3.6 Embryology of the reproductive organs Flashcards
What does the embryoblast give rise to?
The embryo
What does the embryoblast split into?
The bilaminar germ disc comprising of the epiblast and hypoblast
What are the three layers of the trilaminar germ disc
ectoderm
mesoderm
endoderm
What are the sections of the mesoderm and what will they form?
Splanchnic: heart
Intermediate: urogenital
Paraxial: exoskeleton and skeletal muscles
When do the undifferentiated gonads form?
Week 6
What 3 cell types are found in the testis?
Spermatogenic cells in the seminiferous tubules
Sertoli cells in seminiferous tubules
Leydig cells between the seminiferous tubules
What forms the epididymis, vas deferens and what degenerates to form the male testis?
Mesonephric tubules as efferent ductules to the epididymis
Mesonephric duct as vas deferens
Mullerian duct degenerates
What covers the testis?
double layered peritoneum and the cremaster muscle (internal oblique)
What occurs at the 4th week?
Development of the mesenephros and mesonephric ducts
What happens at the 5th-6th weeks?
Formation of indifferent gonads, migration of primordial germ cells and formation of mullerian ducts
What happens at week 7 for males?
SRY gene causes testis determining factor to be released and the medullary cord develops
Sertoli cells secrete anti mullerian hormone and the mullerian ducts degenerate
Leydig cells secrete testosterone and the mesonephric ducts develop into male genital ducts causing the formation of male genitalia
What happens at week 7 form females?
no SRY gene allows the cortical cord to develop
no AMH allows the mullerian ducts to develop into fallopian tubes, vagina and uterus
No testosterone means the mesonephric ducts will degenerate and female external genitalia will form
