Pouches and clefts Flashcards
what are pouches
invaginations of endoderm in the lateral walls of the pharynx
1st pouch
tympanic cavity
2nd pouch
palatine tonsil
3rd pouch
parathyroid and thymus
4th pouch
parathyroid gland and parafollicular cells of thyroid
what is an ectopic thymus
thymus remains in the neck
1st cleft
external auditory meatus and tympanic membrane
which arch proliferates to overgrow the 3rd and 4th arches
2nd
which clefts lose contact with the exterior forming the cervical sinus
2nd 3rd and 4th
what is the most common congenital disease of the neck
branchial cleft anomolies (cysts- adults, fistulas/sinuses- children)
whre are branchial cleft anomolies found
anterior to sternocleidomastoid
presume cancerous until proven otherwise
what is the function of hox genes
rostrocaudal patterning
what pouches dont form properly in digeorge
3rd and 4th pouches
what gene is involved in width of facial features
Sonic hedgehog
what problems can arise from SHH malfuncion
cyclopia
holoprosencephalon
diprosopus
what is craniosynostosis
fgf gene signalling activates bone calcification and reduces cell proliferation in the mesenchyme causing premature fusion
this causes brachycephaly and a misformed head
what is Irf6
craniofacial defects
epidermis defects
what genes are involved in cleft lip
PHF8 siderius x linked mental retardation
irf6 in van der woude and non syndromic
what structure flips above the tongue
palatine shelf
what can cause thyroid dysgenesis
pax8 and titf1
describe the somatopy in the NTS
ant tongue post tongue epiglottis carotid sinus and body aortic arch (commisural nuceus for cardiovascular reflexes)
what are the tongu swellings
lateral lingual
copula
epiglottal
