Oral Cavity Flashcards
what is the oral fissure?
the opening of the mouth
what is the oral cavity?
the space that the mouth opens on to up until it transitions to the oropharynx
what is the oral vestibule?
the space between the cheeks and teeth
what is the oral cavity proper?
the space inside the teeth; where the tongue is
what are the borders of the combined oral cavity?
- superior border - hard and soft palate
- posterior border - oropharyngeal isthmus
- inferior border - mucous membrane covering mylohyoid muscle; occupied mainly by tongue
- anterior border - lip
- lateral walls - cheeks
what is the basic function of the oral mucosa?
provide a useful moist surface
does the oral mucosa contain hair follicles, sweat glands, or sebaceous glands?
- no hair follicles
- sweat glands present
- a few sebaceous glands present
describe the epithelium of the oral mucosa
- stratified squamous, both keratinized (ortho and para) and non-keratinized
- derived from ectoderm
- renewed every 1-2 weeks
describe the lamina propria of the oral mucosa
- underlying connective tissue
- CT papillae interdigitate with epithelial ridges, called “rete pegs”
- contains many lymphocytes in loose aggregates, as well as the tonsils: 3 x 10^9 PMNs daily
- contains small mixed sero/mucous salivary glands
what are rete pegs?
they hold the epithelium to the underlying lamina propria
describe the characteristics of rete pegs found in the lining mucosa vs. masticatory mucosa
- lining mucosa: flatter, rounded rete pegs
- masticatory mucosa: sharper, more pronounced rete pegs
what are the 3 main divisions of the oral mucosa?
- lining mucosa
- masticatory mucosa
- specialized mucosa
describe the lining mucosa
- non-keratinized
- lacks stratum granulosum (lacks keratinhyaline granules)
- cheeks
- inside of lips
- floor of the mouth
- ventral tongue
- soft palate
describe masticatory mucosa
- keratinized
- gingiva
- parts of the dorsum of the tongue
- hard palate
describe specialized mucosa
taste buds on the dorsal and lateral surfaces of the tongue
T or F:
the oral mucosa structure is similar to the rest of the GI tract
false
describe the structure of the general oral mucosa
- generally has a submucosa
- different fromthe rest of the gut
- may or may not attach to bone
- generally lining mucosa
describe the structure of the oral mucoperiosteum
- medial hard palate and attached gingiva
- no submucosa
- robust lamina propria attaches directly to bone
describe orthokeratinized tissue
no nuclei visible in keratin layer
describe parakeratinized tissue
some nuclei retained in keratin layer
describe non-keratinized tissue
no keratin
describe the relationship between orthokeratinized and parakeratinized tissues
they differ based on the presence or absence of nuclei in the keratin layer, but the difference between the two is rarely totally clear cut and they can transition back and forth
what are 4 important layers of the epidermis?
from apical to basal:
- stratum corneum
- stratum granulosum
- stratum spinosum (prickle)
- stratum basale
describe the stratum corneum
- anucleate then acellular layer of stacks (squames) of cross-linked keratin coated with lipid
describe the stratum granulosum
- keratohyalin granules - keratin aggregation
- lamellar granules - lipid coating
- non-keratinized tissues will lack this layer