Identification of the Organs of Male Genital System under Microscope
Hello and welcome again. Hope you are doing well. Today, I will discuss the identification of the organs of a male genital system under a microscope. It would be best to have a basic idea about STRUCTURE OF CELL, LINING EPITHELIUM and CONNECTIVE TISSUE, and GENERAL STRUCTURAL PATTERN OF A TUBULAR ORGAN. If you don’t have basic knowledge about those topics, you may go through those links.
You know, there are many histological features of an organ, but here we will discuss the important histological features needed to identify the organ under a microscope. Let’s start –
Organs of the male genital system:
We need to identify the following organs from the male genital system under the microscope –
Testis
Ductus epididymis
Ductus deference
Accessory male genital glands (seminal vesicles, prostate gland, and bulbourethral gland)
Urethra and penis
Now I am going to discuss the main histological feature of the organs as mentioned earlier.
Testis:
First, we should know what important histological features need to identify under a microscope. We will identify the following structures or features –
Tunica albuginea
Septula testis and mediastinum testis
Seminiferous tubule
Spermatogenic cells (Spermatogonia, spermatocytes, spermatids, spermatozoa)
Supporting or sustentacular or Sertoli cell
Leydic or interstitial cell
Okay, let’s identify those features or structures
Tunica albuginea: It is a solid, dense irregular connective tissue capsule rich in collagen fibers, few elastic fibers, and myofibrils.
Septula testis and mediastinum testis: When tunica albuginea continues with connective tissue trabeculae and divides the parenchyma of the testis into different lobules, it is called septula testis. It again converges with mediastinum testis, located at the central portion of testis in ruminant and dog. But, the stallion, cat, and another rodent are located at the marginal portion of the testis.
Seminiferous tubules are tortuous and lined by STRATIFIED GERMINAL EPITHELIUM (Spermatogenic cells, Sertoli cells, Leydig cells).
Spermatogenic cells are located between and above the SERTOLI CELLS (so we need to identify them first). Spermatogenic cells are –
Spermatogonia
Spermatocytes (primary and secondary spermatocytes)
Spermatid and
Spermatozoa
Spermatogonia: They are immature spermatogenic cells (having oval dark or light stained nucleus) that lie on the basement membrane of the seminiferous tubule.
Spermatocytes: There are two types of spermatocytes –
Primary and secondary spermatocytes
Primary spermatocytes are the largest germ cells located at the middle portion of the seminiferous tubule with a large oval nucleus, whereas secondary spermatocytes are smaller germ cells than primary spermatocytes and have a smaller nucleus with less dense chromatin.
Spermatid: They are smaller than the spermatocytes, and they remain in a small group and towards the lumen of the seminiferous tubule.
Spermatozoa: They are motile elongated male gametes. Their head found a close association with Sertoli cell, and the tail remained towards the seminiferous tubule’s lumen.
Sertoli cells: They are elongated cells with irregular outlines. The base of the cell rest on the basement membrane, and the cytoplasm remain extends upward to the tubular lumen. They have oval shape nucleus, and they are located need to the basement membrane of the seminiferous tubule.
The main functions of Sertoli cells are – nourishing, protective and supportive functions; they mediate the action of FSH and testosterone; helps to produce androgen binding protein.
Interstitial cell or supporting cell or Leydig cell: They remain in the interstitial connective tissue of among seminiferous tubule. They remain in a cluster form and have a large polyhedral nucleus.
The main functions are – they secrete male sex hormone called testosterone (helps in spermatogenesis)
Ductus Epididymis:
It would be best if you had the basic idea of the organizational pattern of the tubular organ. The ductus epididymis has three parts – head, body, and tail. We will identify the following structure of ductus epididymis under the microscope –
Lining epithelium and stereocilia
Smooth muscle layers underlining epithelium
Spermatozoa in the lumen of epididymis
Okay, let’s start to identify ductus epididymis under a microscope.
Ductus epididymis is extremely tortuous and winding which is lined by pseudostratified columnar epithelium with stereocilia (stereocilia become gradually shorter toward the tail region).
Presence of inner circular and outer longitudinal smooth muscle layers (the thickness of the muscle layers is increased towards the seminiferous tubule’s tail end).
You will find spermatozoa in the lumen of ductus epididymis (as it transport sperm)
Ductus Deferens:
Here, it would help if you also had a basic idea of the structure of the tubular organ. We need to identify the following structure of ductus deferens under the microscope –
Lining epithelium with stereocilia
Lamina propria
Muscular layers (three or two layers)
Adventitia
Spermatozoa
Okay, let’s start to identify those structures.
The mucosa of ductus deferens has a longitudinal fold that gives the star-shaped lumen and is lined by pseudostratified columnar epithelium to the simple columnar epithelium (towards the end portion) microvilli.
In the muscular layer, you will find the inner longitudinal, middle circular, and outer longitudinal muscle layer in stallion, bull, and boar, whereas, in small ruminant, you will find the inner circular and outer longitudinal layer of smooth muscle.
Accessory glands:
We will identify the histological feature of the seminal vesicle, prostate gland, and bulbourethral gland. Let’s start to identify –
Seminal vesicle:
It is an elongated blind tubule. We need to identify the following structure –
Anastomosing mucosal fold
Lining epithelium
Smooth muscles layers
Adventitia
Okay, let’s start to identify those structures
The mucosa of seminal vesicle formed branching, and again, those branching anastomosed to form cavities lined by pseudostratified columnar epithelium to simple columnar epithelium.
In lamina propria, you will find the more elastic fibers
In muscular layer, you will find inner circular and outer longitudinal layers of smooth muscles
Prostate gland:
It is a tubuloalveolar gland. We need to identify the following structures –
Prostatic alveoli with lining epithelium
Prostatic concretions
Fibro-muscular stroma
Okay, let’s start to identify those structures of the prostate gland under a microscope.
Hope you are well known for the parenchyma and stroma of a gland. Here in the prostate gland, you will find parenchyma and fibromuscular stroma.
Large irregular prosthetic alveoli form the parenchyma with a wide lumen, and these prostatic alveoli are lined by simple cuboidal to columnar epithelium. This simple epithelium changes to the stratified columnar or transitional epithelium in the terminal portion of the ducts.
The lumen of prostatic alveoli contains prostatic concretion of corpora amylacea.
The fibromuscular stroma is made with smooth muscle fiber and connective tissue fibers.
Bulbourethral gland:
It is compound tubular (boars, cats) and tubuloalveolar gland (stallion, bull, rams). We need to identify the following structures –
Capsule
Lining epithelium
Okay, let’s start to identify –
The secretory portion of the gland is lined by simple columnar epithelium
Presence of fibroelastic capsule containing a variable amount of striated muscle
Urethra and penis:
We need to identify the following structures under the microscope –
Urethra – mucosal fold, lining epithelium, tunica muscularis
Muscles of the penis – corpora cavernosa and corpora spongiosum muscles
Okay, let’s start to identify those structures –
Presence of corpora cavernosa muscle and corpora spongiosum muscles. In corpora spongiosum muscle, you will find the urethra.
Mucosa of urethra having longitudinal fold and lined by transitional epithelium (varies with function – stratified columnar, cuboidal epithelium)
Presence of propria submucosa, which consists of loose connective tissue, elastic fibers, and smooth muscles cells, and diffuse lymphatic nodules
Tunica muscularis consist of smooth muscle or striated muscles layers
Conclusion
I Hope you have got an idea on identifying organs of the male genital system under a microscope. You may also learn the basic histology of the organs from DIGESTIVE SYSTEM, RESPIRATORY SYSTEM, URINARY SYSTEM, MALE GENITAL SYSTEM, and FEMALE GENITAL SYSTEM. If you want to get more information on those topics, you should follow the class lecture or go through the BOOK for more.
If possible, I will update or enrich the information on this topic in the future.
If there is any mistake in the above information or any suggestions for me, please, let me know in the comment box. Thank you so much.