S2M3 development

  1. origin of urinary and genital systems
    - intermediate mesoderm
  2. mesonephric/ Wolffian duct
    • - develops into male internal structures
    • - SEED- seminal vesicles, epididymis, ejaculatory duct, ductus deferens
  3. sex specific morphological characteristics arise when
    • - week 7
    • - week 6 and earlier= indifferent stage
  4. paramesonephric/Muellarian duct
    • - form fallopian tube, uterus and upper 1/3 of the vagina
    • - form by invagination of coelomic epithelium
  5. primitive sex cords
    • - proliferation of coelomic epithelium over the genital ridge
    • - penetrates underlying mesenchyme
    • - incorporate with primordial germ cells(wk 6)
  6. SRY
    • - produces testis determining factor
    • - stimulates Sertoli and Leydig cell differentiation
  7. Sertolli cells
    • - derived from coelomic epithelium
    • - secrete anti-Muellarian hormone
  8. Leydig cells
    • - derived from original mesenchyme of genital ridge
    • - tunica abluginea also forms from mesenchyme
  9. Male primitive sex cords
    • - form medullary cords, which form rete testes and seminiferous tubules
    • - primordial germ cells become spermatogonia
  10. primitive sex cords in females
    • - develop into medullary cords and then degenerate
    • - replaced by ovarian medulla
    • - primordial gem cells= oogonia
  11. cortical cords
    • - 2nd generation of cords from surface epithelium in Females
    • - split into clusters = Follicular cells
  12. vestigial remnants of paramesonephric duct in males
    -utriculus prostaticus= uterus homolog

    - appendix testes= oviduct homolog
  13. mesonephric remnants in males
    • - appendix epididymis- from cranial end
    • - paradidymis- remnant of paragenital tubule on caudal pole of teste
  14. rete testis
    • - from medullary cords (primitive sex cords)
    • - connect straight tubules of seminiferous tubuls to efferent tubules of epididymis
  15. ductili efferentes
    - remaining parts of the excretory tubules of the mesonephros
  16. uterine canal
    • - fusion of caudal paramesonephric duct
    • - contact with primitive urogenital sinus causes vaginal plate (sinovaginal bulb) formation
  17. paramesonephric tubercle
    • - required for lower vagina formation
    • - sweeling of urogentital sinus from paramesonephric duct pushing on it
  18. sinovaginal bulb
    • - urogenital sinus and paramesonepric tubule prolieferation
    • - induced by contact of paramesonephric tubule contacting urogenital sinus
    • - forms vaginal plate which in turn forms the lower part of the vagina
  19. vestigial remnants of of mesonephros in females
    • - epophoron
    • - paroophoron
    • - Gartners cyst= paradidymis homolog
  20. sinus tubercle
    • - forms hymen in females
    • - forms seminal colliculus
  21. prostate
    • - outgrowth from prostatic urethra
    • - homologous to female paraurethral glands (of Skene)
  22. Bulbourethral glands
    • - outgrowths from urogenital sinus/ spngy urethra
    • - homologous female greater vestibular glands (of Bartholian)
  23. Seminal vesicle
    - outgrowth of mesonephric duct
  24. cloacal fold
    • - formed by mesenchyme migrating around cloacal membrane
    • - cranially it forms genital tubercle
    • - caudally it forms urethral and anal folds
  25. genital tubercle froms
    - glans and shaft(corpus cavernosa) of penis

    - clitoris
  26. definative urogenital sinus forms
    - penile urethra

    - vestibule
  27. urethral fold forms
    - corpus spongiosum

    - labia minora
  28. genital fold forms
    - scrotum

    - labia majora
  29. chorion
    • - fetal origin
    • - chorion frundosum- "bushy chorion"- on embryonic pole that expands and forms villi

    - chorion laeve- "smooth chorion"on abembryonic pole, degenerates by month 3
  30. cotyledons
    - compartments formed in placenta by projections of decidua septa (maternal origin)
  31. corpus luteum failure
    • - uterus produces enough progesterone to support itself at 10 weeks
    • - luteul/placental shift occurs between weeks 7-9, once the shift has occured the CL is no longer required to maintain pregnancy
    • - when estriol is seen it indicates fully functional placenta (L/P shift has occured)
  32. placenta components
    • - decidua basalis- maternal contribution
    • - chorion frundosum- fetal
  33. placental release
    - trigger PRL release=> lactation
  34. placental barrier
    • - impenetrable to protein hormones
    • - T3, T4 and unconjugated steroids can cross
    • -
  35. syncitiatrophoblast hormone production
    • - Progesterone
    • - Estrogen
    • - hCG
    • - somattotropin/placental lactogen
  36. twin sharing
    • - fraternal twins- nothing
    • - identical
    • a- early blastocyst- common placenta and chorionic cavity, seperate amniotic cavity
    • b- late blastocyst- common amniotic cavity included
Author
sweetlu
ID
144925
Card Set
S2M3 development
Description
S2M3 development
Updated