oral and nasal cavity Flashcards
locate:
- tubercule
- philtrum
- vermillion border
- labial commissure
- vermillon zone
- tubercule: bump in the middle of upper lip
- philtrum: between upper lip and nose
- vermillion border: left and right side of upper lip
- labial commissure: corner where lips meet
- vermillion zone: middle of upper lip to middle of bottom lip
which prominences come from pharyngeal arch 1?
- maxillary
- mandibular
define diverticulations
form from outgrowths of nasal cavity
what are the four sinuses and when do they form
- maxillary: late pregnancy
- frontal: 2 years old, from the ethmoid sinus
- ethmoid and sphenoid: after birth
what is the purpose of a sinus
- humidifies air
- speech
- lightens cranium while maintaining strength
describe the lining of the nasal cavity
- pseudostratified columnar epithelium with cilia
- goblet cells which rest on basement membranes
- vascular lamina propia: warms the air
how does the paranasal sinus differ from the nasal cavity?
- it is thinner than the nasal mucosa
- fewer goblet cells
what are the olfactory epithelium differences?
- bipolar olfactory nerve cells
- formed from ectoderm
- attach to olfactory bulb
what is a symphisis
thin line of cartilage that separates 2 bones or cartilage
define meckel’s cartilage
cartilage of the first branchial arch associated with the formation of the mandible
what happens at the 6 week mark in mandible formation?
- meckels cartilage forms a rod surrounded by a fibrocellular capsule
- the 2 cartilages do not meet at midline, they are separated by a symphisis
- on the lateral aspect of the symphisis, a condensation of mesenchyme forms
what happens at the 7 week mark in mandible formation?
- intramembranous ossification begins in the mesenchyme and spreads to form the bone of the mandible
- bone spreads anteriorly to the midline of the developing lower jaw
- bones do not fuse a midline, they are separated by a symphisis
- symphisis fuses shortly after birth
where does the mandibular symphisis form from? when does it fuse
- meckels cartilage
- shortly after birth
how and when does the ramus develop?
- develops from rapid ossification posteriorly into the mesenchyme of the first arch
- 7 weeks
what type of ossification forms the mandible?
intramembranous
when does palate formation begin?
6 weeks
describe primary palate formation
- median nasal processes fuse and form:
- intermaxillary segment
- median palatine process
- fuses to form the primary palate
- intermaxillary segment
what must happen for the oral and nasal cavities to be distinguishable?
the secondary palate must develop
what binds the common oronasal cavity anteriorly? what is it occupied by?
- the primary palate
- occupied by developing tongue
what makes up the secondary palate?
hard and soft palate
what do the maxillary processes form? what direction do they form?
- lateral palatal processes
- fuse from anterior to posterior
what outgrowths appear in the oral cavity?
- nasal septum
- two palatine shelves
what happens to the nasal septum in the oral cavity?
- grows downward through through the oral cavity
- encounters the primary and secondary palates
what is the result of the closure of the secondary palate?
- hardening of the palatine shelves
- vacation of the tongue
