Flashcards in Embryo/Repro Deck (227)
What is seen with a mutation in the Sonic Hedgehog gene?
What is the function of the Wnt-7 gene?
Ventral-dorsal axis organization
What is the function of the FGF gene?
Found at apical ectodermal ridge (tip of limb). Stimulates mitosis of underlying mesoderm --> lengthening of limbs
What is the seen with mutation of the Homeobox genes?
Hox genes orient the embryo in the cranial-caudal direction. Mutations cause limbs in the wrong places.
When is a fetus most susceptible to teratogens?
This is the embryonic period & is when most organs are formed.
When does gastrulation occur?
3 layers = Week 3 (trilaminar)
When during embryogenesis are the limbs formed?
4 limbs = Week 4
When can the sex of a baby be determined by US?
When does the neural tube form during embryogenesis?
What structures are formed from the neural crest?
Parafollicular thyroid cells
Pia & arachnoid
Bones of the skull
What are the mesodermal defects?
What structures are formed from the endoderm?
Gut tube epithelium
Thyroid follicular cells
What is the difference between agenesis & aplasia?
Agenesis = absent primordial tissue
Aplasia = Primordial tissue was present but organ is absent
What is the difference between Deformation & Malformation?
Malformation = intrinsic & occurred during embryogenesis
Deformation = Extrinsic & occurred after embryogenesis
What is the embryologic effect of ACE inhibitors?
What is the embryologic effect of alkylating agents?
Absence of digits & other anomalies
What is the embryologic effect of aminoglycosides?
Just like how they are ototoxic in adults
What is the embryologic effect of Lithium?
Ebstein's = Atrialized RV = most of the right heart is atrium
What is the embryologic effect of phenytoin?
Fetal hydantoin syndrome:
Dysmorphic craniofacial features
Hypoplastic distal phalanges & nails
Intrauterine growth restriction
What is the embryologic effect of Tetracyclines?
What is the embryologic effect of thalidomide?
"Flipper" limb defects
What is the embryologic effect of Valproic acid?
Inhibits maternal folate absorption --> neural tube defects
What is the embryologic effect of warfarin?
Use heparin during pregnancy
What is seen with cocaine use during pregnancy?
Abnormal fetal development
What is seen with smoking during pregnancy?
What can be seen in infants born to diabetic mothers?
Caudal regression syndrome (aka sacral agenesis; ranges from anal atresia to full blown sirenomelia)
Congenital heart defects
Neural tube defects
When must separation occur to cause the various types of monozygotic twins?
4-8 days (morula) --> Monochorionic diamniotic
8-12 days (blastocyst) --> Mono-mono
> 13 days --> mono-mono & conjoined
What are the chorionic villi composed of?
Which cell type secretes hCG?
Cytotrophoblasts (inner layer)
Sincytiotrophoblasts (outer layer) - secrete hCG
What is the urachus?
What pathology is seen with it?
Allantois --> Urachus --> Median umbilical fold
Urachus is a duct between the bladder & yolk sack
1) Patent urachus --> Urine discharge from umbilicus
2) Vesiurachal diverticulum --> outpouching of bladder
3) Adenocarcinoma of the bladder