MALE REPRODUCTIVE SYSTEM
DR.M.SARWAR ZIA
Assistant professor anatomy
RMU
OVERVIEW
Male reproductive system consists of
Testes
Genital ducts
Accessary sex glands
penis
Functions of testes:-
Production of spermatozoa
Secretion of testosterone
Actions of testosterone
Actions of dihydrotestosterone
Genital ducts & accessary sex glands
Testes
Testes derived from three sources
Intermediate mesoderm
Mesodermal epithelium
Primordial germ cells
Decent of testes
At approximately 26 weeks testes descendGubernaculum Cryptorchidism Orchioplexy Maintenance of temperature of testes in the
scrotum Countercurrent heat exchange mechanism Sweating Dartos muscle Cremaster reflex
Testes
Tunica albuginea
Tunica vasculosa
Mediastinum testes
Testicular lobules (250)
Seminiferous tubules
Interstitial loose connective tissue
Interstitial cells (Leydig)
Straight tubules
Rete testes
Seminiferous tubules
Each Seminiferous tubule is
50 cm long (30 to 80 cm)
150 to 250µm in diameter
Seminiferous epithelium
Tunica propria (peritubular tissue)
Spermatogenic cells
Sertoli cells
Sertoli cells
Structure
Sertoli cells junctional complexes
Sertoli cell to Sertoli cell junctional complexes
Sertoli cell to Spermatid junction
Sertoli cell to basal lamina
Sertoli cells functions Provide support ,protection and nutrition to
developing spermatogenic cells Exocrine and endocrine secretion Androgen binding protein(ABP) Inhibin Mullerian inhibiting substance (MIS) Phagocytosis Establish blood testis barrier which protects the
haploid male germ cells from immune system of the body
Blood – testes barrier
Tunica propria
• Also called peritubular tissue
• Multilayered connective tissue which lacks fibroblast
• Composed of 3 to 5 layers of myoid cells and collagen fibrils
• Excessive thickening in early life is associated with infertility
Interstitial cells (Leydig)
Large and polygonal
Eosinophilic
Contains lipid droplets
Lipofuscin pigments
Have all features of steroid secreting cells
Secrete the testosterone
Spermatogenesis
A process by which spermatogonia develop into mature sperms
Begins shortly before puberty
Continues throughout the life
Phases of spermatogenesis
Spermatogonial phase
Spermatocyte phase (Meiosis)
Spermatid phase (spermiogenesis)
Spermiogenesis
A process by which spermatids undergo extensive remodeling and transform into spermatozoa
Spermiogenesis include
Formation of acrosome
Condensation and elongation of nucleus
Development of flagellum
Loss of much of the cytoplasm
Phases of spermiogenesis
Golgi phase
Cap phase
Acrosome phase
Maturation phase
Structure of mature sperm
Mature human sperm 60µm
parts
• Head 5x3x1 µm
• Tail
Neck (connecting piece)
Middle piece 7µm
Principal piece 40µm
End piece 5µm
Structure of mature sperm
Intratesticular ducts
Straight tubules
Rete testes
Straight tubules
Initial part is lined by sertoli cells
Main segment is lined by simple cuboidal epithelium
Outer to basal lamina is loose CT
Rete testis
Lined by simple cuboidal epithelium
Testis (low magnification)
Testis (higher magnification)
Extratesticular duct system
Efferent ductules
Epididymis
Ducts deferens
Ejaculatory duct
urethra
Efferent ductules
About 20 in number
Derived from mesonephric tubules
Connects the rete testis with duct of epididymis
Coni vasculosae (6 to 10)
Efferent ductules are coiled about 15 to 20 cm long
Efferent ductules
Lined by pseudostratified columnar epithelium
Groups nonciliated cuboidal cells alternating with ciliated columnar cells
Thin circular layer of smooth muscle out side basal lamina
Interspersed among the smooth muscle are elastic fibers
Epididymis
Crescent shaped organ
Measures 7.5 cm long
Location
Measurements 4-6m
Parts of epididymis
Head
Body
Tail
Functions of Epididymis
Storage of spermatozoa
Transportation of spermatozoa towards the ducts deferens
Reabsorption of most of the fluid that leaves the testis
Spermatozoa acquire the motility in the epididymis
Phagocytosis of degenerated sperms and extra cytoplasm
Spermatozoa become more cylindrical in duct of epididymis
Epididymis
Lining of Duct of epididymis Principal cells Basal cells Outer to epithelium are
circularly arranged smooth muscles in head and body
In the tail three layers of smooth muscles
Outer the smooth muscles is loose connective tissue
Epididymis
Ductus(Vas) deferens
Longest part genital duct system
Course
Ampulla of vas deferens
Ejaculatory duct
Structure
Lumen narrow longitudinally folded
Pseudostratified columnar epithelium
Sparse Stereocilia Lamina propria rich in
elastic fibers Three muscle layers(1 to 1.5
mm) Adventitia Loose CT In ampulla mucosa shows
extensive folding Muscle layer become thin Ejaculatory duct no smooth
muscle (Jonquiere's)
Ampulla of ductus deferens
Ejaculatory ducts
Accessary sex glands
• Paired Seminal vesicle
• Prostate gland
• Paired Bulbourethral glands
Seminal vesicles
Paired elongated highly folded tubular exocrine glands
Measurement 15 cm long
Location
Seminal vesicles
Structure:-Mucosa Pseudostratified
columnar epithelium Lamina propria Smooth muscles Inner circular Outer longitudinal Adventitia is formed by
fibroelastic connective tissue
Seminal vesicles
Seminal vesicles
Prostate
Largest accessary sex gland
Location
Measurements 2cmx3cmx4cm
Weight 20 grams
Consists of 30 to 50 branched tubuloalveolar glands
Arrangement
Mucosal glands 5%
Submucosal glands 25%
Main glands (Peripheral) 70%
Prostate
Openings of prostate glands
Prostate
Zones of prostate=-
Transition zone
Central zone
Peripheral zone
Clinical correlation
Benign prostatic hypertrophy (BPH)
Transition zone of prostate is involved
Is present in 50 % males above the age of 50 years
Is present in 95 % males above the age of 70 years
Leads to compression of urethra causing difficulty in micturition
Prostatic cancer
Peripheral zone of prostate is involved
One of most common form of cancer in man
Prostatic specific antigen (PSA)
Prostatic acid phosphatase (PAP)
Normal level of PSA 4ng/ml
If level is 4 to 10 ng/ml the risk of cancer is 25%
If level is above 10 ng/ml the risk of cancer is isgreater than 67%
Microscopic structure of Prostate gland
Compound tubuloalveolar gland lined by simple columnar or pseudostratified columnar epithelium
Capsule
Septa
Indistinct lobes
Fibromuscular stroma
Corpora amylacia (prostatic concretions)
Corpora amylacea (prostatic concretions)
Small spherical concretions
0.2 to 2 mm in diameter Contains mainly
deposited glycoproteins and sulfated Glycosaminoglycans particularly keratin sulfate
Number and size increase with age
No physiological and clinical significance
Bulbourethral (Cowper’s) glands
Paired glands 3 to 5 mm in diameter Located in urogenital
diaphragm Ducts open in the initial
part of penile urethra Compound tubuloalveolar
gland Secretions are mucus in
nature Capsule lobules
Secretory acini are lined by simple columnar epithelium
Septa rich in smooth muscles
References
• Histology A Text And Atlas
Michael H Ross 5th Edition.
• Basic Histology Text and Atlas by Luiz Carlos Junqueira 12th Edition
• Medical histology by Liaq Hussain Siddiqui 5th
Edition
• Google Search results for images.
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