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origin of urinary and genital systems
- intermediate mesoderm
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mesonephric/ Wolffian duct
- - develops into male internal structures
- - SEED- seminal vesicles, epididymis, ejaculatory duct, ductus deferens
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sex specific morphological characteristics arise when
- - week 7
- - week 6 and earlier= indifferent stage
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paramesonephric/Muellarian duct
- - form fallopian tube, uterus and upper 1/3 of the vagina
- - form by invagination of coelomic epithelium
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primitive sex cords
- - proliferation of coelomic epithelium over the genital ridge
- - penetrates underlying mesenchyme
- - incorporate with primordial germ cells(wk 6)
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SRY
- - produces testis determining factor
- - stimulates Sertoli and Leydig cell differentiation
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Sertolli cells
- - derived from coelomic epithelium
- - secrete anti-Muellarian hormone
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Leydig cells
- - derived from original mesenchyme of genital ridge
- - tunica abluginea also forms from mesenchyme
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Male primitive sex cords
- - form medullary cords, which form rete testes and seminiferous tubules
- - primordial germ cells become spermatogonia
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primitive sex cords in females
- - develop into medullary cords and then degenerate
- - replaced by ovarian medulla
- - primordial gem cells= oogonia
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cortical cords
- - 2nd generation of cords from surface epithelium in Females
- - split into clusters = Follicular cells
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vestigial remnants of paramesonephric duct in males
-utriculus prostaticus= uterus homolog
- appendix testes= oviduct homolog
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mesonephric remnants in males
- - appendix epididymis- from cranial end
- - paradidymis- remnant of paragenital tubule on caudal pole of teste
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rete testis
- - from medullary cords (primitive sex cords)
- - connect straight tubules of seminiferous tubuls to efferent tubules of epididymis
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ductili efferentes
- remaining parts of the excretory tubules of the mesonephros
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uterine canal
- - fusion of caudal paramesonephric duct
- - contact with primitive urogenital sinus causes vaginal plate (sinovaginal bulb) formation
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paramesonephric tubercle
- - required for lower vagina formation
- - sweeling of urogentital sinus from paramesonephric duct pushing on it
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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
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vestigial remnants of of mesonephros in females
- - epophoron
- - paroophoron
- - Gartners cyst= paradidymis homolog
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sinus tubercle
- - forms hymen in females
- - forms seminal colliculus
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prostate
- - outgrowth from prostatic urethra
- - homologous to female paraurethral glands (of Skene)
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Bulbourethral glands
- - outgrowths from urogenital sinus/ spngy urethra
- - homologous female greater vestibular glands (of Bartholian)
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Seminal vesicle
- outgrowth of mesonephric duct
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cloacal fold
- - formed by mesenchyme migrating around cloacal membrane
- - cranially it forms genital tubercle
- - caudally it forms urethral and anal folds
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genital tubercle froms
- glans and shaft(corpus cavernosa) of penis
- clitoris
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definative urogenital sinus forms
- penile urethra
- vestibule
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urethral fold forms
- corpus spongiosum
- labia minora
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genital fold forms
- scrotum
- labia majora
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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
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cotyledons
- compartments formed in placenta by projections of decidua septa (maternal origin)
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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)
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placenta components
- - decidua basalis- maternal contribution
- - chorion frundosum- fetal
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placental release
- trigger PRL release=> lactation
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placental barrier
- - impenetrable to protein hormones
- - T3, T4 and unconjugated steroids can cross
- -
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syncitiatrophoblast hormone production
- - Progesterone
- - Estrogen
- - hCG
- - somattotropin/placental lactogen
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twin sharing
- - fraternal twins- nothing
- - identical
- a- early blastocyst- common placenta and chorionic cavity, seperate amniotic cavity
- b- late blastocyst- common amniotic cavity included
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