WEEK 4: HISTOLOGY OF THE MALE REPRODUCTIVE SYSTEM Flashcards
State the cell types found in the seminiferous tubules of the testes?
*spermatogonia
*primary spermatocytes
* Secondary spermatocytes
*spermatids
*sertoli cells
Describe the epithelium of the seminiferous tubules.
Consist of germinal epithelium and basement membrane
*Epithelium contains various stages of spermatogenic cells and supporting cells = Sertoli Cells
Describe the function of the interstitial tissue.
*Separates seminiferous tubules
Where are the Leydig cells in the testes?
What are functions of Leydig cells?
How can they be recognized?
What are eosinophilic cytoplasmic inclusions that they contain called?
In the interstitial tissue surrounding the seminiferous tubules and occur in clusters.
Secrete testosterone.
*Recognized by round nuclei and extensive acidophilic cytoplasm.
*May contain small eosinophilic cytoplasmic inclusions called Reinke’s crystalloids.
Where are sperms produced in the testes?
seminiferous tubules
State the 3 coverings for the testis
*Tunica viginalis
*Tunica albuginea
Tunica vasculosa
What is the rete testis?
the network of channels
What are the functions of the rete testis?
transports gametes from the testes to the efferent ducts
The rete testis is lined with cuboidal epithelium which has occasional microvilli.
State the function of this microvilli
function as chemoreceptors allowing the lining cells to monitor and modify the luminal contents)
What is the only portion of the male tract that display true, motile cilia?
The efferent duct
Describe the epithelium of the efferent duct
simple columnar, and consists of two cell types, taller cells have with cilia and shorter cells without cilia
Describe the epithelium of the epididymis
*The epithelium of the duct is pseudostratified columnar.
*The tall epithelial cells havelong microvilli
on their apical surface, sometimes called “stereocilia”, although they arenotcilia at all)
Describe the epithelium of ductus deferens/ Sperm duct.
It is characterized by
*a narrow lumen.
*Mucosa with longitudinal folds, lined mostly by pseudostratified columnar epithelium with stereocilia.
*Lamina propria: is rich in elastic fiber.
Muscular wall: is thick and consist of 3 layers.
-inner longitudinal and
-outer layers of mostly longitudinal smooth muscle fibers a
-middle layer of mostly circular fibers.
Has moderately-abundant smooth muscle in the wall.
The epithelium of this gland lies on the surface of interconnecting mucosal folds that extend into the lumen from the muscular wall.
The sparse connective tissue within the folds constitutes the lamina propria of this mucosa.
The epithelium, which may be either simple columnar or pseudostratified columnar, produces a secretion (including fructose, ascorbic acid and other components) which is expelled from the gland by contraction of the muscular wall during ejaculation, constituting about 50-80% of the semen.
What structure is this?
Seminal vesicle.
Describe the prostate.
*All appear rather irregularly tubular with a convoluted epithelium lined by columnar, secretory cells.
*The secretory tissue is embedded in an extensive fibromuscular stroma that contains both collagen and smooth muscle, thoroughly interwoven.
*Glandular lumens may normally contain small acidophilic concretions called corpora amylacea.
*The prostate consists of irregular glands embedded in an extensive fibromuscular stroma.
Describe the urethra.
The urethra has a muscular wall and a mucosal lining with a transitional epithelium (urothelium), a stratified epithelium in which both cell shape and number of layers can change markedly during the normal process of distension.
Describe the penis.
*The erectile tissue is organized into paired dorsal corpora cavernosa and one ventral corpus spongiosum.
*The corpora cavernosa is surrounded by tough fibrous connective tissue, the tunica albuginea.
*Between this sheath and the overlying skin is a layer of very loose elastic connective tissue (Buck’s fascia) that permits the skin of the penis to move freely along the shaft.
*The skin includes a smooth muscle layer (the dartos).
*The penile urethra passes through the corpus spongiosum, where it is associated with small mucous glands of Littre.
What is the vaginal cavity?
The space between the parietal and visceral layres of the tunica vaginalis
There are two types of spermatogonia.
Type A and B.
What are their functions?
*Type A:serve as sterm cells of the germinal epithelium
*Type B: undergo maturation to form the primary spermatocytes
Which are the largest germ cells in the seminiferous tubule?
Primary spermatoctes
What is the function of sertoli cells?
*Sertoli cells are support cells
*Form a simple columnar epithelium.
*Sertoli cells provide blood-testis barrier
*Secrete fructose, androgen binding protein, anti-Mullerian hormone, inhibin, and activin
*Moreover, occluding junctions between adjacent Sertoli cells establish a blood testis barrier that protect the developing germs cell form autoimmune phenomena
*Specific Sertoli cell functions include:
-Nutritional support
-Phagocytosis of residual bodies (shed cytoplasm) from spermatids
-Secretion.
What are the functions of myloid cells?
*Each seminiferous tubule is surrounded by a thin layer of contractile myoid cells
*Produce waves of contraction to move immature (and not yet motile) spermatozoa out of the testis.
Outline the hierarchy for sperm cell formation.
Spermatogonia
Primary spermatocytes
Secondary spermatocytes
Spermatids
Spermatozoa
Describe the pathway of spermatozoa.
*Spermatozoa leave the seminiferous tubules via the tubuli recti (straight tubules)
*From the tubuli recti to the rete testis (randomly arranged)
*Efferent ductules which lead to the extra testicular ducts
*Ductus epididymis
*Ductus / Vas deferens
*Ejaculatory ducts of the prostate
*Urethra
