Embryogenesis of the Pituitary Gland and the Male or Reproductive System Flashcards
What are the 3 types of embryonic germ layers?
Endoderm, mesoderm, ectoderm
What stems from endoderm germ layer?
Digestive system, respiratory system, most glands
What stems from mesoderm germ layer?
Reproductive system
- gonads (male or female)
- uterus, cervix, part of the vagina
- epididymis, ductus deferense
- accessory sex glands
What stems from the ectoderm?
nervous system - hypothalamus, pituitary gland
reproductive tract - portions of vaginal and vestibule, penis, vahina
What part of the pituitary gland comes from neurohypophysis?
Posterior
Neural tissue developed from infundibulum
What part of the pituitary gland comes from adenohypophysis?
Anterior
Glandular tissue developed from Rathke’s pouch
What is the sella turica?
Protective cavity around pituitary
Where do primordial germ cells migrate to and from?
Inner yolk sac –> midgit –> mesentary –> genital/gonadal ridge
What is the function of PGC’s?
- colonize genital ridge
- stimulate connective tissue proliferation
- form compact strands of tissue (primitive sex cords)
- cause genital ridge to enlatge
Pronephros
Pronephric kidney
non-function, remnant of lower animals
Mesonephros
Mesonephric kidney
functional, bilateral, intermediate kidney
What are the mesonephric ducts also called?
Wolffian duct
Metanephros
Metanephric kidney
Final renal form - adult
Paramesonephric ducts
What is male differentiation controlled by?
SRY protein
What does TDF do?
Acts on sex cords of primitive gonad – stimulate male sertoli cells / testis development
What do sertoli cells secrete?
Anti-mullerian hormone (AMH) and dihydrotestosterone
What is Desert Hedgehog gene?
Causes fetal laydig cells to differentiate and produce
- testosterone –> male system/ wolfiian ducts
- dihydrotestosterone –> secondary sex characteristics, penis, scrotum
What is combined function of AMH and testosterone?
causes paramesonephric ducts (Mullnerian ducts) to degenerate
Rete tubules adult version
Rete testis
Mesonpehric tubules adult version
Efferent ducts
Mesonephric duct adult version
Epididymis and ductus deferens
Sex cords adult version
Seminiferous tubules
What are the 3 phases of testis descent?
- growth and elongation of the fetal body away from the testis
- rapid growth of the extra abdominal gubernaculum
- shrinkage of the gubernaculum within the scrotum
What is discendin?
factor produced by testis that promotes growth of gubernaculum
Bilateral cryptorchidism
results in sterility but still produce testosterone
Unilateral cryptochidism
Normal secondary sex characteristics and sexual behavior
What happens when there is no TDF?
cells form primitive follicle cells (not sertoli cells)
What happens when there is no EMH from sertoli cells?
leydig cells cant produce testosterone
no male development
mesonephric duct (wolffian duct) and tubules regress. Causes paramesonephric ducts to develop into most of repro travt
What is anterior (cranial) vaginal derived from?
Mesoderm
What is posterior (cuadal) vagina derived from?
Ectoderm
Paramesoneprhic duct adult version
oviduct and uterus
Regression of sex cords adult version
primordial follicles of ovary
Coelomic epithelium adult version
cortex of ovary
Fused paramesonephric ducts adult version
cervix, uterine body, and anterior vagina
Urogenital sinus adult version
Posterior vaginal and vestibule
Genital fold adult version
broad ligament
What are the 3 types of hermaphrodites
- true hermaphrodite
- male pseudohermaphrodite
- female pseudohermaphrodite (free martin)
