Stephens Embryo lecture Flashcards
CN of Arch 1
trigeminal
Skeletal of Arch 1
malleus, incus, maxilla, mandible, meckels
Muscle of Arch 1
muscles of mastication
CN of Arch 2
Facial nerve
Skeletal of Arch 2
reichert’s cartilage, stapes, upper hyoid bone, lesser cornu
Muscle of Arch 2
facial expression
CN of Arch 3
Glossopharyngeal
Skeletal of Arch 3
greater cornu, lower hyoid
Muscle of Arch 3
stylopharyngeus
CN of Arch 4
Vagus
Skeletal of Arch 4
laryngeal and thyroid cartilage
Muscle of Arch 4
pharyngeal and laryngeal mm.
Pharyngeal pouch 1
eustation tube, tympanic membrane, and external acoustic meatus
Pharyngeal pouch 2
tonsils, root of tongue
Pharyngeal pouch 3
inferior parathyroid, thyroid
Pharyngeal pouch 4
superior thyroid
Cranioschisis
failure of occipital and parietal bones to form or close
Microcephaly
small cranium due to early fusion of cranial sutures
Macrocephaly
enlarged cranium secondary to hydrocephaly from early fusion of superior cranial sutures
Apert Syndrome
premature fusion of coronal sutures
“tower skull”
associated with fetal alcohol syndrome
Cleft chin
mandibular prominences partially or completely fail to fuse
Anterior cleft deformity
failure of medial nasal and maxillary swelling to fuse
Posterior cleft deformity
failure of palatine shelves to fuse
Cleft lip
anterior deformity, more common in males
Cleft palate
posterior deformity, more common in females
Oblique facial cleft
failure of maxillary swelling to fuse with lateral nasal swelling (palatine shelves)
What is exposed with an oblique facial cleft
nasolacrimal duct
Median cleft lip and bifid nose
failure of medial nasal prominences to fuse
Macrostomia and microstomia
dysfunction of maxillary and mandibular swelling
Agathnia
dysgenesis of mandibular swelling
Neurocranium
first 10 weeks
cradles the skull
Viscerocranium- cartilaginous
forms brachial arches
Viscerocranium- membranous
forms maxillary and mandibular processes of arch #1
Stomodeum origin
ectoderm
Stomodeum function
demarkation of anterior 2/3 of oral cavity vs posterior 1/3 of oral cavity
Facial Swellings
frontal prominence, maxillary prominence, and mandibular prominence
Frontal prominence
forms forhead, dorsum and apex of nose
forms nasal placodes
Nasal placodes form..
form medial and lateral nasal prominence
Medial nasal prominence
forms medial nose, upper lip, and philtrum
Lateral nasal prominence
alae of nose
Maxillary prominence
forms lateral part of upper lip, lateral jaw, and secondary palate
Nasolacrimal groove
oblique furrow formed between lateral nasal prominence and maxillary prominence
Mandibular prominence
forms lower jaw and lower lip
Mimetic muscles
muscles of facial expression from arch 2 that invade arch 1 swellings
Nose formation
nasal palcodes –> nasal pits –> nasal sac
Nasal sac
primitive nasal cavity
Oronasal membrane
separates primitive nasal cavity from primitive oral cavity
What does oronasal membrane breakdown into
primitive choanae
Intermaxillary process
forms nasal septum and primary palate
How is intermaxillary process formed
fusion of medial and nasal prominences
Primary palate
forms upper lip
How is primary palate formed
from deep portions of intermaxillary process
Incisive foramen
boundary between primary and secondary palate and distinguishes between anterior and posterior cleft deformities
How is secondary palate formed
formed by palatine shelves (lateral palatine processes)
Shelves fuse with each other and form secondary palate