Histology Flashcards
Oral Cavity
- vestibule
2. oral cavity proper
Vestibule
space b/w lip, cheeks, teeth
Oral Cavity Proper
hard and soft palates, tongue, floor of mouth, and entrance to oropharynx
3 major paired salivary glands
-parotid
-submandibular
-sublingual
have ducts that open into oral cavity
3 types of mucosae that lines oral cavity
- masticatory mucosa: gingiva and hard palate
SSE Keratinized (SSE parakeratinized) epithelium - specialized mucosa: dorsum of tongue, has papillae SSE Keratinized Epithelium
- lining mucosa: everything else, lips, cheeks, mouth floor, alveolar region, soft palate SSE nonkeratinized epithelium
4 types of papillae on tongue
- Filiform papillae (SSE-K) no taste buds, most numerous
- Fungiform papillae, may be keratinized, taste buds
- Circumvallate papillae, taste buds
- Foliate papillae, taste buds
Filiform Papillae
-smallers & most numerous over entire anterior 2/3 of tongue in rows, NO taste buds
3 cells in taste buds
- sensory cells: elongated, predominate, synapse w afferent nerve fiber
- supporting cells: elongated
- basal cells: short, stem cells for sensory and supporting cells
Taste Buds
- sweet, salt, sour, bitter, umami
- one type of sensory receptor per sensory cell
- buds have mixtures of sensory cell types
- bitter is in back on tongue
- all others are all over
- 2000 per tongue
- few are found on roof, post tongue, epiglottis, esophagus, pharynx
Serous Cells
in salivary glands
-secrete watery substance with protein, amylase, and lysozyme, have basal basophilia, many granules in apical cytoplasm
Mucous Cells
secrete mucus, which is lost during preparation so that apical region looks empty, nucleus typically flattened at base of cell
Organization of Salivary Glands
- clusters of cells are organized into acini or alveoli
- myoepithelial cells
- secretions by acini cells is extruded by contraction of myoepithelial cells
- ducts
Ducts in Salivary Glands
- intercalated: originate from acini, secrete and absorb, simple cuboidal, small & modifies the secretion
- striated: simple cuboidal to simple columnar cells, striations caused by basal plasma membrane, around size of acinus or larger, modifies secretion
Myoepithelial Cells
-elongated contractile cells that surround the epithelial basal lamina
Parotid Gland
-purely serous acini
Submandibular Gland
mixed, but mostly serous
in mixed glands, mucous cells exist as either purely mucous acini or mixed acini in which serous cells form a cap called serous demilune
Sublingual
mixed, mostly mucous
Saliva
- mixture from all glands
- 1200mL per day
- bicarbonate ions buffer content in oral cavity
- digestive enzymes
- wash away harmful stuff, lubricates, Ca, P, protective film for teeth, medium to food to stim taste buds, abs
Whats in Tubular Part of Alimentary Tract
-esophagus, stomach, small intestine, large intestine
Tubular: Mucosa
lining epithelium, lamina propria (lymphatic tissue), and muscularis mucosae
Tubular: Submucosa
consisting of dense irregular connective tissue
Tubular: Muscularis Externa
2-3 layers of smooth muscle
Tubular: Serosa
Squamous epith and CT or adventitia consisting of CT
Principle Functions of Mucosal Layer
- secretion
- absorption
- protection
