Session 3 - Embryonic development of the reproductive tracts and development of the gametes Flashcards
What is gastrulation.
The process of cellular rearrangement which involves migration, invagination and differentiation of the epiblast. Orchestrated by the primitive streak
What is gastrulation.
The process of cellular rearrangement which involves migration, invagination and differentiation of the epiblast. Orchestrated by the primitive streak
What is the common caudal opening
The cloaca
What does th cloaca become
The urugenital sinus- the common opening for the reproductive ad urinary systems
When do male and female morphological characteristics develop
Seventh week
What is the key trigger in sexual dimorphism
Y chromosome
Contains the testis-determining gene also called SRY gene
Similarities between 2 systems
Germ cells
- migrate
- drive development of the gonad
Gonads
-both descend
Duct system
-forms internal genitalia
Differences between the 2 systems
Gonad
- medulla vs cortex
- tests vs ovaries
- androgens vs MIH vs neither
Duct system
- open vs closed
- mesonephric duct vas paramesonephric duct
What are primordial germ cells
Allocated shortly after gastrulation
Arise in the yolk sac and migrate into the retroperitoneum
give rise to gonads
What are the gonads and what are they derived from
Organs that produce sex cells and are derived from the
- mesothelium
- underlying mesenchyme
- primordial germ cells
What is the urugenital ridge
An area of intermediate mesoderm i the posterior abdominal wal that gives rise to teh embryonic kidney and gonad
What are primordial germ cells
Specialised population of cells that arise from the yolk sac and they develop soon after gastrulation has occurred
What does the presence of testes cause
They will produce androgens which then drive the development of the duct system in men; namely the epididymis and vas deferens by maintaining the mesonephric duct
the medulla develops
in the absence of testes what happens
Causes teh formation of the female internal genitalia - uterus Fallopian tubes and part f the vagina and the mesonephric duct regresses but the mullerian duct remains which doesn’t need stimulation unlike the mesonephric duct
the cortex dvelops
Why is there a gap in the communication within the abdominal cavity and the gonads in female anatomy
The mesonephric duct fuse with the testes so is continuous and ot open in teh peritoneum
However the paramesonephric duct is separate to the gonad and therefore teh 2 do to meet and there is no direct connection
What are the common elements of the undifferentiated external genitalia
Genital tubercle
Genital folds
Genital swellings
How does teh penis develop and why
The presence of the testes
Elongation and fusion f the genital folds
how does the scrotum develop
Fusion of the genital swellings
How do th testes develop
An area of the periotoneum pinches off ( processus vaginalis) to descent first and then the gubernaculum and testis follow behind all th way to the scrotum
Descent of ovaries
Processes vaginalis pinches off and the gubernaculum follows however it states in the pelvis because of eh physical barrier of te developing uterus
What does the gubernaculum remain as i women
Round ligament
ovarian ligament
What is the mesonephric duct als known as
Wolffian duct - male = wolf
What is paramesonephric duct also known as
Müllerian duct - m= mother
what does the genital tubercle ddvelop into in males
corpus spingiosum
corpus cavernosum
glans penus
