Oral mucosa up to slide 13

Oral mucosa

Mucous membrane: moist lining of body cavities that communicate with the exterior

Oral mucosa: mucosa/ mucous membrane lining the oral cavity with many functions such as: protective, sensory, & secretory

Epithelium: AVASCULAR; basic tissue types that covers & lines the external & internal surfaces

ORAL Epithelium: avascular, superficial layer of oral mucosa (overlying the CT tissue proper OR lamina propria)

Basement Membrane: extracellular material consisting of a basal & reticular lamina produced by epithelium & CT

  • Thin acellular bm located between epithelium & CT

Connective Tissue CT: basic tissue type composed of cells & matrix as well as other component

  • Connects & supports other tissues

Oral mucosa CT PROPER: supportive layer of CT aka. Lamina propria, underlying epithelium

FUNCTIONS AS: mechanical support layer because of density/ arrangement of blood supply

Oral Mucosa:

Oral cavity: mirror that reflects the health of the individual

WHY? Can reveal signs of underlying health issues


←  Stratified Squamous Epithelium overlying a CT PROPER OR lamina propria, with a possible deeper submucosa 



Oral Mucosa Properties: The clinical appearance of tissue reflects the underlying histology for healthy/ normal or diseased patients

Basement membrane = “extracellular materials” 2 layers:

  1. Basal lamina (superficial) produced by epithelium

  2. Reticular lamina (deeper) produced by CT

 thin, acellular structure between epithelium & CT (of oral mucosa & skin)

  • Continuously lines the oral cavity; connecting structures and linking the two

COMPOSED OF: stratified squamous epithelium overlying a CT PROPER, or lamina propria, with possibly a deeper submucosa


Changes indicative of disease are seen as alterations in the oral mucosa, revealing:

  • Systemic conditions such as:

    • Diabetes

    • Vitamin deficiency

  • Local effects of chronic tobacco/ alcohol use

Q:Oral Mucosa is composed of Stratified Squamous Epithelium OVERLYING Connective Tissue

FUNCTIONS: mucosa/ mucous membrane lining oral cavity

  • Protects us from mechanical forces

  • Act as barrier to: pathogens

  • sensory (taste & pressure)

  • absorption (Nitroglycerine)

  • secretion (salivary glands)

  • esthetics

**Keratinized = greater protection than NON-Keratinized


Stratified Squamous Epithelium = “EPIDERMIS”

an overlying CT PROPER (lamina propria) = “DERMIS”

  • CT makes up BULK of skin & oral mucosa

    • Regional differences occur

Q: Oral Mucosa is specifically made of Stratified Squamous Epithelium

Q: Although regional differences occur, Connective Tissue makes up the bulk of oral mucosa

Structure of Oral Mucosa: TWO Basic Tissue Types REVIEW:

  1. Epithelium → ORAL EPITHELIUM - superficial layer of oral mucosa overlying the CT PROPER (lamina propria)

    1. Stratified Squamous Epithelium

  2. CT → CT PROPER = LAMINA PROPRIA - underlying supportive layer beneath epithelium

    1. FUNCTIONS: mechanical support because of density & allow arrangement of blood supply


TYPES of Oral Mucosa (3) Main Types: found in oral cavity

Classification of oral mucosa is based on the General Histologic Features of the tissue

  1. Lining: Soft palate 

    1. buccal & labial

    2. Alveolar mucosa

    3. Ventral surface of tongue

    4. Floor of mouth

  2. Masticatory: Hard palate

    1. attached gingiva

    2. Dorsal surface of tongue

  3. Specialized mucosa: dorsal & lateral tongue


Lining Mucosa: Regions****

Alveolar Mucosa: part of oral mucosa immediately apical to the mucogingival junction

Buccal Mucosa: mucosa lining the inner cheeks

Labial Mucosa: mucosa lining inner portions of the lips

Floor of the Mouth: horizontal horseshoe shape area beneath the tongue.

  • Above mylohyoid muscle (makes up most of floor of mouth) and posteriorly toward the anterior tonsillar pillar

Ventral Surface of Tongue: undersurface of tongue

  • Closest to floor of mouth

Soft Palate: posterior ⅓ of palate = VELUM

  • Back of the roof of the mouth 


General Clinical Appearance: 

  • Softer surface texture & moist surface

  • Ability to stretch and be compressed, acting as cushion

General Histological Features: allows mucosa to serve in regions of the oral cavity where a movable base is needed such as during:

  1. Speech

  2. Mastication

  3. swallowing

NONKERATINIZED EPITHELIUM with smooth interface, few rete ridges & CT Papillae with elastic fibers in lamina propria & submucosa overlying muscle