Lec 31: Craniofacial Development Flashcards
What is the prominence that covers the cranial forebrain?
Frontonasal prominence
What branchial arch contains the maxillary prominence and mandibular prominence?
Branchial arch 1 (also the largest)
What is the embryonic structure that gives rise to the mouth and anterior oral cavity?
Stomodeum
What embryonic structures give rise to the lens, inner ear, and nasal epithelium?
The ectodermal placodes
What are the 5 prominences that aid in formation of the face and jaws?
2 Mandibular
1 frontonasal prominence
2 maxillary
What does the mandibular prominences contribute to?
Lower jaw, lower lip, floor of mouth, and part of tongue
What does the frontonasal prominence contribute to?
- forehead and nasal reigon
- two medial and two lateral nasal prominences
What are the skeletal derivatives of branchial arch 1? Muscle derivatives? Motor innervation?
Skeletal: Maxilla, mandible, incus, malleus, zygomatic
Muscle: muscles of masication
Motor innervation: trigeminal (V)
What are the skeletal derivatives of branchial arch 2? Muscle derivatives? Motor innervation?
Skeletal: Stapes, upper hyoid
Muscle: facial muscles, stapedius, posterior belly of digastric, stylohyoid
Motor innervation: facial (VII)
What are the skeletal derivatives of branchial arch 3? Muscle derivatives? Motor innervation?
Skeletal: lower hyoid
Muscle: stylopharyngeus
Motor: glossopharyngeal (XI)
What are the skeletal derivatives of branchial arches 4-6? Muscle derivatives? Motor innervation?
Skeletal: laryngeal cartilages
Muscle: soft palate muscles, pharyngeal and laryngeal muscles
Motor vagus (X)
What are the two tissue types contained within each branchial arch?
Neural crest cells (skeletal derivatives)
Mesoderm (muscle derivatives)
What is the fate of pharyngeal pouch 1?
tympanic cavity and auditory tube, tympanic membrane (in conjunction with 1st arch)
What is the fate of pharyngeal pouch 2?
palatine tonsils
What is the fate of pharyngeal pouch 3?
thymus and inferior parathyroids
What is the fate of pharyngeal pouch 4?
Superior parathyroids (migrate ventrally)
What is the fate of pharyngeal pouch 5 (postbranchial body)?
associated with crest-derived C-cells of thyroid
What is the fate of the ventral midline diverticulum?
thymus (migrates ventrally)
What is the source of Shh, what is its role, and what disease do disruptions in it cause?
Source is notochord and prechordal mesoderm, as well as facial ectoderm and foregut endoderm
Role is in forebrain induction and crest development
Related to holoprosencephaly and possible Down Syndrome
What is the source of RA, what is its role, and what disease do disruptions in it cause?
Source is paraaxial and lateral mesoderm
Role is in Hox programming and crest development
Related to Fetal Retinoid syndrome
What is the role of TCOF1, and what disease is is related to if disrupted?
Role is in 1st and 2nd branchial arch development
Related to Treacher Collins
What is the source of Tbx1, its role, and its related disorder?
Source is pharyngeal endoderm and mesoderm
Role is in crest and 3-4th pouch development
Related to 22q11 deletions (DiGeorge syndrome)
How does a unilateral cleft upper lip result?
Failure to fuse of medial nasal and maxillary prominences
How does an anterior cleft palate result?
Failure to fuse of medial palatine process with lateral palatine shelf
How does a posterior cleft palate result?
Failure to fuse of two lateral palatine shelves
