Histology Lecture 3a -- Oral Mucosas Flashcards
Describe the epithelium of the skin on the face
Stratified squamous epithelium, keratinized and shows hair follicles, sebaceous glands, and sweat glands
Layer beneath the epithelium of the skin
Connective tissue layer called the dermis
2 layers of the dermis of the skin
Papillary layer
Reticular layer
Describe the organization of the papillary layer
Interdigitated with the rete pegs of the epithelium
Layer contained in the skin epidermis
Stratum granulosum layer with basophilic keratohyalin granules
Define stratum corneum of the skin
Dead cell layer that is orthokeratinized
Define orthokeratinized
The usual or true form of keratinization
Define the red border of lip
A transitional region from dry to wet surface epithelium (dry skin-type epithelium becomes the wet oral mucous membrane or oral mucosa)
What layer is the lamina propria of the oral mucosa continous with at the level of the lips
The dermis of the skin
Describe the keratinization of the lips
Epithelium is partially keratinized, so keratinized near the skin, but non-keratinizaed near the oral mucosa
The keratinized layer is thin, making the epithelium translucent
Describe the dermis/lamina propria of the lips
Rete pegs are very deep and the vessel-containing papillae of the lamina propria extend very close to the lip surface
Describe the anatomical location of the oral mucosa
Entire inside of the mouth except for the gingiva and the dorsal surface of the tongue
Describe the epithelium of the oral mucosa
Stratified squamous epithelium, nonkeratinized
Surface cells of the epithelium are squamou but contain nuclei and desquamate as living cells into the oral cavity
Describe the lamina propria of the oral mucosa
Very vascular (reason for deep red color of mucosa)
Layer beneath the lamina propria of the oral mucosa and its contents
Submucosa, which has small glands that constitute the minor salivary glands (may be serous, mucous or mixed)
Define the anatomical location of gingiva
gums surrounding the teeth and cover the entire hard palate
Define the mucogingival junction
Where the oral mucosa nad gingiva meet at a visible line in the mouth
Describe the epithelium of the gingiva
Modification of the stratified squamous epithelium. Has a stratum germanitavum and a stratum spinosum layer, but no stratum granulosum. Spinosum cells flatten and become keratinized, but do not die. They retain their nuclei until they desquamate.
Define parakeratinization
Type of keratinization found in the gingiva wherein the spinosum cells of the epithelium flatten and become keratinized, but do not die. Instead, they retain their nuclei (thin, flattened and not obvious) until they desquamate. Form a thick regular layer that stains deeply eosinophilic
What layer is the submucosa of the gingiva and hard palate continuous with?
Periosteum lining the alveolar bone or the palatine process of the maxilla (therefore the gingiva does not move freely over the bone)
Define the junctional epithelium of the gingiva
Gingiva reflects onto the tooth surface and the cells become modified for attachment to the tooth surface
What does the formation of the junctional epithelium of the gingiva involve?
Formation of hemidesmosomal attachments to the calcified surface of the tooth (can be to either the enamel or the cementum)
What is the only seal separating the “dirty (bacteria, etc)” oral cavity from the “inside” lamina propria and blood vessels supplying the gingiva?
Hemidesmosomal attachments
2 subdivisions of the palate
Hard palate
Soft palate
What underlies the mucosa of the hard palate?
Bone
What underlies the mucosa of the soft palate?
Skeletal muscle
Describe the mucosa of the palate
Masticatory mucosa similar to that of the gingival (i.e. with a stratified squamous parakeratinized epithlium). Reflects around the soft elastic palate and the uvula where it is a stratified squamous nonkeratinizing epithelium, to become respiratory epithelium (pseudostratified ciliated columnar) on the nasal side of the palate.
How is the mucosa attached to the palatine bone in the hard palate region?
By a mucoperiosteum
Where can salivary glands be found in the palate?
Laterally in the mucosa