First Aid: Reproduction Flashcards
(90 cards)
A child is born with holoprosencephaly, what is the likely mutation in this child?
What if the child had appendages in wrong locations, what mutation would cause this?
Sonic hedgehog gene mutation can cause holoprosencephaly
Hox genes determine segmental organization of embryo in craniocaudal direction
Which gene is necessary for proper organization along a dorsal-ventral axis?
Which gene stimulates mitosis of underlying mesoderm, causing lengthening of limbs?
Wnt-7 gene
FGF gene
Which stage of early fetal development is extremely susceptible to teratogens? What happens during this period?
Weeks 3-8, Embryonic Period
Neural tube formed by neuroectoderm (closes by week 4). Organogenesis occurs
What is significant during weeks 1, 2, 3, and 4 of development?
1 = hCG secretion around time of blastocyst implantation
2 = 2 layers, Bi-laminar disc (epiblast, hypoblast)
3 = 3 layers, trilaminar disc, gastrulation, primitive streak, notochord, mesoderm and its organization, and neural plate begin to form
4 = 4 limbs, upper/lower limb buds form, HEARt begins to beat
A pregnant patient comes in for a follow-up and you notice fetal cardiac activity on transvaginal US, which was not available during US the previous week. What week of fetal development is the fetus in? During which week would you be able to identify male/female genitalia?
She is in week 6
At week 10 will see genitalia
Which embryo derivatives give rise to PNS and CNS?
Ectoderm
PNS = Neural Crest
CNS = Neuroectoderm
A baby presents with craniopharyngioma. What would you find in this mass, and what embryo derivative did it develop from?
Benign Rathke Pouch tumor with cholesterol crystals, and calcifications.
Surface Ectoderm
Name all of the possible Mesodermal defects:
VACTERL
Vertebral defects Anal atresia Cardiac defects Tracheo-Esophageal fistula Renal defects Limb defects (bone/muscle)
A mother who is in her first trimester of pregnancy is highly at risk for a DVT. What should you prescribe her, what should you avoid?
Give her HEPARIN (does not cross placenta)
Warfarin is teratogen
A baby has renal damage, absence of digits, CN VIII toxicity, and neural tube defects along with developmental delay and intrauterine growth retardation. What drugs must have been given to the mother?
ACE inhibitiors - renal
Alkylating agents - Absence of digits
Aminoglycosides - CN VIII
Carbamazepine - everything else
Folate antagonists, Valproate may also cause neural tube defects
A baby presents with microcephaly, dysmporphic craniofacial features, hypoplastic nails and distal phalanges, cardiac defects, IUGR and intellectual disability. What are these constellation of symptoms and what could be one cause of this?
Fetal hydantoin syndrome
Phenytoin
Which drug may cause an Ebstein anomaly (atrialized RV)?
Lithium
A baby presents with caudal regression syndrome (anal atresia to sirenomelia), congenital heart defects and neural tube defects. What could be the cause?
Maternal Diabetes
What may result in the fetus from Vit. A excess in the mother?
Extremely high risk for spontaneous abortions and birth defects (cleft palate, cardiac abnormalties).
What are fetuses at risk for if the mother gets an XRay?
Microcephaly and intellectual disability
What is the most common monozygotic twin and what embryonic tissues do they share? What is least common? What is in the middle and when did cleavage for this occur?
75% cleavage occurs at 4-8 days (between morula and blastocyst) - monochorionic, diamniotic
<1% cleavage at 8-12 days (between blastocyst and formed embryonic disc) - monochorion, monoamnion
25% cleavage occurs 0-4 days (between 2-cell stage and morula) - dichorionic, diamniotic, placenta may be fused or separate
Which fetal embryological structure secretes hCG and stimulates corpus luteum to secrete progesterone during first trimester?
Which structure is responsible for making fetal cells of placenta?
Synctiotrophoblast (outer layer of chorionic villi)
Cytotrophoblast makes cell
Where is the maternal placental component derived from?
Endometrium
What are the components of the umbilical cord and where are these parts derived from? What vessels do they connect? What are defects in this structures associated with?
2 umbilical arteries - return deox blood from fetal internal iliac arteries to placenta
1 umbilical vein - supplies oxy blood from placenta to fetus (drains into IVC via liver or ductus venosus)
These arteries and vein are derived from ALLANTOIS
Single umb. artery associated with congenital and chromosomal anomalies
A baby presents with urine discharge from umbilicus. What failed to occur in this child?
What if the child had a fluid-filled cavity lined with uroepithelium between the umbilicus and bladder? What is worrisome here?
Patent Urachus - failure of urachus to obliterate
Urachal Cyst - partial failure to obliterate –> risk for infection and adenocarcinoma
What connects the yolk sac to the midgut lumen and when is this structure destroyed?
What connects fetal bladder to the yolk sac?
Vitelline duct (obliteration at 7th week)
Urachus
A baby presents with melena, periumbilical pain and ulcers. They show signs of ectopic gastric mucosa and pancreatic tissue. How did this problem arise?
Meckel diverticulum - partial closure of Vitelline duct, with patent portion attached to ileum (true diverticulum)
A baby presents with meconium discharge from the umbilicus, what failed to occur in this child?
Failure of Vitelline duct to close leading to vitelline fistula
Describe the structure of the branchial apparatus:
CAP covers outside to inside branchial: Clefts = ectoderm Arches = mesoderm Pouches = endoderm