Oral bio CA2

What areas of the oral mucosa have keratinized epithelium?

Hard palate, gingiva (attached gingiva), dorsal tongue (filiform papillae).

What areas of the oral mucosa have non-keratinized epithelium?

Soft palate, buccal mucosa, floor of mouth, ventral tongue, sulcular epithelium.

What is a key difference between keratinized and non-keratinized epithelium?

Keratinized has a granular layer and superficial keratinized layer, while non-keratinized retains nuclei in outer layers.

What protein provides structural support to the epithelium?

Cytokeratin.

What is the first fiber to form in connective tissue?

Collagen fibers (type I).

What gives gingiva its color?

Vascularity, melanin pigmentation, and thickness of epithelium.

Which layer of the oral mucosa contains progenitor cells?

Basal layer (stratum basale).

What is the function of desmosomes in epithelial tissues?

Desmosomes connect epithelial cells to each other.

What do hemidesmosomes anchor?

Anchors epithelial cells to the basement membrane.

What causes stippling in the periosteum?

Collagen fiber bundles inserting into the bone creates an uneven surface.

Are sebaceous glands normal in oral epithelium?

No, they are ectopic (e.g., Fordyce granules).

Where are taste buds located?

Tongue (fungiform, circumvallate papillae), soft palate, pharynx, epiglottis.

Which areas of the tongue detect sweet and salty tastes?

Tip of the tongue.

What nerve innervates the anterior 2/3 of the tongue?

Lingual nerve (V3) and taste via chorda tympani (VII).

What nerve innervates the posterior 1/3 of the tongue?

Glossopharyngeal nerve (IX).

What defines the vermillion zone of the lips?

It is the red border with thin keratinized epithelium and high vascularity.

How does skin differ from oral mucosa?

Skin is thick, keratinized, has hair and sweat/sebaceous glands. Oral mucosa is thinner, mostly non-keratinized, and has minor salivary glands.

Where is the thinnest epithelium found in the oral cavity?

Floor of the mouth.

What is the hardest area of oral mucosa?

Masticatory mucosa (gingiva and hard palate).

What type of epithelium forms the junctional epithelium?

Attaches with hemidesmosomes to the tooth surface.

What cells are responsible for forming enamel?

Ameloblasts.

How many dentin tubules does one ameloblast induce?

One ameloblast induces one dentin tubule.

What is the main collagen type found in dental structures?

Type I collagen.

What does HERS become after development?

Cell rests of Malassez.

What are the two types of cementum?

Acellular (near CEJ) and cellular (apical).

What is the majority cell type found in pulp?

Fibroblasts.

What are the variations of the cementum-enamel junction (CEJ)?

60% overlaps enamel, 30% edge-to-edge, 10% gap.

What is the most accepted theory of root development?

HERS (Hertwig’s Epithelial Root Sheath) guides root shape.

What are osteoblasts responsible for?

Building bone.

What hormone increases osteoclast activity?

Parathyroid hormone (PTH).

How thick is the mandibular anterior bone?

Thin, posing a risk of perforation during implants.

What are the normal serum calcium and phosphate levels?

Calcium: 8.5–10.5 mg/dL, Phosphate: 2.5–4.5 mg/dL.

What substances aid and inhibit calcium absorption?

Vitamin D aids; phytates, oxalates inhibit.

What hormonal deficiency causes enamel hypomineralization?

Vitamin D deficiency (rickets).

Is interglobular dentin hypo- or hypermineralized?

Hypomineralized.

When does tertiary dentin form?

After trauma or inflammation.

Where is mantle dentin located?

Nearest to the dentin-enamel junction (DEJ).

What is the difference between enamel rods and interrod enamel?

Rods are hypermineralized; interrod enamel is less mineralized.

How does surface enamel differ from enamel near the DEJ?

Surface enamel is more mineralized and has fewer rods; DEJ is less mineralized and scalloped.

What is the function of amelogenin?

Guides enamel mineralization.

What role does the gubernacular cord play in tooth development?

Guides permanent tooth eruption.

What are the phases of eruption?

Pre-eruptive, eruptive, post-eruptive.

What cells are responsible for the formation and removal of bone and cementum?

Formation: osteoblasts, cementoblasts; Removal: osteoclasts.