1. Development of male reproductive organs
By Prof. Dr. Ansari
(for MBBS Semester II)
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2. Objectives Development of testis, epidydimis, vas deferens.
Prostate, seminal vesicle, penis and scrotum developments.
Congenital anomalies of internal & external genitalia.
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3. The primordial germ cells arise from the yolk sac/endoderm and migrate into the intermediate mesoderm
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4. The intermediate mesoderm
It will going to form the testis/ovary.
A hormone called TDF (Testis determining factor), is released from Sertoli cells.
This hormone suppresses the development of paramesonephric duct/Mullerian duct.
The primordial sex cells which carry XY chromosome that settle in the intermediate mesoderm will differentiate into testis.
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6. The genital ridge
It is the intermediate mesoderm thickening medial to the embryonic kidney development that form the genital ridge.
The primordial sex cells migrate and settle down in the genital ridge.
The SRY gene present in the Y-chromosome induces the cells of the genital ridge to form sertoli cells.
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7. Once Sertoli cells are formed
In the medulla of the genital ridge, it secretes the AMF (Anti-Mullerian Factor)
This represses the female developmental path way.
It also stimulate the intermediate mesoderm to differentiate into Leydig cells.
These cells will secrete the testosterone hormone.
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9. If the primordial germ cells carry
XX chromosomes then on migration to the intermediate mesoderm/genital ridge will not differentiate in to the testicular cords.
The primordial sex cells will multiply in the cortex and form the follicles.
The absence of AMF will make the paramesonephric duct to develop and form the female pathway of development.
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10. In the absence of testosterone
The Mesonephric duct degenerates.
The Mullerian duct grows and will form the fallopian tubes, uterus and upper 1/3rd of vagina.
The lower 2/3rd of vagina is formed by the Sinovaginal bulb.
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11. The mesonephric duct
It forms the epidydimis, vas deferens, Seminal vesicles,& ejaculatory ducts. (1,2,3).
On epidydimis it remains as appendix of epidydimis (5).
Where as the appendix of testis is the remains of paramesonephric duct (4).
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12. Prostate & bulbourethral glands
These glands are derived from the sinovaginal bulb.
The penis and scrotum develops from the median genital tubercle and labioscrotal swellings.
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13. Development of the external genitalia
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18. EMBRYONIC DERIVATIVES
Genital tubercle = Penis
Labioscrotal swellings = Scrotum
Urethral groove closure = spongy urethra
Mesonephric duct = epidydimis+vas deferens+seminal vesicle
Sinovaginal bulb=prostate+bulbourethral glands, membranous urethra
Paramesonephric duct= prostatic utricle+appendix of testis
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19. Congenital anomalies Ectopic testis/undescended testis Hypospadias
Epispadias
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20. Epispadias
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21. Hypospadias
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22. Bifid scrotum
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23. 2 months-------3 months of IUL. DESCENT OF TESTIS
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24. Descent of testis 7 month 9 month Gubernaculum testis
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Gubernaculum testis

25. Ectopic testis/undesceded testis
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