The development and sexual differentiation of the reproductive system Flashcards
what are the 4 parts of sexual development? [4]
1. Genetic sex
‐ Chromosomal composition: XX or XY
‐ Determined at fertilization, yet this doesn’t mean the organs have developed as male or female at this stage
- G_onadal development_
‐ Development of testes or ovaries
‐ Defined during embryonic development
3. Development of the sex‐specific internal ducts and external genitalia
‐ Hormone dependent
‐ Defined during fetal development
4.Secondary sex characteristics
‐ Defined at puberty
which of the following is determined in fetal development
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
which of the following is determined in fetal development
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
which of the following is determined at fertilisation
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
which of the following is determined at fertilisation
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
which of the following is determined during embryonic development
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
which of the following is determined during embryonic development
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
which of the following is determined during puberty
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
which of the following is determined during puberty
genetic sex
gondal development
development of sex-specific internal ducts and external genitalia
secondary sex characteristics
where do gonads appear at the start of their development? [1]
what does these ^ eventually become in the gonads? [1]
where do gonads appear at the start of their development? [1]
gonads appear as longitudinal gential ridges
what does these ^ eventually become in the gonads? [1]
eventually become ducts / tubules in the gonads
what is A & B?
A = genital ridges B = hindgut
explain the process primordial germ cell migration in the developing gonad xx
when and where does it occur? [2]
explain the process primordial germ cell migration in the developing gonad xx
i) when and where does it occur? [2]
* *primordial germ cell migration: moves to genital ridge at 4 weeks**
after primordial germ cells have migrated ot the genital ridges, which 3 cell types are found in the ridge? [3]
what are each of their functions? ^
1. primordial germ cell (just migrated) –> future gametes (spermatogonia and oogonia).
2. mesothelial cells –> seminiferous tubules and ovarian tubules (waiting to be activated)
3. mesenchymal cells –> leydig cells in males, stromal cells in female
what are the different types of mesenchymal cells in male and female? [2]
male = **leydig cells** female = **stromal cells**
what are the name of the genital / internal ducts in
males: [1]
females [1]
what are the name of the genital / internal ducts in
males: wolffian ducts
females: mullerian ducts
what do mullerian ducts give rise to ? [3]
what do wolffian ducts give rise to ? [3]
what do mullerian ducts give rise to ? [3]
uterus, fallopian tubes, cervix & upper 1/3 vagina
what do wolffian ducts give rise to ? [3]
vas deferens, seminal vesicles and epididymis
how does the body determine if you produce mullerian ducts or wolffian ducts? [2]
which hormones are secreted / what happens after this has happened to continue development of wolffian ducts? [2]
no hormonal input: develop mullerian ducts
hormanol input: wolffian ducts
then:
- SRY on Y chr encodes for testes-determining factor –> induces Leydig cells to produce testosterone
- *sertoli cells** in testes produce mullerian inhibitory factor: inhibits the formation of mullerian duct
what does DHT cause the production of? [3]
DHT, which will give rise to the male external genitalia (prostate, penis and scrotum).
what happens if have patients who’s leydig cells dont secrete testosterone?
Sometimes testosterone may not be secreted by Leydig cells.
- Patient presents as female with female external genitalia
- Primary amenorrhea
- No genital ducts/associated structures
- Undescended testes as genetically male XY
- Sertoli cells will still produce MHF which inhibits Mullerian duct, so you will have no uterus , fallopian tubes, cervix or upper vagina
when does differention into male / female occur?
week 6
week 7
week 8
week 9
week 10
when does differention into male / female occur?
week 6
week 7
week 8
week 9
week 10
have both the mullerian duct and wollfian duct up to 7 weeks - then differentation occurs
male development:
Wolffian duct persists to give rise to what? [3]
what happens to the Mullerian ducts? [1]
Wolffian duct persists to give rise to epididymis seminal vesicles and vas deferens
Mullerian duct will begin to degenerate.
female development:
what happens to mullerian ducts? [1] what do they turn into? [1]
what happens to mullerian ducts? [1]
close in and fuse into a continuum
what do they turn into? [1]
vaginal/ uteral canal
what can happen to mullerian duct to create anomolies?
double uterus
double vagina,
double uterus presenting to single vagina
sometimes only one duct persists, etc.
A double uterus or a bicornuate / unicornuate uterus results from? [2]
- Incomplete fusion of Mullerian ducts inferiorly
- Incomplete development of ducts
which hormone controls the formation of external genitalia?
testosterone
MIF
DHT
cHG
LH
which hormone controls the formation of external genitalia?
testosterone
MIF
DHT !!!
cHG
LH
formation of the external genitalia:
what does the labioscrotal swelling turn in (in male / female?) [2]
what does the urogenital folds turn into (male / female) [2]
what does the genital tubercle turn into? (male / female) [2]
what does the labioscrotal swelling turn in (in male / female?) [2]
labia majora (f)
scrotum
what does the urogenital folds turn into (male / female) [2]
ventral penis / penile urethra
labia minora
what does the genital tubercle turn into? (male / female) [2]
glans penis
glans clitoris
what is the position of the testes as they descend?
2nd month [1]
3rd month [1]
7th month? [1]
9 month? [1]
what is the position of the testes as they descend?
2nd month [1]
abdomen wall
3rd month [1]
migrate through abdomen - gubernaculum starts to develop and guide the testes down into the future scrotum
7th month? [1]
scrotum
9 month? [1]
9 months there should be a small area of gubernaculum
label A & B [2]
A: gubernaculum testis
B: vaginal process
during descent of testis:
what happens to transverse abdominis? [1]
what happens to processus vaginalis [2]
during descent of testis:
what happens to transverse abdominis? [1]
doesnt get carried through to testis
what happens to processus vaginalis [2]
- *should regress - if not turn is indirect inguinal hernias !**
- *turns into tunica vaginalis**
label A-D
A: transversalis fascia
B: transversus abdominis
C: internal oblique
D: External oblique
what is the name for when one or both of the testicles do not descend into the scrotum while the fetus is developing? [1]
what is an ectopic testes? [1]
Cryptorchidism
ectopic testis: where one of the testicles has not descended into the scrotum as normal, but instead has taken a different path and has descended through the abdominal cavity until it has settled in the pre-pubic area in the inguinal canal, instead of in the scrotum.
indirect / congenital hernia occurs because of a protrusion of an abdominal viscus into WHICH STRUCTURE? [1]
An indirect inguinal hernia is a congenital hernia, regardless of the patient’s age. It occurs because of protrusion of an abdominal viscus into an open processus vaginalis
describe relocation of the ovaries (move from where –> where?)
Move from superior lumbar region and relocate to the lateral wall of the pelvis
label A-E
A: Bladder
B: Vas deferens
C: seminal vesicles
D: prostate
E: ureters
which structures transverse the prostate? [2]
urethrea
ejaculatory duct
which part of the urethrea do the common ejaculatory ducts open into?
membranous urethra
spongy urethra
prostatic urethra
preprostatic urethra
which part of the urethrea do the common ejaculatory ducts open into?
membranous urethra
spongy urethra
prostatic urethra
preprostatic urethra
where is prostate in relation to bladder?
superior
inferior
lateral
medial
where is prostate in relation to bladder?
superior
inferior
lateral
medial
how many lobes does the prostate have? [3]
1 median
2 lateral
where does the suspenosry ligament run from (where to where)? [2]
where does the suspenosry ligament run from (where to where)? [2]
wall of the cavity –> uterus
label the different parts of the fallopian tube
which is the most common site of fertilisation in fallopian tube?
infundibulum
ampulla
isthmus
fimbrae
which is the most common site of fertilisation in fallopian tube?
infundibulum
ampulla
isthmus
fimbrae
what are the lumen called that surround the cervix? [1]
The lumen surrounding cervix divided into fornices – ant, post, and 2 lateral
name this structure [1]
ureters
