Male Reproductive System Histology Flashcards
What becomes the Wolffian duct?
Mesonephric duct
Where does the Mullerian duct develop?
Beside Wolffian duct
What gene drives testis development?
Sry gene, on Y chromosome
What does anti-Mullerian hormone do?
Causes Mullerian duct to degenerate
What effect does testosterone have on the developing male reproductive tract?
Differentiation of male reproductive organs
What is cryptorchidism?
Problem in testis descent
What are the histological changes seen in cryptorchidism?
Hypoplasia of Leydig cells
Smaller seminiferous tubules
Fewer spermatogonia
Peritubular fibrosis
Which cancer are you at a greater risk of with cryptorchidism?
Testicular cancer
How many lobules make up the testis?
250
How many seminiferous tubules are contained in each lobule of the testis?
1-4
Where do the seminiferous tubules end?
As straight tubule = tubulus erectus
At mediastinum
What does the tubulus erectus connect to?
Rete testis = anastomosing channel system
What are the layers of the testis?
Outermost: tunica vaginalis - Extension of abdominal peritoneum, taken during descent Tunica albuginea - Dense connective tissue capsule - At posterior surface thickens and projects inward = mediastinum testis Innermost: tunica vasculosa - Loose, connective tissue - Contains blood vessels
Where does spermatogenesis occur?
At seminiferous epithelium
What is in between the seminiferous tubules?
Interstitium
What are the cells within the seminiferous tubules?
Sertoli cells = supporting cell lineage
Spermatogenic cells = germ cells
What are the cells surrounding the seminiferous tubules?
Peritubular myoid cells = smooth muscle-like cells
What are the cells in the interstitium?
Leydig cells = make testosterone
Blood vessels
Stromal cells
When spermatids are released into the lumen, are they motile?
No, still non-motile
Need substances from epididymis to become motile
What are the four phases of spermiogenesis?
- Golgi phase = spermatid starts to form head (acrosome) and DNA becoming highly condensed
- Cap phase = formation of acrosomal cap
- Acrosomal phase = 1 of centrioles elongates to become tail
- Maturation phase = remaining cytoplasm and organelles removed by phagocytosis of Sertoli cells
- Elongated, non-motile spermatids released into lumen > epididymis
What is contained within the acrosomal cap, and why is this needed?
Contains hydrolases
Needed for penetration into ovum
What limits sperm production?
Number of Sertoli cells
What sets ub the blood-testis barrier?
Sertoli-Sertoli cell junctional complex = tight junctions
What sort of nucleus do Sertoli cells have?
Elongated nucleus
What shape are Leydig cells?
Polygonal
What do Leydig cells often contain?
Lipid droplets
Reinke’s crystals
What are Reinke’s crystals?
Cytoplasmic crystals Rod shaped Probably proteins Unknown function Increase with age
Describe the peritubular myoid cells
Smooth muscle-like
Pump sperm into epididymis
2-3 layers around tubules
Together with Sertoli cells, produce basement membrane
Describe the efferent ducts
Up to 12
Join at head of epididymis to form ductus epididymis
Undulating border - stellate in cross-section
Lined by pseudostratified columnar epithelium with ciliated and non-ciliated cells
Reabsorb >90% of rete testis fluid to concentrate sperm
How long is the epididymis?
5 m
What are the segments of the epididymis?
Capus = head Corpus = body Caudal = tail
What epithelial cells line the epididymis?
Pseudostratified columnar epithelium with stereocilia
What are the functions of the epididymis?
Sperm transport
Sperm maturation
Sperm storage
What cell types make up the vas deferens?
Thick layer of smooth muscle cells: 3 layers
- Circular layer sandwiched between 2 longitudinal layers
Inner pseudostratified columnar epithelium with tall stereocilia
What is the shape of the lumen of the vas deferens in cross-section?
Stellate
What cell types make up the seminal vesicel?
Tube lined with pseudostratified columnar epithelium
Smooth muscle in main subcapsular wall and around internal convolutions
What does the seminal vesicle do?
Secrete alkaline, viscous fluid
- Neutralisation of acidic female reproductive tract environment
Contributes to sperm motility and viability
What are corpora amylacea in the glandular lumen of prostate?
Small concretions seen with increasing age
Mixture of
- Debris of degenerate cells
- Thickened secretions
What are the three zones of the prostate?
Peripheral
Central
Transitional
What are the elements that make up the prostate?
Glandular elements - Mucosal - Submucosal - Main prostatic gland Tubulo-alveolar elements Basal cells Secretory columnar cells
What are the types of glands within the bulbourethral glands?
Tubular
Alveolar type
What is the epithelium lining the bulbourethral glands?
Tall columnar
What are the three cylinders of erectile tissue that make up the penis?
2 corpora cavernosa surrounded each by tunica albuginea
Corpus spongiosum surrounded by thin layer of connective tissue with some smooth muscle fibres
- Encloses penile urethra
Each cylinder contain trabecular network of veins surrounded by
- Collagen
- Elastic fibres
- Smooth muscle cells
