Development of the Head and Face Flashcards
What is the name of the expanded region at the cranial end of the primitive groove?
What does it do?
primitive node
directs the formation and disappearnce of the primitive groove
What happens at the prechordal plate?
What feature of the embryo does this signify?
the epiblast and hypoblast cells have stuck together so that the mesoderm cannot get between
this signifies the cranial portion of the embryo & important signaler for differentiation of the head
What is the chordamesoderm?
group of mesoderm that rolls through the primitive node and migrade cranially (mesoderm that will form the notochord)
little tip of chordamesoderm at the tip of the cranial direction that does not differentiate into notochord
nondifferentiated chordemesoderm and prechordal plate set signaling for what structure?
How does it do this?
neural tube (head)
- signaling markers to ectoderm, cauing ectoderm immediately superficial to differentiate (neural ectoderm)
- neural ectoderm will break free and form neural tube
- neural tube combines with chordemesoderm and prechordal plate to form the head
What is the name of the embryonic forehead?
What is makes up the early mouth?
frontonasal prominence
oropharyngeal membrane
Identify the aspects of the early face
What fuses to form the lower jaw?
What fuses to form the upper jaw?
lower jaw: mandibular processes
upper jaw: maxillary and nasomedial processes
Identify the features of the developing face
Where does most of the connective tissue of the face develop from?
most of the connective tissue of the face develops rom neural crest cells and migrates to the area
What portion of the face is nerual crest derived?
What portion of the face is mesoderm derived?
nerual crest: ventral
mesoderm: dorsal
What three major structures are formed from the first pharyngeal arch?
maxilla, mandible, inner ear ossicles
Which muscels are formed from the first pharyngeal arch?
Which muscles are formed from the second pharyngeal arch?
1st: muscles mastication
2nd: muscles of facial expression
Which cranial nerve is associated with the first pharyngeal arch?
Which cranial nerve is associated with the second pharyngeal arch?
1st: trigeminal
2nd: facial
What is the new name once the two medial nasal prominences merge?
What other fusion is necessry for normal development?
the primary palate
fusion of the medial nasal processes and the advancing maxillary processes
When the primary process grows dorsally, what does its name change to?
What is the name of the shelf of bone growing out of the medial side of the maxillary?
Together these structures form what?
median palatal process
lateral palatal process
the secondary palate
Why does the tongue have such a weird innervation pattern?
It is formed from the first 3 arches
it gets trigeminal from the first (lingual)
facial from the second (chorda tympani)
and glossopharyngeal from the 3rd
What is formed from the pharyngeal pouches and clefts?
- First cleft and pouch
- auditory system
- external auditory meatus
- tympanic membrane and tympanim
- 2nd pouch
- palatine tonsils
- Rest of pouches
- midline glandular derivatives
- thyroid
- thymus
- parathyroid
- midline glandular derivatives
What are the two examples of First Arch problems?
- Treacher Collins Syndrome
- autosomal dominant
- abnormal mandible and zygomatic development
- disruption orbit of the eye, ear, and tongue
- Pierre Robin Sequence (Syndrome)
- may be genetic
- micrognathia
- displaced tongue
- cleft palate
- obstructed airway
What is the outcome if the palates do not fuse medially?
cleft palate
check out all these patterns of cleft palate formation
What happens when pharyngeal clefts persist?
can see sometimes when infants are succling
instead of disapearing, they can fill with fluid or tissue
