salivary glands Flashcards
Saliva is involved to some degree in all of the
following functions:
Speech Mastication Taste Swallowing Digestion
saliva in digestion
salivary amylase
saliva and taste
gustin: protein thought to be necessary for growth and maturation of taste buds.
saliva function in protection
Lubrication protects lining mucosa from noxious stimuli,
bacterial toxins, and minor trauma
Washing action to rid mouth of non-adherent bacteria
Clearance of sugars from mouth
saliva buffering function
prevents?
buffers?
protein component?
Prevents potential pathogenic bacteria from colonizing the
mouth (most require an acidic pH)
Buffering of microbial acids (bicarbonate & phosphate ions)
Sialin: a protein that raises pH of dental plaque after exposure
to fermentable carbohydrates
saliva antimicrobial function/components
Lysozyme: hydrolyzes bacterial cell walls
Lactoferrin: binds free iron and thereby deprives bacteria of an essential nutrient
Salivary IgA: causes bacterial clumping (agglutination)
saliva function in tooth integrity
Calcium and phosphate ions facilitate mineralization of
tooth surface
saliva and soft tissue repair
Epithelial growth factor
Clotting factor
development of the salivary glands
dictated by?
form?
Ectomesenchymal cells dictate differentiation of oral epithelium which, in turn, proliferates and grows into the underlying mesenchyme.
The epithelial buds undergo histodifferentiation and morphodifferentiation to form assemblies of:
Alveoli that develop into acinar cells
Epithelial cords that develop into ducts
stages of salivary gland development in order, important GFs
Induction of oral epithelium by underlying ectomesenchyme
Growth of the epithelial cord
Initiation of epithelial cord branching
Repetitive branching and lobule formation
Canalization of the presumptive ducts
Cytodifferentiation to become acinar cells, myoepithelial cells,
and ductal cells
• FGF (fibroblast growth factor)
• EGF (epidermal growth factor)
developmental “equation” of salivary glands
see attatched
when do the major salivary glands develop
The parotid and submandibular glands begin to form during the
6th week of embryonic development with the sublingual gland
initiating development during the 8th week.
when do minor salivary glands develop
The minor salivary glands begin to form by the 10th week of
embryonic development.
Hierarchy of ducts starting at the level of the secreting unit (acinus):
Intercellular canaliculus Intercalated duct Striated duct Excretory duct (a.k.a. collecting duct) Terminal excretory duct
intercellular caniculi
between acinar cells
possess villi for resorbtion of water
intercalated ducts
no villi
lined with cuboidal cells
striated ducts
microvilli for electrolyte resorption and secretion
EGF secreted here
Myoepithelial Cells (a.k.a. Basket Cells):
Associated with terminal end pieces (acini) and intercalated ducts.
contractile cells
major salivary duct formal names
Parotid Gland – Stenson’s Duct
Submandibular Gland – Wharton’s Duct
Sublingual Gland – Bartholin’s Duct
parotid gland secretions, % salivary flow, enlargement occurs with?
Pure serous secreting gland
Responsible for 20% of unstimulated salivary flow
Salivary gland enlargement occurs in parotitis (mumps), Sjögrens syndrome, bulimia, anorexia, benign/malignant neoplasia.
subman gland secretion, % and frequent structure?
Mixed seromucous gland (i.e., predominately serous
with mucous contributions)
Responsible for 60% of unstimulated salivary flow.
Serous demilunes
sublingual gland secretion, % and frequent structure?
Mixed mucoserous gland (i.e., predominately mucous secreting)
Responsible for 10% of unstimulated salivary flow
Serous demilunes
minor salivary glands
Minor salivary glands account for 10% of unstimulated
salivary flow
Most minor salivary glands are mucous secreting
Named minor salivary glands are:
von Ebner’s
Blandin-Nuhn
Weber’s
Carmalt’s
von ebners
Pure serous glands associated
with the circumvallate papillae of the tongue.
Blandin-Nuhn
•
Mucoserous glands located on ventral surface at tip of tongue
•
Weber’s
Mucous glands associated with the pharyngeal tonsil
Carmalt’s
Mucous glands found in the mandibular retromolar area
Classification of Glands, definitions
• Endocrine – product secreted into blood and affects other cells;
no duct system
• Exocrine – secrete product onto a surface; usually has a duct
• Merocrine – little/no damage to secreting cells (salivary glands)
• Apocrine – partial injury to secreting cells (mammary/sweat
glands)
• Holocrine – total destruction of secreting cells (sebaceous
glands)
fordyce granules
Not a pathologic lesion
• Represent ectopic sebaceous
glands
nicotine somatitis
inflammed minor salivary glands on the palate due to excessive heat
Salivary Gland Mucocele
common places
characterized by?
The result of trauma that severs the duct resulting in extravasation of mucin into the surrounding soft tissues
Most common site of occurrence are the lips, tip of the ventral surface of the tongue and soft palate
Characterized by a accumulation of mucin containing numerous foamy histiocytes surrounded by granulation tissue
Ranula
A term used to designate a mucocele that occurs on the floor of the mouth. Ranulas most often involve the sublingual salivary gland.
Sjögren’s Syndrome disease type demographic common symptoms gland affected
Chronic, systemic autoimmune disease
80% to 90% of cases occur in middle aged females
Xerostomia, xerophthalmia or keratoconjunctivitis sicca
Parotid gland swelling due to lymphocytic & plasma cell infiltrate
mixed tumor/ pleomorphic adenoma occurrence rates, malignant or benign?
A benign tumor that accounts for 53% to 77% of parotid gland tumors; 44% to 68% of submandibular gland tumors; and 38% to 43% of minor salivary gland tumors
mixed tumor/ pleomorphic adenoma histology
shape?
tissue derived from?
other cells present?
- Well circumscribed and encapsulated
- Tissue derived from mixture of ductal and myoepithelial cells
- Keratinizing squamous cells and mucous producing cells are also present
mucoepidermoid carcinoma
malignant/benign?
most commonly affected gland? common result?
One of the most common salivary gland malignancies
Most commonly involves the parotid gland. Consequently, pain or facial nerve palsy may develop
mucoepidermoid carcinoma histology
composed of?
characterisitcs?
- Composed of a mixture of mucous producing cells and squamous epidermoid cells.
- Abundant cellular pleomorphism (altered morphology)tendency to form cystic areas within the tumor cell mass