embyro triage exam 4 Flashcards
The basal plate becomes whih horn of the spinal cord?
the ventral horn and the lateral horn of the spinal cord (somatic motor)
the alar plate becomes which horn of the spinal cord?
becoems the dorsal horn for sensory neuroblasts
dorsal root ganglia are dervid from what?
neural crest cells
what forms the dura?
mesoderm
what forms the pia and arachnoid mater?
neural crest cells
what embryonic structure participates the most in the formation of the PNS?
neural crest cells
what innervates the first pharyngeal arch?
Trigeminal : the third mandibulr branch of trigem (V3) has that little motor branch and this innervates the muscles of mastication.
What pharyngeal arch do the muscles of mastication come from?
the first!
what innervates the second pharyngeal arch?
the facial nerve
what innervates the third pharyngeal arch?
glossopharyngeal
the stylopharyngues muscle is derived from which arch?
the third
what innervates the 4th pharyngeal arch?
vagus nerve (X)
what innervates the 6th pharyngeal arch?
the recurrent branch of vagus (X)
pharyngeal pouches are made of what
endoderm
pharyngeal grooves/clefts are made of
ectoderm
pharyngeal arches are made of
ectoderm, endoderm and mesoderm
what does the first pharyngeal pouch make?
the inner ear
what does the 2, 3 and 4th groove form?
nothing! they disappear
what does the first pouch form?
inner and middle ear, eustachian tube
what does the second pouch form?
the tonsilar bed , palatine tonsils
what does the 3rd pouch form?
the thmus and inferior parathyoid
what does the 4th pouch form?
superior parathyoid gland
the parathyroid glands are derived from which pouches?
the 3rd and 4th
The only phagyngeal membrane that gives rise to adult derivatives is:
first pharyngeal membrane
A 2 day old infant male has a noticeable gap in his upper lip. The diagnosis is a cleft lip. Failure of fusion of which structures is the most likely cause of this anomaly?
Maxillary processes and intermaxillary segment`
how is the primary palate formed?
it is formed by the merging of the medial nasal prominences
how is the secondary palate formed?
by the fusion of the 2 palatine shelves/ plates
the majority of the palate develops from the
lateral palatine process
As soon as he stops crying he becomes breathless and cyanotic. With tactile stimulation he cries again and cyanosis resolves, but returns every time he is quiet. What is your diagnosis?
The cause is the persistence of an intact oronasal membrane and lack of communication between nasal cavities and nasopharynx. Newborns are obligate nose breathers. At birth, as long as they cry, they can breath orally. When they stop crying they become breathless and cyanotic.
The inner ear derives from:
ectoderm
malleus and incus arise from
the 1st pharyngeal arch
stapes arises from
2nd pharyngeal arch
pharyngeal grooves are made by what?
ectoderm
pharyngeal puches are made by what?
endoderm!
what germ layer creates the nasal placodes
ectoderm
in an oblique facial cleft whats happened?
maxillary prominence and lateral nasal process don’t fuse
a median cleft lip occurs when
the medial nasal processes fail to fuse
when the medial nasal processes fuse what do they form?
the intermaxillary segment
What happens if the intermaxillary segment and maxillary prominences do not fuse
cleft lip
A 2 day old infant male has a noticeable gap in his upper lip. The diagnosis is a cleft lip. Failure of fusion of which structures is the most likely cause of this anomaly?
. Maxillary processes and intermaxillary segment
primary (anterior) palate is formed how
formed by merging of the medial nasal prominences
secondary (posterior) palate is forme dhow
fusion of the palatine (palatal) shelves (plates, processes) from the maxillary processes
cleft palates are due to
result of the failure of neural crest cells to migrate/proliferate
Anterior clefts
lateral palatine processes fail to fuse with primary palate.
Posterior clefts:
lateral palatine processes fail to fuse with each other and with the nasal septum
complte cleft palate is due to
lateral palatine processes fail to fuse with each other, nasal septum and primary palate
