outside of the t. albuginea are some peripheral nerves and large muscular arteries.

156 Penis, monkey, c.s

There are several groups of slides with this number. They are all transverse sections through the entire organ. Some of these seem to have only a single c. cavernosum. Notice the thick t. albuginea surrounding the c. cavernosum. Within the c. cavernosum are a pair of arteries running down the center accompanied by a nerve bundle. Surrounding the t. albuginea are numerous arteries and nerve bundles. The epithelium of the urethra is pseudostratified. You will again have to look for regions where it is sectioned optimally to confirm this. Look for elongated nuclei with their axis perpendicular to the epithelium plane. The surface epithelium is stratified squamous, keratinized and lacks hair follicles, obvious glands or encapsulated nerve endings. Another group of slides comes from the body of the penis, and a third from the prepuce region. Note that the epidermis surrounding the organ is completely devoid of hair. Both corpora cavernosi are completely collapsed. The urethra is pseudostratified columnar and can be compared with the epidermis to confirm that it is not stratified squamous.

 

testes  tunica vaginalis  testicular artery  pampiniform plexus  tunica albuginea  tunica vasculosa  mediastinum  rete testis  Leydig cells  crystals of Reinke tubuli recti  seminiferous tubules  seminiferous epithelium  spermatogenic cells  spermatogonia  type Ap  type Ad  type B Sertoli cells  karyosomes  junctional complex  blood-testis barrier  androgen binding protein spermatids  tunica propria  myoid cells/peritubular contractile cells  cycle of seminiferous tubules hormones  testosterone  follicle stimulating hormone  luteinizing hormone/interstitial cell-stimulating hormone  prolactin  inhibin

spermatogenesis  spermatogonial phase  spermatocyte phase (meiosis)  primary spermatocytes  secondary spermatocytes spermatid phase (spermiogenesis)  Golgi phase  proacrosomal granules  acrosomal vesicles  axonemal complex cap phase  acrosomal cap acrosome phase  manchette  connecting piece/neck region  middle piece  fibrous sheath  principal piece  end piece maturation phase  residual body mature sperm  head  acrosome reaction  tail  efferent ductules  coni vasculosi epididymis  ductus epididymis  principal cells  basal cells  halo cells  stereocilia ductus deferens  ampulla ejaculatory duct  seminal vesicles  mucosal arches prostate  prostatic concretions/corpora amylacea bulbourethral glands/Cowper’s glands  semen penis  corpora cavernosa  corpus spongiosum  tunica albuginea  helicine arteries  glans  prepuce