Intersex Flashcards
genetic sex
sex as indicated by the presence of XX (female) or XY (male) chromosomes
phenotypic sex
the internal and external morphology of each sex, and results from differences in gene expression
gonadal sex
sex as indicated by the presence of ovaries (female) or testes (male)
behavioural/psychological sex
how the person self identifies i.e. gender identity
indifferent stage
- first few weeks of development where male and female structures are the same
mesonephric kidney
primordial kidney that degenerates until metanephric kidney is formed, and is a precursor for some of the male structures; it is drained by the mesonephric duct
mesonephric duct
Wolffian duct; can develop male tubework
mullerian duct
develops into the female reproductive tract
indifferent gonads
the undifferentiated gonads of the early mammalian fetus, which will eventually develop into either testes (center) or ovaries (cortex)
urogenital sinus
point where the urogenitary systems coalesce
- sinus forms lumen of penile urethra
- when urogenital folds develop over top of sinus, will develop into tube-like structure that leads out and opens at genital tubercle
- in females, this persists as an open sinus which will develop into the vestibule
cloaca
common opening for digestive, urinary, and reproductive tracts; front portion becomes bladder and rear portion becomes part of rectum
XY phenotype
presence of Y chromosome and SRY gene has testes determining factor
- stimulates Leydig and Sertoli cells in gonad
- Leydig: testosterone to infl. Wolffian duct development into male structures
- Sertoli: AMH and regression of Mullerian ducts
embryology of the XY phenotype
- paramesonephric ducts inhibited by AMH
- stroma of indifferent gonad becomes testes under influence of TDF
- mesonephric duct develops under influence of testosterone from Leydig cells
- testes + vas deferens begin descent toward scrotum
- mesonepthric kidney degerates
gonadal + kidney development of XX genotype
cortex of indifferent gonad becomes ovary
- paramesonephric duct persists + develops into oviduct & uterus, mesonephric duct degenerates
- mesonepthric kidney degenerates
- bud from mesonepthric duct becomes ureter and metanephros (kidney)
- kidney + ureter ascend while gonads descend
gonadal + kidney development of XY genotype
- stroma of indifferent gonad becomes testes
- mesonephric ducts stimulated to develop and paramesonephric ducts are actively inhibited
- mesonepthric kidney degerates
- bud from mesonephric duct becomes ureter and kidney
- kidney + ureter ascend while gonads descend
persistent Mullerian duct syndrome
condition in which testicles can be held up in abdomen or pelvis, since paramesonephric ducts do not generate, usually b/c of shortage of AMH/MIS
inguinal descent of the testes
descent of testes through scrotum occurs through inguinal canal, which has a deep ring (opening to abdomen) and superficial ring (opening to scrotum); testes moves downward with gubernaculum
gubernaculum
aids the descent of testes through inguinal canal
genital tubercle
small projection on external surface; gives rise to external genitalia (glans clitoris or penis)
labioscrotal swelling
swelling can develop into labia in females or scrotum in males
transversalis fascia
abdominal layer continuous with internal spermatic fascia; pulled w/ testes during descent
hydrocoele
collection of serous fluid in the scrotal sac around the testis
orchidopexy
surgical fixation of an undescended testicle
cryptochidism
undescended testes
why is the descent of the testes required?
the sperm cannot survive the body’s high core temp, and there would be an increased risk of developing testicular cancer
why do male gonads end up outside the body?
sperm need to maintain temperature 2-3º below body temp. in order to develop, in doing so the testes will move up and down using the cremaster and dartos muscles
cremaster muscle
skeletal muscle that arises from the internal obliques; elevates testes
dartos muscle
smooth muscle; wrinkles scrotal skin; pulls scrotum close to body
pampiniform plexus
a network of testicular veins that drain the testes and absorb body heat from the testes and scrotum
inguinal hernia
a hernia in which part of the intestine protrudes into the inguinal canal through weak fascia
urogenital folds
develop into penile urethra in males or labia minora in females
female vestibule
area b/w labia minora which contains the opening to the urethra and the vaginal opening
urethral folds (males)
at 10 weeks under the influence of androgens will begin to meet and seal up
midline raphe
joins centrally to form the line down the center of scrotum
intersex
possessing biological sexual characteristics of both sexes
XX intersex
chromosomally female w/ external genitalia that appear male; typically resulting b/c of virilization of female fetus by male hormones
congenital adrenal hyperplasia (CAD)
disease of the adrenal in which the male hormones arise due to overactive adrenal glands in fetal development
XY intersex
chromosomally male w/ external genitalia appearing to be female or incompletely formed; generally result of inadequate supply or insensitivity to male hormones
androgen insensitivity syndrome (AIS)
condition in which receptors for androgens are not working causing XY intersex (can also be due to shortage of androgens)
AMH stands for and does what
anti mullerian hormone
- is a transforming growth factor important for development of male phenotype
TDF
essential for determining and generating XY phenotype
The y chromosome contains what that gives testis determining factor
SRY
What does TDF stimulate?
sertoli cells in gonad which make anti-mullerian hormone
Mullerian ducts in females?
progress
Mullerian ducts in males?
regress and need AMH
Leydig cells in gonad make
test
Mullerian duct will give rise to
fallopian tube and uterus
The cortex of the indifferent gonads in females becomes
ovary
The bud off of mesonephric duct initiates
development of metanephros which develop into true kidneys
in both males and females what does the mesonephric duct become
ureter
XY: The stroma of the indifferent gonads becomes
testes
Between the mesonephric duct and paramesonephric duct which are activated and which are inhibited
- mesonephric duct is stimulated to develop
- paramesonephric are inhibited
inferior part of mesonephric duct becomes
vas deferens
