BE ABLE TO IDENTIFY:
Ovary-- be able to identify this organ and the following components:
cells-- granulosa, granulosa and theca lutein, primary oocyte
corpus albicans and luteum
germinal epithelium (mesothelium of peritoneal cavity)
ovarian cortex and medulla
primordial, primary, and antral (secondary) follicles
Oviduct-- be able to identify this structure and the following components:
peg (secretory) and ciliated cells
Uterus-- be able to identify this organ and the following components:
endometrium (stratum basalis and functionalis)
phases of endometrium
Mammary gland-- be able to identify this organ and the following components:
active and inactive gland
Slides #140 and #168 (168 is better slide) (Human ovary) Locate the tunica albuginea. You may have mesothelium (germinal epithelium) covering it in your specimen. Also locate the cortex and medulla. Within the cortex, identify the primary oocytes in follicles. Note that the medulla is composed primarily of connective tissue and blood vessels. Identify primordial, primary, and secondary follicles.
Primary Ovarian Follicle - As soon as the primordial follicle grows a bit and the epithelium becomes cuboidal or stratified cuboidal it becomes a Primary Follicle. The epithelium is called follicular epithelium and later in the follicle's development it will be called the granulosum layer. Texts vary in where they decide to change the name so either name will be accepted as correct at all stages.
Identify the theca interna. In maturing follicles locate the antrum, cumulus oophorus, oocyte, granulosa cell layer, and zona pellucida. (That part of the cumulus oophorus that leaves the follicle with the oocyte during ovulation is called the corona radiata. (Many of your atlases have applied this label when they should have used "cumulus oophorus.")
Remember that any of these stages can begin to degenerate and become an atretic follicle. The appearance of an atretic follicle will depend on how mature the follicle was when it began to undergo atresia. How far the follicle is into the process of atresia also plays a role: young and old atretic follicles look VERY different. [See your text books and atlases, especially Ross, Romrell, and Kaye (3rd. ed.), p. 716.] What is a pyknotic nucleus? What is a zona pelucida remnant? What is a glassy membrane? This is a young atretic follicle being formed by the breakdown (death) of a large secondary follicle. Compare with healthy secondary follicle above.
These are late (old) atretic follicles that appear to be remnants of primary follicles. They are smaller than the early atretic follicle above which is derived from a larger secondary follicle. Compare the sizes of the primordial follicles in each micrograph above for reference and notice the outlines of two of the late atretic follicles. What is the pink stained object in the center of each of these late atretic follicles?
Slide #97 (Human ovary, corpus luteum of pregnancy, Low Mag.) The corpus luteum is very large. Only a portion of it will be shown on some sections. Note the connective tissue-filled follicular cavity surrounded by the corpus luteum. In the latter, identify granulosa lutein cells and theca lutein cells. Where do they originate?
Corpus Luteum - medium magnification, The corpus hemorrhagicus shows in the upper right of this image. At this magnification the granulosa lutein cells appear to be light colored with individual nuclei visible. The theca lutein cells are smaller and darker. It is difficult to make out their individual nuclei. The structure labeled BV is a blood vessel.
The blood vessels and the theca lutein cells are located in an infolded portion of the former Theca Interna region of the follicle.
High magnification of the Corpus Luteum - At this magnification it is easy to see the difference in size between the Granulosa Lutein Cells and the Theca Lutein Cells.What is the function of each of these cell types?
Slide #96 (Human ovary, corpus albicans) Besides the corpus albicans, what other structures can you identify in this slide? What is a corpus albicans? Can you distinguish a corpus albicans from an atretic follicle? You might want to think about that. A big old atretic follicle might look a lot like a corpus albicans; what are a couple of indicators that you are looking at the former and not the latter?
II. Uterine Tube (oviduct, Fallopian tube)
Slide #89 (Human ampulla of Fallopian tube, uterine tube, or oviduct) Note the great complexity of the luminal folds. Locate ciliated cells and "peg" (secretory) cells. "Peg" cells project into the lumen of the tube. This is the portion of the tube where fertilization usually takes place.
Different slide of Ampulla of Oviduct.
Sightly different fixation and staining results in what may appear at first glance to be very different than the tissue shown above. However, careful observation of both specimens shows that they contain the same structures.
Slide #88 (Human oviduct. fallopian tube) The oviduct is made of three layers: mucosa, muscularis, and serosa. Identify ciliated and peg cells in the simple columnar epithelium. The muscularis is quite thick here.
To get you started, if glands are short and straight, the endometrium is in the proliferative (follicular) phase. If glands are long and coiled or even sawtoothed and maybe even with secretory product in lumen, it's secretory (luteal) phase. If glands are disrupted, the epithelium gone, and the stroma is filled with RBC's, it is in the menstrual phase.
Slide #72 (Human uterus, follicular or proliferative phase) Note increase in size of gland cells. The increase in stromal edema and vascularity that will be conspicuous later is not clear yet apparent here. The glands may be straight or slightly convoluted.
Slide #70 (Human endometrium, luteal or secretory phase) This tissue clearly shows the increased stromal edema and gland cell hypertrophy. Note the irregular shape of the once straight tubular glands. Note secretion in some glandular lumina.
Slide #71 (Human uterus, menstrual phase) Note the dramatic increase in vascularity and edema. Evidence of degenerative processes demonstrating autolysis and hemorrhage is apparent.
To get you started, if glands are short and straight, the endometrium proliferative (follicular). If glands are long and coiled or even sawtoothed and maybe even with secretory product in lumen, it's secretory (luteal). If glands are disrupted and the stroma is filled with RBC's, it's menstrual.
Slides #74 and #137 (Human uterus, cervix these slides are of variable quality borrow) Note the epithelium in the cervix is generally higher columnar than elsewhere in the endometrium. Towards the vaginal end, the luminal epithelium changes abruptly to stratified squamous. Branched mucous glands may be present. Cells are scraped from the vaginal portion of the cervix for what test?
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HISTOLOGY LAB XVII - MALE REPRODUCTIVE SYSTEM
BE ABLE TO IDENTIFY:
Testis-- be able to identify this organ and the following components:
adventitia (aka lamina propria or tunica propria) of seminiferous tubules
cells-- Leydig, Sertoli, spermatid, spermatocyte, spermatogonium, spermatozoan
tunica vaginalis (peritoneum)
Miscellaneous male tubules-- be able to identify
epididymis-head and tail
Penis-- be able to identify this organ and the following components:
corpus cavernosum and spongiosum
gland of Littre
Prostate-- be able to identify
prostate (young and old)
I. Testis and Passages
Slides #76 & 178 (Testis). Note the tunica albuginea. On the outside of the tunica albuginea, you may be able to see the visceral layer of the tunica vaginalis testis. What does this represent? What type of tissue? Notice the large blood vessel in this section and inside of that the Tunica Vasculosa. Connective tissue septae from the Tunica Vasculosa separate the seminiferous tubules from one another.
Looking through the testis, you should note many seminiferous tubules in cross and oblique section, irregular connective tissue septae, and interstitial (Leydig) cells. Focus your attention on the seminiferous tubules. Identify: adventitia (lamina propria) of tubules, various stages of spermatogenesis and Sertoli cells. The latter are readily identified by the presence of an elongate "notched" nucleus with a large dark nucleolus. Locate the examples of the following stages of sperm development: spermatogonia, primary spermatocytes, spermatids, and mature spermatozoa.
Secondary spermatocytes are rarely found and cannot be differentiated from primary spermatocytes very easily. They should be visualized within your mind through the use of a now well-trained vivid imagination. Though a cell may look very much like a mature spermatozoan, if it is still part of the tubular epithelium, it is still a spermatid. It becomes a spermatozoan only when it is released.
High magnification image of the interstitial tissue between seminiferous tubules. In this interstitial tissue are three Interstitial (Leydig) cells. They have a round nucleus with a prominent nucleolus. If you look carefully you can see some secretory granules in the cytoplasm of these cells. These granules contain testosterone and will be secreted into the surrounding connective tissue where they will migrate either to the adjacent seminiferous tubules or to the capillaries nearby. This method of secretion where no ducts are involved is endocrine secretion.
Scanning Electron Micrograph of a single seminiferous tubule. The obvious structures are labeled. Other cell types are not as easy to recognize in this type of preparation. However, it does give one a feeling of the three dimentional structure of the tubule.
Slide #76 (Tubuli Recti) Many of you have good slides showing this tubular segment that connects the seminiferous tubules to the rete testes. If you don't, borrow from someone who does.
Slide #77 (Human rete testis) Understand the anatomical/histological relationships of the rete testis and mediastinum testis even if not clearly evident on your slide. What type of epithelium lines the channels of the rete?
Slide #78 (Efferent Ducts) A few of you will have some great ones but most of you will have none; see demonstration and your atlases. These tubes are easily identified because they are the only tubules with an epithelium some of which is high (and ciliated) and some of which is low (and not ciliated).
Slide #78 (Human epididymis) Identify: pseudostratified columnar epithelium consisting primarily of tall principal cells (getting shorter distally) with stereocilia (getting shorter distally) and basal cells. Surrounding the epithelium is a coat of smooth muscle (that thickens distally). At the junction with the ductus deferens (not shown), this coat is trilaminar. In other words, as one moves from head to tail, the epithelium gets shorter, the stereocilia get shorter, and the muscle gets thicker.
Slides #79 & #158 (Ductus deferens, human) Note the longitudinal folds in the mucosa, which are lined by pseudostratified columnar epithelium. Find the smooth muscle layers and lamina propria. What is the function of the extremely thick muscular coat?
Slide #81 (Human ejaculatory duct) The epithelium is simple or pseudostratified columnar. Mucosal folds reach far into the lumen. This structure may not appear as a single lumen where the two join within the prostate gland. Often an ejaculatory duct can be identified because it looks like some kind of male tube surrounded by dense irregular connective tissue (in this case, prostate stroma) rather than smooth muscle.
Male Repro - Ejaculatory Duct (Demonstration)
II. Accessory Glands and Penis
Slide #80 (Human seminal vesicle) Note the marked luminal folding. In section, this gives the appearance of isolated tubules, but in reality there is one continuous complex lumen. The muscular coat is substantial but not nearly as much as in the ductus deferens. The epithelium is simple or pseudostratified columnar.
Male Repro - Seminal Vesicle (Demonstration)
Slide #94 (Young human prostate) This compound tubuloacinar gland is embedded in a stroma of connective tissue and smooth muscle. The secretory portions are lined with cuboidal-columnar epithelium.
Slide #82 (Old human prostate) Note the increase in prostatic concretions. Note prostatic concretions in a few of the lumina. There are fewer glands present and more connective tissue.
Slide #103 (Human penis) Locate: corpora cavernosa, corpus spongiosum, urethra, tunica albuginea, dermis, epidermis. The urethral epithelium is stratified columnar in many of the slides. Do you see any glands of Littre? These are intra- and subepithelial mucous glands that occur throughout the male and female urethra.
Male Repro - Urethra (Demonstration)
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