ER 20+21 Flashcards
importance of the mesonephric duct?
urogenital sinus?
Mesonephric duct is important for development of the male reproductive system
female vagina is partially formed from the urogenital sinus
gonadal ridges?
appear during week 5 on the medial aspect of the mesonephros
male and female are indistinguishable before week 7
important of primordial cells?
migrate from the umbilical vesicle to the gonadal ridges to initiate development of gonads
how are genders differentiated when is it done?
SRY gene?
sex determination is done by week 12
female: ovaries develop by regression of medulla
male: testes develop from regression of the cortex and differentiation of medulla
testis determining factor encoded by SRY gene leads to male development (testis)
congenital inguinal hernia?
the connecting portion of the process vaginalis does not obliterate
leaves a patency where intestines may herniate through
hydrocele
the process vaginalis contains a small amount of fluid before it obliterates
the fluid is usually reabsorbed
if not.. hydrocele
identified by transillumination
cryptorchidism and ectopic testis
cyto:
testes do not descend
lead to infertility and high risk for germ cell cancer
ectopic:
testes are in an abnormal place
Role of testosterone and AMH?
mesonephric ducts?
testosterone: stimulates in mesonephric ducts to transition into male genital ducts (from the leydig cells)
AMH: development of the paramesonephric ducts into female genital ducts is inhibited by AMH from sertoli cells
mesonephric ducts give rise to epididymis, ductus deferens, seminal vesicles
how is the prostate developed?
Endodermal outgrowths from the prostatic urethra differentiate into glandular tissue
development of the uterus
endo and myometrium?
the cranial portion of the paramesonephric duct becomes the uterine tubes
the caudal portion fuses together- from the uterine canal to give rise to the uterus.
endo and myometrium is formed from the splanchnic mesenchyme
double uterus?
bicornuate uterus?
unicornuate?
Bicornuate uterus with rudimentary horn?
double:
no or minimal fusion of the paramesonephric ducts
bicornuate:
if incomplete fusion is only superior
unicornuate:
incomplete development of one of the mesonephric duct
Bicornuate with:
One paramesonephric duct is inhibited and
this duct does not fuse with the second duct
vaginal agenesis
failure of the sinovaginal bulbs to develop and form the vaginal plate
the absence of the vagina is usually accompanied by no uterus
the development of the uterus induces the formation of the sinovaginal bulbs
vaginal atresia
failure of the canalization of the vaginal plate
imperforate hymen
failure of the inferior end of the vaginal plate to perforate
canal of nuck
the process vaginalis remains patent
this is subject to both herniation and hydrocele
females
targeted screening and population screening
target: screening of populations known to be at risk
Ex: affected person in family or high risk ethnic groups
population:
screening all members of a population regardless of family history (breast exam)
purpose of prenatal screening?
usually used to detect 3 abnormalities:
trisomy 21 and 18 ]
neural tube defects
alpha fetal protein?
synthesized in yolk sac, fetal GI and fetal liver
detectable at 6 weeks
peak at 12-14 weeks
can be used as a screening marker
first trimester test? date ?
second trimester test? date?
first:
11-14 weeks + 1 day
look for pregnancy associated plasma protein A
human chorionic gonadotropin
second: 14 weeks + 2days to 20 weeks
triple test:
AFP, estriol, and HCG
Quad test:
inhibin A
Low serum AFP,
low estriol
low PAPP-A
high β-hCG and high Inhibin A
trisomy 21
Low serum AFP, estriol, PAPP-A and β-hCG
trisomy 18 (edward syndrome)
first trimester test often shows reduced PAPP-A and β-hCG
second trimester doesn’t help with this diagnosis
trisomy 13 (patau syndrom)
cell- free DNA (non-invasive prenatal screening)
used to detect aneuploidy (trisomy)
may be used to detect mutation
challenges:
young maternal age
twins
previous pregnancy
neural tube effects can be best diagnosed by?
best diagnosed at 18 weeks with ultrasound and increased AFP
Enlarged nuchal translucency 11-14 weeks
associated with trisomy
chorionic villus sample
10-14 weeks
involves the removal of fetal cells by aspiration from the inner surface of placenta
direct chromosomal analysis by FISH
amniocentesis
15-18 weeks
amniotic fluid is aspirated with the help of ultrasound
fetal cells are pelleted and used for chromosome analysis
supernatant can be used for AFP testing
Percutaneous umbilical blood sampling (PUBS)
usually done after 18 weeks
Performed when there is a delayed suspicion of a
chromosomal abnormality usually detected by
ultrasound in 2nd trimester
PKU screening
First to be screened by using quantitative mass spectrometry or tandem MS
elevated levels of Phe in the blood
treated by Phe restriction
sickle cell detection and treatment
hemoglobin electro DNA test (PCR-RFLP)
treatment:
prevention of sickling crisis by blood transfusions and use of hydroxyurea
detecting thalassemia?
mean corpuscular hemoglobin and hemoglobin electrophoresis
cystic fibrosis detection and management
sweat test
DNA test
IRT test
manage:
Antibiotics to combat respiratory infections, gene therapy, management of associated malabsorption
SCID detection and management
RT-qPCR can detect
manage: bone marrow transplant
