Session 1 Flashcards
What are the components of the male internal genitalia?
Testes Duct system (vas deferens, epididymis) Seminal vesicles Prostate gland Bulbs-urethral glands
What are the components of the female internal genitalia?
Ovaries Duct system (Fallopian tube, uterus, cervix, vagina)
What are the components of the male external genitalia?
Penis
Scrotum
What are the components of the female external genitalia?
Vagina Vestibule Labia minora Labia majora Clitoris
Give examples of secondary sex characteristics in males.
Increased body size (rel to ♀) Body composition & fat distribution Hair & skin Facial hair Male pattern baldness Central nervous effects Smell
Give examples of secondary sex characteristics in females.
Smaller body size (rel to ♁) Subcutaneous fat distribution Hair & skin Breast development Central nervous effects
What tissues give rise to the indifferent gonads?
Intermediate mesoderm
Primordial germ cells (extragonadal)
Where do the primordial germ cells arise?
Yolk sac (they migrate into the retroperitoneum along the dorsal mesentery)
Why are the primordial germ cells separated from the somatic cell line so early in development?
To prevent them from differentiating
Which gene is responsible for the development of the male and where is it found?
SRY gene found on the Y chromosome
Absence of a Y chromosomes drives the development of the female
What is the name given to the thick outer covering of the male gonad, that is not present in the female?
Tunica albuginea
What are the mesonephric and paramesonephric ducts also known as?
MND: Wolffian duct
PMND: Müllerian duct
During development, what is the name of the structure that marks the end of the urinary, reproductive and gastrointestinal tracts?
Cloaca
Which germ layers contribute to the formation of the vagina?
Upper 1/3: intermediate mesoderm
Lower 2/3: Endoderm
In an XY embryo, what supports the development of the mesonephric (Wolffian) duct?
Androgen secreted by the testes
In an XY embryo, what causes the degeneration of the paramesonephric (Müllerian) duct?
Müllerian inhibitory substance secreted by the testes
Explain the effects of gonadal hormones on the XX embryo.
Ovaries develop
No androgen produced, hence the Wolffian ducts degenerate
No Müllerian inhibitory substance produced, hence the Müllerian ducts develop
What are the basic components of the external genitalia during the indifferent stage?
Genital tubercle
Genital folds
Genital swellings
What drives the masculinisation of the external genitalia?
Testis-derived androgen (dihydrotestosterone)
Approximately how many gametes will a female produce in her lifetime?
400
Approximately how many gametes will a male produce per day?
200 million
After meiosis 1 and 2, how many mature oocytes are present?
1 (the other three daughter cells become polar bodies)