anatomy/embryology/genetics Flashcards
Skin, nerves, brain
ectoderm
lungs, liver, pancreas, GI
Endoderm
many different parts
*skeletal muscle, blood vessels, conncective tissue
mesoderm
kidneys, ovaries, testes
intermediate layer
Where does the labia, clitoris and lower vagina arise from?
urogenital sinus
what weeks are the Labia, clitoris and lower vagina undifferentiated?
week 1-7
what weeks are the Labia, clitoris and lower vagina differentiated?
week 12 `
what causes differentiation of the labia, clitoris and lower vagina?
Testosterone
* if it is absent: female genitalia will develop
* if present: male genitalia will develop
What happens if you have a genetically female fetus (XX) and there is congenital adrenal hyperplasia?
excess androgen is produced, so the XX chromosome is still being exposed to testosterone- the genitalia will develop more towards male anatomy
when do ovaries develop? how?
3rd week of gestation.
migration of germ cells- no migration, no ovaries
At what weeks does a female fetus have the maximum number of oocytes?
16-20 weeks (produced from germ cell proliferation)
Congenital absence of ovaries (very rare)
Ovarian dysgenesis
Absence of ovaries are usually due to chromosomal abnormalities. What is an example of that?
Turner Syndrome (45XO) missing X
In turner syndrome, what are the ovaries referred to?
Streak ovaries or smear ovaries
Turner syndrome patients often present due to?
delayed menarche, puberty, webbed neck, widely space nipples
Tubes, uterus, cervix and upper vagina arise from?
Genital ducts
* wolffian- produce male genitalia
* Mullerian ducts- produce female genitalia
in females what duct disappears? what duct persists? what does that duct migrate into?
Wolffian ducts disappear, mullerian ducts persist
* caudal ends fuse to form uterus, cervix and upper vagina
* as ducts move toward fusion- they carry peritoneum, which become broad ligament
mullerian abnormality that is a complete failure to fuse
Uterus didelphys (end of with a uterus, cervix and vagina on two sides) *most rare
mullerian abnormality where ducts fuse but no degeneration of the fused tissue
Bicornuate uterus
mullerian abnormality where there is a failure to fuse and degenerate
unicornate uterus (w/or w/o horn) (one side migrated and developed normally and the other did not)
wolffian remnants
Gartner cysts
No mullerian ducts; absence of uterus, tubes and cervis
Mullerian agenesis (external genitalia looks normal but you won’t find normal anatomy)
where is the upper vagina developed from?
mullerian ducts
where is the lower vagina from?
urogenital sinus
area that contains the uterus, vagina, bladder, fallopian tubes, ovaries and distal rectum/anus
Lesser pelvis (true)
area that holds the weight of the abdominal organs and pregnant uterus
Greater pelvis
why is important to asses the size of true pelvis?
obstetrical conjugate is important to know if the portion of the pelvis will be able to pass a child vaginally
which portion of the cervix communicates with the vagina?
external os
which portion of the cervix communicates with the uterus?
internal os
one of the main supports for the fallopian tubes; tubes ovaries, round and uterine ligaments, nerves, uterine artery, lymphatics
Broad ligament
Ligament that is a problem child during pregnancy; can cause stress and pain with rapidly growing fetus
round ligament
continuous with the fallopian tube; means horns
Cornu
uterine wall: surrounding the whole organ
perimetrium
what are the three regions of the fallopian tubes?
isthmus
ampulla
infundibulum
what part of the fallopian tube is fixed within the broad ligament?
isthmus
what is the #1 site for ectopics
ampulla
has fimbriae, ciliated columnar cells, no direct connection with ovaries
infundibulum
Where does mitosis occurs?
mitosis occurs in somatic celss
what does mitosis produce?
produces 2 daughter cells of same genetic materia
where does meiosis occur?
germ cells
what does meiosis produce?
2 divisions resulting in 4 haploid, genetically distinct cells
most chromosomal anomalies are a result of
nondisjunction in meiosis 1 (before birth)
what is nondisjunction?
division did not occur correctly
rarely skips generations; equal sex distribution; an unaffected individual will not transmit gene to his or her progeny
autosomal dominant
appears to skip generations; both genders affected; neither parent is usually affected (asymptomatic carrier)
Autosomal recessive
what phase of meiosis allows the most diversity? often error prone
anaphase 1
affected gene located on X chromosome; both recessive and dominant disorders exist; recessive d/o affects males>females; phenotype of disease is based on one allele
X- linked inheritance
affect females 2x> males; males more severely affected
X-linked dominant
risk factors for genetic disorders?
-advanced maternal age >35
-previous pregnancy with chromosomal abnormality
-hx of pregnancy loss
-advanced paternal age >50
