1 - Repro - Origin of the Sexes Flashcards
From which layer of the bilaminar disc does do the primordial germ cells develop from?
Epiblast
What determines whether the primordial gonads develop into ovaries or testes?
Whether they are colonised by a germ cell with XX or XY chromosomes
What part of the primordial gonad does a germ cell with XX chromosomes colonise?
Cortex
What part of the primordial gonad does a germ cell with XY chromosomes colonise?
Medulla
Name the gene expressed by Sertoli cells, which drives male development:
SRY gene
Which cell expresses the SRY gene which drives Male development?
Sertoli cells
What is the average length of the vas deferens?
~ 30-45 cm
Which part of the male genitalia develops from the urogenital sinus?
Prostate
Bulbourethral glands
Urethra
Which part of the male genitalia develops from the mesonephric duct?
Epidydimis
Vas deferens
Seminal vesicles
Which part of the female genitalia develops from the urogenital sinus?
Vagina
Which part of the female genitalia develops from the paramesonephric ducts?
Fallopian tubes
Uterus
Cervix
List some secondary female sex characteristics:
- Hair growth
- Breast development
- Subcutaneous fat redistribution (around hips, buttocks and thighs)
- Elbows hyperextend 5-8’ more than males
List some male secondary sex characteristics:
- Hair growth
- Change in body composition: more muscle:fat
- Enlargement of larynx = voice deepens
- Larger hands, feet and nose
- Broadening of shoulders and chest
What is another name for the Wolffian ducts?
Mesonephric ducts
What is another name for the Mullerian ducts?
Paramesonephric ducts
Name the ducts from which the male genitalia develop from:
Mesonephric/Wolffian ducts
Name the ducts from which the female genitalia develop from:
Paramesonephric/Mullerian ducts
What ensures the regression of the Mullerian ducts for male development?
Mullerian Inhibitory Hormone (MIH) release from Sertoli cells
What substance is secreted by Sertoli cells causing the regression of the Mullerian ducts?
Mullerian Inhibitory Hormone (MIH)
What substance supports the development of the Mesonephric/Wolffian ducts?
Androgens
Name the parts of the external genitalia of an indifferent embryo:
- Genital tubercle
- Genital swelling
- Genital fold
- Urethral fold
What parts of the female external genitalia form from the urethral folds and genital swelling?
Labia minora
Labia majora
What part of the female external genitalia form from the genital tubercle?
Clitoris
Which hormone is vital for the closing of the urethral folds, for the development of the penis?
Dihydrotestosterone
Which part of the male external genitalia form from the genital swelling?
Testes
Which part of the male external genitalia form from the genital tubercle?
Glans penis
Name the remnant of the gubernaculum:
Males = Scrotal ligament Females = Round ligament of the uterus + Ovarian ligament
Describe the location from where the testes and ovaries arise:
Upper lumbar area of posterior abdominal wall
In approx. which month of development do the testes reach the iliac fossa?
~ 3rd month
In approx. which month of development do the testes enter the inguinal canal?
~ 7th month
