3/16 Repro Flashcards
Bicornuate uterus
-due to what?
incomplete fusion of paramesonephric ducts
Germ cell tumor & inc. T4 & T3.
-whats the connection?
Germ cell tumor releases bHCG which has same alpha-subunit as TSH (and LH & FSH).
-This acts like TSH and causes thyroid to produce more thyroxine!
*bHCG shares significant sequence homology in the beta-subunit w/TSH as well.
Superficial inguinal nodes
-drain what region?
- all cutaneous lymph from umbilicus to the feet including external genitalia & anus (until pectinate line).
- excludes posterior calf which drains to popliteal l.nodes.
main mode of action of OCPs?
suppress synth of FSH and LH.
- leads to inhibition of ovulation (no LH spike).
- also cause thickening of cervical mucus, but this is not the main mode of action.
Which HPV causes warts?
6 & 11
Which HPV can cause cervical carcinoma?
16, 18, 31, 33
citrate
-effect w/renal stones?
-high citrate is good, binds calcium and prevents it from precipitating.
direct inguinal hernia
-cause?
weakness of transversalis fascia.
Sonic hedgehog gene
- patterning along which axis?
- involved in development of what?
- mutation can lead to what?
- anterior-posterior axis.
- Involved in CNS development
- mutation can cause holoprosencephaly.
Wnt-7 gene
-Necessary for proper organization along which axis?
dorsal-ventral axis.
FGF gene
-function?
-Stimulates mitosis of underlying mesoderm, providing for lengthening of limbs.
Homeobox (Hox) genes
- involved in organization of embryo in which direction?
- mutations lead to what?
- craniocaudal direction
- Hox mutations appendages in wrong locations.
Bilaminar disc
-which week?
2 weeks = 2 layers
When is fetus most susceptible to teratogens?
Weeks 3-8, the “embryonic period”.
-this is when organogenesis occurs.
Upper & lower limb buds begin to form
-which week?
4 weeks = 4 limbs
Heart begins to beat
-which week?
week 4
-4 chambers in your heart
Fetal cardiac activity visible by transvaginal ultrasound.
-which week?
week 6
Genitalia have male/female characteristics.
-which week?
week 10
gastrulation
- what is it?
- what starts it off?
- Process that forms the trilaminar embryonic disc.
- Establishes the ectoderm, mesoderm, and endoderm germ layers.
-Starts with the epiblast invaginating to form the primitive streak.
First 2 layers of the inner cell mass?
-which contributes to the embryo?
epiblast & hypoblast
-epiblast becomes the embryo
What is the epiblasts new cavity?
amniotic cavity
-it will eventually surround the entire embryo.
which sect of the mesoderm forms the parietal body cavity?
somatic/parietal lateral plate mesoderm
*Amniotic cavity follows it around & now surround the entire embryo. It disconnects from the somatic lateral plate mesoderm.
which sect of the mesoderm forms the gut tube/CT/smooth muscle of gut tube?
visceral/splanchnic lateral plate mesoderm
Neural crest origin
- which marker?
- name some structures
S-100 (+)
- melanoma
- schwannoma
- langerhan cell histiocytosis
Notochord
-adult derivative?
Nucleus pulposus of intervertebral disc.
Deformation vs malformation
Deformation = extrinsic disruption; occurs after the embryonic period.
Malformation = intrinsic disruption; occurs during the embryonic period (weeks 3–8).
Absence of digits
-which teratogen?
alkylating agent
fingernail hypoplasia
-which teratogen?
Carbamazepine, phenytoin.
Aplasia cutis congenita
-which teratogen?
Methimazole
Fetal hydantoin syndrome
- which teratogen?
- what is it?
-phenytoin
-microcephaly, dysmorphic craniofacial features, hypoplastic nails and distal phalanges, cardiac defects,
IUGR, intellectual disability
Caudal regression syndrome (anal atresia to
sirenomelia)
-which teratogen?
glucose
-Maternal diabetes
Smooth philtrum, thin upper lip
-which congenital problem?
fetal alcohol syndrome
hypertelorism
Abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the orbits (eyes)–orbital hypertelorism.
What is a chorion?
placenta
Dizygotic twins
- how many chorions?
- how many amniotic sacs?
- 2 separate chorions
- 2 separate amniotic sacs
Monozygotic twins
-When do you get 2 chorions (placentas)?
If they split before day 4.
-after day 4, you always get just 1 chorion (placenta).
Monozygotic twins
-when does the fertilized egg split into 2 zygotes?
75% of the time, day 4-8.
25% before day 4.
<1% after day 8.
Monozygotic twins
-at what point will they share an amniotic cavity?
If they split after 8 days, which is <1%.
-so 99% of the time, you will have 2 amniotic cavities.
Conjoined twins
- when do they split?
- how many chorions?
- how many amniotic sacs?
> 13 days.
-monoamniotic, monochorionic.
Most common twinning:
- when is the split?
- how many chorions?
- how many amniotic sacs?
75% of the time, day 4-8
- Monochorionic
- Diamniotic
Inner layer of chorionic villi.
Cytotrophoblast
-Cytotrophoblast cells = mitotically active & serve as the stem cells for formation of the syncytiotrophoblast. The syncytiotrophoblast is mitotically inactive.
Outer layer of chorionic villi
Syncytiotrophoblast
Syncytiotrophoblast or Cytotrophoblast
-which makes bHCG?
Syncytiotrophoblast
Umbilical vessels
- 2 of which?
- mnemonic?
2 umbilical arteries
*arteries = longer word = there are more of them.
Umbilical arts
-stem from which fetal arteries?
internal iliac arts.
Umbilical arteries and veins are derived from:
Allantois
urachus
- derivative of what?
- function in utero?
- allantois becomes the urachus.
- Duct connecting fetal bladder to yolk sac and allows bladder to drain waste into the yolk sac.
Urachal cyst
-can predispose to what cancer?
-adenocarcinoma at dome of the bladder.
obliterated urachus becomes what?
-median umbilical ligament.