Oral and Craniofacial Development 1 Flashcards
what period occurs in days 0-7
pre-implantation period
in the pre-implantation period, the zygote forms into a _________ and then a _________
morula
blastocyst
in days 7-14, implantation occurs and what forms
bilaminar disc
what process occurs in days 14-21
gastrulation
what process starts in days 14-21
beginning of neurulation and folding
what happens in days 21-28
closure of the neural tube and folding
Folding produces a somewhat tubular emery with ____________ around the outside, ________ lining the inside, and __________ between those two
Ectoderm
Endoderm
Mesoderm
Where does the stomodeum develop
In the ectoderm between the brain and heart
Separates the primitive oral cavity from the primitive pharynx at the beginning of the primitive gut
Oropharyngeal membrane
What emerges in week 4
Facial processes
Budges that will form the centers of growth for the face
Facial prominences or facial processes
What are the facial processes
Frontonasal process
Pair of maxillary processes
Pair of mandibular processes
In the adult, the upper face is derived from the ____________
Frontonasal process
In the adult, the midface is derived from the ____________
Maxillary processes
In the adult, the lower face is derived from the ____________
Mandibular processes
What will the Frontonasal process give rise to
Forehead, nose, philtrum, upper incisors, and part of palate
What will the maxillary processes give rise to
Temporal bones, zygomatic bones, cheeks, sides of upper lip, most of maxilla, most of palate, and upper dentition (not including incisors)
What will the mandibular processes give rise to
Lower lip, mandible, and lower dentition
The oropharyngeal membrane disintegrates so that the ___________ is open to the primitive pharynx
Stomodeum
The mandibular processes grow towards the midline and fuse to form the _____________, which will form the lower lip and mandible
Mandibular arch
The maxillary processes start to grow superiorly and anteriorly to the stomodeum, in preparation for forming most of the ___________, __________, and the ___________
Upper lip, palate, and maxilla
Areas of specialized thickened ectoderm develop at the surface of the embryo to form __________
Placodes
The nasal placodes will develop into the _________
Olfactory epithelium
The lens placodes will form the ___________
Lenses of the eye
The otic placodes will become the _____________
Internal ear
The tissue around the nasal placodes undergoes growth, and the placodes become submerged forming depressions called ____________
Nasal pits
The crescent shaped growths on the medial side of each nasal pit are known as the ______________
Medial nasal processes
The growths on the lateral sides of each nasal pit are known as __________
Lateral nasal processes
The medial nasal processes will fuse together to form piece of tissue called the intermaxillary segment which will form what
Middle of the nose from root to apex, philtrum, tubercle of upper lip, upper incisors, and part of palate
The lateral nasal processes will form the what
Lateral portions of the nose and the alae of the nose
The maxillary processes fuse with the:
Medial nasal processes to form the upper lip
Lateral nasal processes
And mandibular processes
Arise from lack of, or incomplete, fusion of various facial processes
Clefts
Clefts can be caused by:
Genetic or environmental factors
While the face is developing, what else is developing
Branchial arches
What are the tissues of the first branchial arch
Maxillary processes and mandibular processes
The maxillary processes are actually outgrowths of the _____________
Mandibular processes
The mandibular processes fuse to form the _____________, which is actually the first branchial arch
Mandibular arch
The branchial arches give rise to the structures of the:
Face and neck
How many prominent branchial arches are there in humans
4
Each arch is composed of _________ on the outer surface, _________ beneath the ectoderm, and ________ on the inner surface
Ectoderm
Mesodermal
Endoderm
The branchial arches are separated by a ___________ on the outer surface and a ___________ on the inner surface
groove/cleft
pharyngeal pouch
Pharyngeal pouches are evaginations of the ________________
primitive pharynx
Mesoderm invaded with neural crest cells becomes a special tissue called ______________
ectomesenchyme
The neural crest cells that migrate into the branchial arches contribute to the development of various craniofacial tissues, including _______________
bone and all dental tissues except enamel
Each branchial arch develops a:
*Nerve component
*Muscular component
*Vascular component
*Cartilage rod
What nerve, muscle, bone and cartilage is associated with the first branchial arch
Nerve: CN V
Muscle: muscles of mastication
Bone and cartilage: meckel’s cartilage, mandible, maxilla, incus and malleus of inner ear
What nerve, muscle, bone and cartilage is associated with the second branchial arch
Nerve: CN VII (facial)
Muscle: muscles of facial expression
Bone and cartilage: hyoid bone and stapes of inner ear
What nerve, muscle, bone and cartilage is associated with the third branchial arch
Nerve: CN IX (glossopharyngeal)
Muscle: stylopharyngeus
Bone and cartilage: hyoid bone
What nerve, muscle, bone and cartilage is associated with the fourth branchial arch
Nerve: CN X (vagus)
Muscle: pharyngeal constrictors
Bone and cartilage: laryngeal cartilages
The mucosa of the tongue forms from swellings derived from the __________
inner aspects of the branchial arches
The mucosa of the anterior 2/3rds of the tongue develops from __________
branchial arch 1
The mucosa of the posterior 1/3 of the tongue develops mostly from ____________
branchial arch 3
What are the swellings that will form the tongue
Tuberculum impar (from 1st arch)
Lingual swellings (from 1st arch)
Hypobranchial eminence (from part of 4th arch and mostly 3rd arch, overgrows 2nd arch)
from the first arch, the lingual swellings emerge during the ____ week of development lateral to the tuberculum impar
5th
The lingual swellings grow forward and merge to form the _______________
anterior 2/3 (body) of the tongue
the hypobranchial eminence forms from the _____ arch and parts of the _____ arch
3rd
4th
The hypobranchial eminence overgrows the second arch and merges with the lingual swellings to form the ________________
posterior 1/3 (root) of the tongue
the epiglottis forms from the _____ arch
4th
Area where thyroid gland develops
Foramen cecum
The body of the tongue eventually separates from the floor of the mouth, except at the ____________
lingual frenum
What occurs if the body of the tongue doesn’t fully separate from the floor of the mouth
Ankyloglossia
The intrinsic muscles of the tongue are thought to be formed from cells that migrate from the _____________
occipital somites
Occipital somites migrate into the developing tongue and bring their own nerve supply:
The hypoglossal nerve (CN XII)
Fusion of the medial nasal processes forms the ________________
intermaxillary segment
the intermaxillary segment will give rise to the __________________
middle of the nose and philtrum
Within the oral cavity, the intermaxillary segment will form the _____________, which will give rise to the anterior portion of the hard palate
primary palate
the maxillary processes grow lateral projections into the oral cavity called the _________________
palatal shelves
The palatal shelves will eventually fuse together to form the _______________
secondary palate
The secondary palate will give rise to the ________________________
posterior portion of the hard palate, the soft palate and the Uvula
The primary palate grows to meet the _________________
palatal shelves
The palatal shelves fuse to form the __________________
secondary palate
The primary palate and secondary palate eventually fuse to complete the ________________
entire palate
When does lifting of the head occur
Week 7-9
Rotating/lifting of the head helps the tongue move out of the way so that the palatal shelves can grow in what direction
Down
The medial nasal processes give rise to the:
Middle of the nose
Philtrum
Tubercle of upper lip
Maxillary incisors
Anterior of hard palate
The maxillary processes give rise to the:
Cheeks
Labial commissure
Sides of the upper lip
Maxillary canines & posterior teeth
Posterior of the hard palate
Soft palate
Uvula
all teeth will arise from the _____________, except for the upper incisors, which will arise from the medial nasal processes
first branchial arch
All teeth will develop from interaction between the surface _________ and underlying __________ in these areas
ectoderm
ectomesenchyme
