Head & NeckDevelopment Flashcards
What’s the other name for pharyngeal arches
brachial arches
why is viscerocranium unique
bones come from neural crest cells
the aortic arches perfuse and form what
pharyngeal arches
what pharyngeal arches are there
1, 2, 3, 4, 6
what nerve is from first pharyngeal arch
CN V2-3
trigeminal
what do CNV2-3 supply
muscles of mastication
what nerve comes from second pharynggeal arch
CN VII
What nerve comes from third pharyngeal arch
CN IX
What nerve comes from fourth and sixth pharyngeal arch
CN X
what muscles does VII supply
facial expression
are pharyngeal arches bilateral?
yes
at the end of 8th week what is done
organogenesis
at 4th week what is baby called
embryo
pharyngeal arches extend from what to what
stromoderm to respiratory diverticuluum
what goes into mesenchymal core?
neural crest cells
ectodermal placodes & neural crest cells
lateral plate mesoderm
paraxial mesoderm
what radiates into mesenchymal core
neural crest cells
what does neural crest cells form onec it goes into mesenchymal core
cartialge, bone, skeletal muscles, CT, nerves
all the tendons of muscle in face are directly influenced by what
neural crest cells
what does lateral plate mesoderm form
vasculature
what specific blood vessels enter mesenchymal core
pharyngeal arteries
paraxial mesoderm helps form what
craniofacial skeletal muscle & bone
ectodermal placodes and neural crest cells formw hat
neurons of CN V, VII, IX, X cranial sensory ganglia
what happens after things enter mesenchymal core
that is an intermeidate step - they go there and then go to target organs
visceral cranium is formed from what
neural crest cells
what is everything else in neurocranium formed from
paraxial mesoderm & neural crest cells
what is difference b/w somatomeres and somites functionally
nothing
what muscle groups skip the pharyngeal arches completely
tongue & extraocular eye muscles
which arch helps form viscerocranium
Arch 1
what is arch 1 called
mandibular arch
maxillary prominence helps form what
muscles of mastication
maxillary prominence’s mesenchyme helps form what
maxilla, zygomatic, temporal bones
99% of meckel’s cartilage does what
goes away
why do we have meckel’s cartialge if we get rid of most of it
some things fomr from it like incus, malleus, sphenomandibular ligament
mandible is formed from what
membranous ossification of mesenchymal tissue
meckel’s cartilage does not form what
mandible
what forms mandible
the mesenchymal tissue surrounding meckels’ cartilage
what 3 things does meckel’s crtialge make
incus, malleus, sphenomandibular ligament
what is arch 2 called
hyoid arch
what does reichert’s cartilage form
styloid process, stapes, most of hyoid, stylohyoid ligament
what is the second part to pharyngeal arches
pharyngeal pouches & clefts/grooves
inner lining of pharyngeal arch 2 is what
a pouch
outside of pharyngeal arch 2 is what
cleft
what happens to most of cleft and pouch
they go away
what does 1st pouch form
epithelial lining of middle & outer ear, tympanic membrane, pharygotympanic tube
tympanic membrane is the only structure in entire body derived from what
all 3 germ layers: ectoderm, endoderm, mesdoderm
external ear is lined with what
skin (ectoderm)
middle ear is lined with what
endoderm
in b/w external and middle ear is what
mesoderm
what does 2nd pouch help form
epithelial lining of palantine tonsil
1st arch is lined and filled with what
ectoderm
parathyrodi and thyms will descend to where
final position
when will parathyroid and thymus make its descent
to final position by week 7
what does 3rd pouch form
epithelial components of thymus gland and inferior parathyroid gland
what does 4th pouch form
superior parathyroid gland & parafolliclular cells of thyroid
what does 5th & 6th pouch form
nothing
what separates stromoderm from pharyngeal foregut
oropharyngeal membrane aka buchopharyngeal membrane
the mandibular prominenc must do what
fuse together
why does mandibular prominence need to fuse together
everything else uses it as scaffolding - if it doesn’t form everything else collapses
after mandibular prominence is fused together, what happesn
maxillary prominneces fuse together
how do maxillary prominences fuse
upward and medial
medial nasal primineces are formed by what
maxillary prominnces fused together
lateral nasa prominenes fuse with what
maxillary prominences
when lateral and maxillary prominences fuse they force what duct inward
nasolacrimal duct
what is nasolacrimal duct origin
ectoderm (forced down by lateral and maxillary prominence)
nose is formed from what
frontal nasal prominences (bridge of nose
what forms crest and tip of nose
medial nasal prominsne
what forms ala of nose
lateral nasal prominence
what form upper li and cheeks
maxillary prominence
what form chin, lower lip, lower cheek region
mandibular prominence
primary palate fuses with what
secondary palate
primary, secondary, and nasal septum are all occuring
at the same time
if medial nasal primence does not fuse with maxillary nasa primences what is clincal correlation
cleft lip
if secondary palate does not fuse with other or with primary palate what is it
cleft palate
More severe deformity where non-fusion extends to maxilla (between 1o and 2o palate) and can be unilateral or bilateral is what
cleft lip & palate
in bilateral cleft lip and palate what is only thing holding it in place
nasal septum
2 medial nasal prominences fail to fuse and often accompanied by mental retardation is what clinical correlation?
medial clefted upper lip
Nasolacrimal duct remains exposed due to the lateral nasal process failing to fuse with the maxillary process and can occur along with a cleft lip is what clincal correlation
oblique facial cleft
what is mesoderm beinf formed from that makes the nose
neural crest cells
describe what nasal pits/sac ectoderm does as it grows
grows inward through mesoderm of frontonasal priminece
tongue is lined with what
skin
why is tongue lined with skin
pharyngeal arch 1
what is difference in pharyngeal arch 1
lined with ectoderm
tuberculum impar helps form what
body of tongue
hypobranchial eminence is from which pharyngeal arhches
2-4
what is unique about occipital somites
they do not go through pharyngeal arches
what kind of muscle is occiptal somites
skeletal
posterior 1/3 of tongue is initially formed from what
arch 2-4
on posterior 1/3 of tongue what is is made out of initially
arches 2-4
is there any pharyngeal arch 2 derivitive in pofinal formation of otongue & why?
no, pharyngeal arch 3 overgorws all of arch 2 and most of 4
does all paraxial mesoderm go directly to target and do not enter pharyngeal arches?
no
does arotic arches enter pharyngeal arhces first?
no
epithelial lining of salivary glands si formed from what
pharyngeal arch’s pouches & grooves + other stuff
correct formation of face requires what to be formed first
mandibular prominence
is mouth part of GI tract embryolgically
no
why is mouth not part of GI tract embryologically
does not have endoderm inside and VLPM outside - mouth has skeletal muscles (from pharyngeal arches)
why is nasal lacrimal duct ectoderm
it’s pushed back, formed initially from skin and is forced inward by fusion of lateral nasal prominence and maxillary
why is nasal lacrimal duct ectoderm
it’s pushed back, formed initially from skin and is forced inward by fusion of lateral nasal prominence and maxillary
what is unique thing about pharyngeal arches compared to the rest of embryo
all the pieces coming form all different places mix together and connect and then go to their target organs
what is unique thing about pharyngeal arches compared to the rest of embryo
all the pieces coming form all different places mix together at the same time and connect and then go to their target organs (vs. in limbs where things come in in sequential order)
what is unique thing about pharyngeal arches compared to the rest of embryo
all the pieces coming form all different places mix together at the same time and connect and then go to their target organs (vs. in limbs where things come in in sequential order)
the pouches and cleft form epithelial lining of what
glands (all of them)
what skeletal structures does first arch form
malleus incus maxilla mandible zygomatic bone part of temporal
what muscles does first arch form
muscles of mastication mylohyoid anterior belly of digastric tensor tympani tensor veli palatini
what ligaments does first arch form
anterior ligament of malleus
sphenomandibular ligament
what muscles does second arch form
muscles of facial expression
stapedius
stylohyoid
posterior belly of digastric
what skeletal structures does second arch form
stapes
styloid process
lesser cornu of hyoid
upper part of body of hyoid bone
what ligament does the second arch form
stylohyoid ligament
what muscle does the third arch form
stylopharyngeus
what skeletal structure does the third arch form
greater cornu of hyoid
lower part of body of hyoid bone
what muscles do 4th and 6th arch form
cricothyroid levator veli palatini contrictors of pharynx intrinsic muscles of larynx striated muscles of esophagus
what skeletal structures do 4th and 6th arch form
thyroid cartilage cricoid cartilage arytenoid cartilage corniculate cartilage cuneiform cartilage
