Embryology Flashcards
What are the structures that make up the male internal genitalia?
TestisDuct system- Epididymis- Ductus deferens/ vas deferens- UrethraSeminal vesiclesProstate glandBulbo-urethral glands
What are the structures that make up the male external genitalia?
Penis and Scrotum
What are the structures that make up the female internal genitalia?
OvariesDuct system- Fallopian tubes- Uterus- Cervix - Upper Part of the Vagina
What are the structures that make up the female external genitalia?
ClitorisLabia minoraLabia majoraVagina Vestibule
What are the male secondary sexual characteristics?
Increased body size compared to femalesCoarser skin and hair Different body composition and fat distributionFacial hair and male pattern baldnessCentral nervous effectsSmell
What are the female secondary sexual characteristics?
Decreased body size in comparison to malesSubcutaneous fat distributionHair Breast developmentCentral nervous effects
How is the development of the reproducive system similar initially?
Development gives rise to an indeifferent stage, producing a gonad and duct system which are idnetical. From here, hormones regulate the development into one of the two sexes.
What are the difference between structural and functional development?
Structural development occurs in utero whilst functional development and maturity occurs after birth at puberty, along with the development of the secondary sexual characteristics.
What is the gonad derived from?
The urogenital ridge which is a part of the intermediate mesoderm
What are primordial germ cells?
Cell which arise from an area near the allantois, which will migrate from the wall of the yolk sac, into the developing body of the embryo.
How do primordial germ cells move?
Start near the allantois, move retroperitoneally along the dorsal mesentery into the urogenital ridge and therefore the gonad. These will form the gametes for the next generation.
What gene is always expressed in males?
SRY gene– sex-determining region Y
What part of the gonad does the male genitalia develop from?
From the medulla
What does the medulla develop into in the male?
Horseshoe shaped testis cords (future seminiferous tubules) and a thick tunica albuginea.
What does the gonad develop into in females?
The gonad will then develop into an ovary and the duct system will form the fallopian tubes and the uterus and also the female external genitalia.
What part of the gonad do the ovaries develop from?
The cortex
What if the fate of the mesonephric ducts in males?
- Mesonephric ducts reach the urogenital sinus2. Ureteric buds develop from the mesonephric ducts and smooth musculature being to appear in the wall of the urogenital sinus which also begins to expand3. Both the ureteric buds and mesonephric ducts form separate openings in the urogenital sinus and the mesonephric ducts sat open due to the influence of male hormones as they will form the duct system of the male reproductive tract. 4. The prostate and prostatic urethra are formed again under the influence of male hormones from the Wolffian/mesonephric ducts.