Development of male reproductive organs By Prof. Dr. Ansari (for MBBS Semester II) Wednesday, April 26, 2017Wednesday, April 26, 2017

Objectives Development of testis, epidydimis, vas deferens. Prostate, seminal vesicle, penis and scrotum developments. Congenital anomalies of internal & external genitalia. Wednesday, April 26, 2017Wednesday, April 26, 2017

The primordial germ cells arise from the yolk sac/endoderm and migrate into the intermediate mesoderm Wednesday, April 26, 2017Wednesday, April 26, 2017

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. Wednesday, April 26, 2017Wednesday, April 26, 2017

Wednesday, April 26, 2017Wednesday, April 26, 2017

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. Wednesday, April 26, 2017Wednesday, April 26, 2017

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. Wednesday, April 26, 2017Wednesday, April 26, 2017

Wednesday, April 26, 2017Wednesday, April 26, 2017

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. Wednesday, April 26, 2017Wednesday, April 26, 2017

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. Wednesday, April 26, 2017Wednesday, April 26, 2017

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). Wednesday, April 26, 2017Wednesday, April 26, 2017

Prostate & bulbourethral glands These glands are derived from the sinovaginal bulb. The penis and scrotum develops from the median genital tubercle and labioscrotal swellings. Wednesday, April 26, 2017Wednesday, April 26, 2017

Development of the external genitalia Wednesday, April 26, 2017Wednesday, April 26, 2017

Wednesday, April 26, 2017Wednesday, April 26, 2017

Wednesday, April 26, 2017Wednesday, April 26, 2017

Wednesday, April 26, 2017Wednesday, April 26, 2017

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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 Wednesday, April 26, 2017Wednesday, April 26, 2017

Congenital anomalies Ectopic testis/undescended testis Hypospadias Epispadias Wednesday, April 26, 2017Wednesday, April 26, 2017

Epispadias Wednesday, April 26, 2017Wednesday, April 26, 2017

Hypospadias Wednesday, April 26, 2017Wednesday, April 26, 2017

Bifid scrotum Wednesday, April 26, 2017Wednesday, April 26, 2017

2 months-------3 months of IUL. DESCENT OF TESTIS Wednesday, April 26, 2017Wednesday, April 26, 2017

Descent of testis 7 month 9 month Gubernaculum testis Wednesday, April 26, 2017Wednesday, April 26, 2017 Gubernaculum testis

Ectopic testis/undesceded testis Wednesday, April 26, 2017Wednesday, April 26, 2017