Developmental Biology Flashcards
Genetic female sex is determined by the absence of
SRY gene
This sex determination is determined at the time of fertilization
Genetic sex
Single most consistent determinant of maleness
Presence of Y chromosome
This hypothesis states that one of the 2 copies of the X chromosome present in females is inactivated
Basis of sex chromatin test
Lyon hypothesis
Sex determination test that stains the hair strands with fluorescent stain
Used for large populations (Olympics) that ensures the individual joining the female division is a normal genetic female
Hair root test
Sex chomatin test looks for Barr bodies while Hair root test looks for
Y bodies
Most accurate method for sex determination
Karyotyping
This term describes the development of primary sex organs in response to genetic sex
Gonadal sex
At what week of gestation does the fetus have bipotential gonads?
4-6 weeks
This cell secretes testosterone which controls the development of the Wolffian duct and development of male external genitalia through DHT
Leydig cells
What hormone promotes the development of male external genitalia?
DHT
What hormone promotes the development of Wolffian duct into accessory structure?
Testosterone
This cell secretes anti mullerian hormone that cause the regression of the mullerian duct
Sertoli cell
The testis comes from this embryonic structure
Embryonic medulla
What happens to the embryonic cortex upon development of the male gonads?
Regresses
Formation of Sertoli cells happens during
6-7 weeks
Formation of Leydig cells occur during
8-9 weeks
Secretion of testosterone of Leydig cells occurs in response to what hormone
HCG
At what AOG is the definitive testes present and secretion of testosterone established?
9 weeks
At what AOG does the testes descend through the inguinal ring?
7-9 months
What hormone does the embryonic ovary secrete?
None
The embryonic cortex in female development proliferates to become
Ovaries
The ovaries reach maximal development at what AOG
20-25 weeks
In female gonad development the embryonic medulla regresses and forms the
Hilum of mature ovaries
When does female gonadal development start?
9 weeks when there is absence of signal for testis formation
This type of sex is determined by the regulation of gonadal sex of the differentiation of the genital apparatus
Phenotypic sex
Derivatives of the Wolffian duct
VESt
Vas deferens
Epididymis
Seminal vesicle
Derivatives of the Paramesonephric duct
Carey Mulligan (Mullerian) Fallopian tube Uterus Cervix Upper vagina
This hormone is required for conversion of testosterone to DHT
5 alpha reductase
Precursor of both external genitalia
Anlagen
Genital tubercle develops into these structures in the male and female external genitalia
Male- glans penis, corpus cavernosum, spongiosum
Female- clitoris and vestibular bulb
Urogenital folds become
Male- ventral shaft of penis
Female- labia minora
Labioscrotal/Genital swelling becomes
Scrotum and prepuce
Labia majora
The urogenital sinus becomes
Male urethra, Cowper, prostate gland
Female urethra, lower vagina, bartholin and skene glands
Transverse vaginal septum occurs when this structure fails to develop
Urogenital sinus
The growth of the labia to normal size requires this hormone
Estrogen
Control of gonadal function is mediated by these 2 gonadotropins
FSH
LH
Release of gonadotropins in males are in this manner
Tonic
Release of gonadotropins in females are in this manner
Cyclic
This type of sex is the establishment of gender role, identity and sexual orientation
Psychological sex
This type of error in sex determination occurs when there is an established defect in gametogenesis where chromosomes fail to separate and both go to one daughter cell during meiosis
Nondisjunction
Most common type of Nondisjunction that leads to complete absence of one sex chromosome and monosomy
Turner syndrome
Streaked ovary
Short stature
Shield chest
Coarctation of aorta
Turner syndrome
Meiotic nondisjunction that leads to testicular atrophy
Eunuchoid body shape
Tall, long extremities
Gynecomastia
Klinefelter
Genetic males whose target cells lack receptors for testosterone are feminized
Male pseudo hermaphroditism
Androgen insensitivity
Virilization of XX fetus
Ambiguous genitalia
Adrenal androgen overproduction
Congenital adrenal hyperplasia