Embryo

Question 1

Sonic Hedgehog - what does it do, mutation causes what

Answer 1

involved in AP patterning

mutation = holoprosencephaly

Question 2

function of Wnt-7

Answer 2

needed for proper organization along dorsal-ventral axis in embryo

Question 3

homeobox (hox) genes - fn, mutation?

Answer 3

involved in segmental organization (craniocaudal)

mutation - appendages in wrong location

Question 4

when does gastrulation occur?

Answer 4

week 3 (3 layers = 3 wks)

Question 5

when does neural tube close by?

Answer 5

wk 4

Question 6

when does fetal period begin?

Answer 6

wk 8

Question 7

when does fetus start to have male/female genitalia?

Answer 7

wk 10

Question 8

tumor originating from Rathke’s pouch

Answer 8

craniopharyngioma

Question 9

when is embyro/fetus most susceptible to teratogens?

Answer 9

wks 3-8

Question 10

teratogenic effect of alkylating agents

Answer 10

absence of digits

Question 11

teratogenic effect of DES

Answer 11

vaginal clear cell adenoCA

Question 12

teratogenic effect of lithium

Answer 12

Ebstein’s anomaly - atrialized RV

Question 13

teratogenic effect of thalidomide

Answer 13

limb defects (“flipper” limbs)

Question 14

MCC congenital malformation in US

Answer 14

fetal alcohol synd

Question 15

what part of placenta secretes HCG?

Answer 15

syncytiotrophoblast

Question 16

aortic arch derivs

Answer 16

1 - maxillary art
2 - stapedial and hyoid art
3 - common carotid / part of internal carotid
4 - L - aortic arch, R - subclavian
6 - prox pulm art and ductus arteriosus

Question 17

branchial parts in embryo - which parts correspond to which layer of tissue

Answer 17

clefts - ectoderm
arches - mesoderm
pouches - endoderm

CAP

Question 18

simple mnemonic for branchial arch derivatives

Answer 18

1 - chew
2 - smile
3 - swallow STYlishly (stylopharyngeus)
4 - simply swallow and speak

Question 19

branchial pouch derivs

Answer 19

1 - middle ear stuff
2 - palatine tonsils
3 - inf parathyroids and thymus
4 - sup parathyroids

Question 20

what is the precursor of the female and male genitalia?

Answer 20

female - paramesonephric (mullerian) duct

male - mesonephric (wolffian) duct

Question 21

remnants of gubernaculum in males/females

Answer 21

male - anchors testes w/ in scrotum

female - ovarian ligmanet and round ligament of uterus