Male Reproductive Flashcards
Testis and epididymis function
Seminal vesicle, prostate and bulbourethral gland function
Ductus deferens, ejaculatory duct and penis function
The testes histology
Seminiferous tubules histology
The seminiferous tubule is highly coiled so many cross sections in the one image. Has a central lumen with well defined basement membrane and myofibrils (transport). It contains the germinal epithelium (sperm cells) and Sertoli cells.
Outside the seminiferous tubules is the interstitium are the Leydig cells fibroblasts, collagen, capillaries and lymph vessels.
1 and 4 most important
Leydig cells structure and function
- Located in the interstitium
- Synthesis of testosterone
- Respond to LH
- Find the basal lamina and look for cell in interstitium
- Round cell, round nucleus, Reinke’s crystalloid
Sertoli cells structure and function
- Located in the seminiferous tubules
- Synthesis of hormones / proteins
- Respond to FSH
- Support cells for spermatogenesis
- Find the basal lamina and look for cell in seminiferous tubule. Appear indistinct in H&E
- Tall columnar cells, cytoplasmic extensions and tight junctions (blood testes barrier)
- Guide sperm towards lumen
- Phagocytosis
- Produces ABP (androgen binding protein), inhibin, AMH and oestrogens
- Androgen binding protein binds to testosterone,↓ lipophilic property, high levels testosterone is a pre-requisite for spermatogenesis, concentration of testosterone in ST»_space;> vs. systemic circulation
Cells of the testes
Spermatocytogenesis
Spermatogonia undergo Meosis I and Meosis II to produce 4 haploid spermatids
Spermiogenesis
Each spermatid becomes a highly differentiated spermatozoa
Spermatogenesis
- Spermatocytogenesis
- Spermiogenesis
About 2 months
Spermatozoa
Epididymis structure and function
- Highly coiled as it is a long length
- Process approx. 1 month
- Maturation
- Stabilisation of cell membrane
- Motility
- Tall columnar epithelium with basal nuclei
- Lumen contain clumps of spermatozoa
- Tall microvilli
- Absorb fluid
- Phagocytose
- Secretions
Ductus deferens
- Storage site (several months)
- Within the spermatic cord
- Thick muscular wall (3 layers)
- Tall columnar epithelium but with folds (stellate lumen)
- Widens at the end (ampulla) and receives fluid from the seminal vesicles
Route of sperm
- Seminiferous tubules
- Rete testes
- Ductus deferens
- Seminal vesicle
- Prostate
- Ejaculatory duct
- Bulbourethral glands to become seminal fluid
- Urethra
Seminal vesicles location and secretion
Location:
- Posterior aspect of the bladder
- Drains into the ampulla of the ductus deferens and denotes the beginning of the ejaculatory duct
Secretion:
- Secretes thick alkaline fluid with fructose and coagulation factors
- 60-70% of the final volume
Prostrate location, zones, secretion and components
Location
- Inferior aspect of the bladder
Zones are used for histological divisions
- Central 25%
- Transitional 5-10%
- Peripheral 65%
Secretion
- Thin milky fluid with citrate, zinc etc.
- Prostate specific antigen – liquefies coagulated ejaculate
- 20% of the final volume of semen
Components
- The prostate contains secretory glands that open into the urethra.
- These glands sit in a supportive stromal network of fibroblasts, collagen and smooth muscle.
- Septa extend internally into ill-defined lobes
- Ducts open into the urethral sinuses on either side of a longitudinal ridge called the urethra crest\
- Stroma (anteriorly placed) makes up rest of the gland (relatively non-secretory)
Ejaculatory duct location
Within the prostate the ejaculatory duct joins the urethra
Prostrate epithelium
The epithelium has folds and contains:
- tall columnar / cuboidal cells with pale cytoplasm (C)
- basal pale-staining nuclei are also present (B)
The secretory products include acid phosphatase, citric acid, fibrinolysin, amylase and other proteins
Bulbourethral glands location and secretion
Location
Pea-size glands embedded within the external urethral sphincter
It sits between the pelvic floor and the urogenital triangle
Drains into membranous urethra
Secretion
Secretes mucus
10% of the final volume of semen
Mechanism of penile erection
Penis histology
