male reproductive system · male reproductive system consists of testes genital ducts accessary sex...

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.