oral histo quiz 2

what week do we see medial and lateral processes

wk. 5

what is the stomodeum lined with

ectoderm

what is the pharynx lined with

endoderm

neurocranium

-composed of cartilages and placodes which are supportive and related to the brain

-chondocranium + dermocranium

viscerocranium

-branchial arches and their derivatives (jaws and gills)

chondrocranium

-cartilage that protects and supports the brain

dermocranium

-true bone forms

-protective shell around the chondrocranium

how is the neurocranium different in mammals

-the dermocranium sits on top of the chondrocranium, this allows for expansion

what does the hindbrain develop into

-rhombomeres (series of 8 bulges)

what are somatomeres

-partially segmented paraxial mesoderm

what does mesenchyme develop into

-connective tissue and skeletal tissue

(loosely organized mesodermal, embryonic tissue)

what is ectomesenchyme derived from

neural crest cells

what does ectomesenchyme develop into

-dental and skeletal tissues of the oral cavity adn branchial arches

what does the midbrain and Rhb 1 & 2 provide material for

-bone and cartilage of the face

-1st branchial arch

what do NCC that arise from Rhbs 4,6, & 8 supply

-branchial arches 2-4

what is odontogenic epithelium

-tooth forming epithelium

-stimulates mesenchyme to develop dentin

what week does the buccopharyngeal membrane rupture

wk. 4

what are olfactory placodes, and when does formation begin

thick plates of cells that develop into the olfactory region of the nasal cavity

-wk. 4

nasal development is seen in what week

wk. 5

what week does the nasal pit form

wk. 5

nasal pit formation

-ectodermal cells of the nasal placode proliferate and push into the underlying NCC derived mesenchyme of the frontonasal proces

what epithelium forms the nasal pit

-invaginated sac of ectodermal epithelium

what does the medial nasal process and the frontonasal process give rise to

-mid portion of both the nose and upper lip (soft tissue)

-premaxilla and primary palate (hard tissue)

when does merging and fusion of facial processes occur

-wk. 6

what pushes the naso region toward the midline and when does this occur

-maxillary process

-end of wk. 6

what does the growth of the maxillary process form

-naso-optic groove

-bucconasal groove

what forms the upper lip

-2 maxillary processes

-2 medial nasal processes

what forms the lower lip

fusion of the mandibular process

what region carries the upper incisors

premaxilla

what forms the ethmoid bone

-trabecular cartilages

what does the basal plate form

-sphenoid and occipital bones

when does the formation of the nasal fin occur

wk. 6

what forms the nasal fin

-fusion of the medial nasal process with the maxillary process

what forms the oronasal membrane

-thinning of the nasal fin

what does the complete breakdown of the nasal fin form

-primitive choana

what week does the primary choanae form

wk. 6

what forms the nasolacrimal duct

naso-optic groove

frontonasal process forms what

medial and lateral nasal processes

what forms an intermaxillary segment which ends up forming what

-medial nasal process

-upper lip (philtrum)

-upper jaw

-primary palate -> premaxilla

the maxillary process forms what

-upper lip

-upper jaw -> maxilla

-secondary palate

when does the formation of the secondary palate begin

-wk. 7-8

-ends at 3 months

what 3 major outgrowths appear during the development of the secondary palate

-nasal septum

-frontonasal process

-palatine shelves

what defines the primitive mouth

-1st branchial/pharyngeal arch

which cleft type is the most common

-cleft lip and palate

(bilateral clefting is least common)

what results in orofacial clefting

-lack of maxillary and palatal fusions