Exam 3 - Salivary Glands Colombo Flashcards
Specialized mucosa covers the:
Anterior 2/3 of the dorsal tongue
There are several types of ____ on the tongue, some of which contain taste buds
Papilla
Papilla are specialized:
Epithelial structures
What types of papillae are found on the tongue?
- Filiform papillae
- Fungiform papillae
- Foliate papillae
- Circumvallate papillae
Filiform papillae
- Majority, predominant in body of the tongue
- no taste buds
Fungiform papillae
- larger than filiform papillae
- mostly at tip of tongue
- taste buds on upper surface
Foliate papillae
- along posterior sides of the tongue
- not very prominent in adult humans
- taste buds on sides in crypts
Circumvallate papillae
- along the junction of the body and base of tonsillar area of the tongue
- quite large
- taste buds
Filiform has what kind of epithelium?
Keratinized epithelium
Most numerous type of papillae on the tongue
Filiform
Filiform papillae are used for:
Gripping food
Fungiform papillae have what kind of epithelium?
Nonkeratinized epithelium
Foliate papillae have what kind of epithelium?
Nonkeratinized epithelium
Circumvallate papillae have what kind of epithelium?
Keratinized epithelium
How many circumvallate papillae are usually there on the tongue?
Only 10-12 of them
Circumvallate papillae contain taste buds down in ___and are associated with ____ which are serous salivary glands that wash out the crypts
Crypts; von Ebner’s glands
What are taste buds?
- specialized sensory cells, composed of a cluster of chemoreceptive spindle cells
- mostly in papillae but some around soft palate/pharynx
Taste buds are a ____ shaped structure
Barrel
Where do the apical ends of taste buds terminate?
Just below the surface in the taste pit
The taste pit communicates with the surface through the ____
Taste pore
Where do different taste signals come from?
From binding different receptors, which trigger various signaling cascades
True or false: there are distinct regions for different tastes
False - no distinct structural regions for different tastes, likely due to distribution of receptor expression
What is the major secretion of the oral cavity?
Saliva
Saliva functions
- Lubricates the mouth via mucous secretion
- Buffering: bicarbonate, phosphate ions protect the teeth against demineralization
- Digestion: begins digestion of carbohydrates via salivary amylase in serous secretion
- Protection: washing action for bacteria and sugars, helps prevent infection
Saliva contains ____ which begins the process of digestion of carbohydrates in the mouth
Salivary amylase/a-amylase
Saliva contains ____ which help prevent infections
- lactoferrin
- lysozyme
- defensins
- transport IgA
Three major pairs of salivary glands
- parotid glands
- submandibular glands
- sublingual glands
Parotid gland secretion is mostly
Serous
Submandibular gland secretion is mostly
Serous but some mucous
Sublingual gland secretion is mostly
Mucous (but is mixed secretions)
There are some minor salivary glands scattered everywhere throughout the oral cavity, such as:
- tongue (Von Ebner’s glands)
- palate
- lining mucosa
Salivary glands consist of:
Epithelial cells held together in a structure by connective tissue
Where are the epithelial cells found in salivary glands?
in the main secretory component; lines the ducts that carry the saliva
What is the function of connective tissue in the salivary glands?
Holds epithelial components in place and forms them into a discrete gland
Salivary gland development is analogous to the development of ____
Teeth (epithelium invades underlying ectomesenchymal tissue)
invading epithelium branches multiple times before forming secretory machinery
What is the main distinction between different salivary glands?
Whether they contain mucous or serous secreting cells
_____ secrete mucous
Mucous cells
Serous cells secrete:
Thinner, protein rich fluid
Serous secreting cells stain _____ than mucous cells due to the ____
darker; higher protein content
What is the largest salivary gland?
Parotid gland
The parotid glands secrete ____ of passive saliva volume
25%
What does ‘passive” mean regarding passive secretion?
Background salivation, not directly stimulated
Parotid gland secretes ____ almost exclusively
Serous
The parotid gland secretes what digestive enzyme?
a-amylase (salivary amylase)
Which salivary gland particularly contributes during active salivation?
Parotid gland (50%)
The parotid gland uses the ____ to secrete into the oral cavity
Stenson’s duct
Submandibular gland is located:
Beneath the floor of the mouth
True or false: the submandibular gland is a mixed gland
True
The submandibular gland is a mixed gland that produces more ___ than ___
More serous secretion than mucous
The serous secretion of the submandibular gland contains ____ and the mucous secretion contains ____
Amylase; mucin
The submandibular gland has a big contribution to _____ salivary volume
Background
The submandibular gland uses the ___ to enter the oral cavity at the _____
Wharton’s duct; sublingual caruncle
Where is the sublingual gland located?
Beneath the tongue
Smallest salivary gland
Sublingual gland
The sublingual gland produces ___ secretion
Mixed (more mucous than serous)
The sublingual gland is associated with what ducts?
- Ducts of Rivinus
- Duct of Bartholin
The ducts of Rivinus drain into:
areas around the floor of the oral cavity
The Duct of Bartholin (largest) drains into
Sublingual caruncle
Salivary gland structure/how secretions are pushed out
- series of branched ducts which have secretory, contractile end pieces
- saliva is deposited at one end, flows through duct system, modified at various points, and is pushed out into the oral cavity
__ cells are mixed in with the secretory cells to contract and push saliva out
Myoepithelial cells
The end product of saliva is ____ and contains ____
Hypotonic; grip of enzymes and bicarbonate
Saliva is produced and passes through structures in this order:
- Acinus
- Intercalated duct
- striated duct
- interlobular (excretory duct)
- Main excretory duct
Acinus
Berry in latin. the secretory part (serous, mucous, or both)
Intercalated duct
Moves secretions from acini to striated duct
Striated duct function
- Reabsorption of electrolytes
- preservation of salivary volume
Interlobular (excretory) duct function
Conduit to move saliva along
Main excretory duct function
Deposits saliva into oral cavity
Nervous system initiation of salivary secretion involves:
- afferent stimulation of CN 7 and 9 along with higher centers (visual and olfactory processing)
- efferent activation via parasympathetic CN 7 and 9; sympathetic input from cervical ganglion
Parasympathetic ____ salivary volume
Increases
Sympathetic ____ mucous and protein secretion
Increases
Mixed acini often contains:
Serous demilunes (appear moon shaped due to histological presentation)
What are acini and what do they produce?
- Little groups of serous cells that are interspersed with mucous secreting cells
- produce lot of proteins, lots of secretory machinery
Proteins in the saliva such as lysozyme and amylase can:
Disrupt viral capsules and bacterial cell walls
Acinus mechanism of salivary secretion
- Ach activates mass release of calcium in the acinar cells
- Calcium current causes chloride channels to open
- chloride floods into the lumen
- Aquaporins open up simultaneously to allow passive transport of water from the cell into the lumen
- chloride increasing in the lumen causes sodium and water to leak across tight junctions
- flow of sodium increases water moving through aquaporins
During salivary secretion, saliva flows first into ____ and then onto ____
Intercalated ducts; striated ducts
____ ducts have simple cuboidal epithelium
Intercalated ducts
Intercalated ducts are associated with the acini of:
Pancreas and salivary glands
True or false: intercalated ducts contribute a lot to secretion
False
____ ducts have simple columnar epithelium
Striated
Striated ducts are more specific to ____ and modify the saliva by secreting ____ and absorbing ____
salivary glands; bicarbonate; Na+ and Cl-
Collectively, the intercalated ducts and striated ducts are known as:
Intralobar ducts (they are collecting saliva from lobules of the same lobe)
What happens to saliva before it is secreted into the oral cavity?
- sodium is reclaimed via active transport in the striated duct
- chloride also recovered
- inward flow of potassium
- bicarbonate added
Bicarbonate importance
Buffers the oral environment
Saliva is ____ compared to plasma due to the loss of _____
Hypotonic; NaCl
The junctions along the striated duct are:
Water impermeable
What happens to salivary flow during sleep?
Reduced but not stopped
Salivary flow rate is approximately ____ unstimulated. During sleep it is ____. During active secretion it can increase to ____
0.3-0.4 ml/min; 0.1 ml/min; 2-5 ml/min
Unstimulated, most of the saliva comes from the:
Submandibular gland
Stimulated, the _____ gland becomes the major contributor and contains a lot of _____
Parotid; bicarbonate
Salivary pellicle
Coating of salivary components on the tooth surface, including bicarbonate, glycoproteins, proteins
Salivary pellicle is also called:
Acquired pellicle
Proteins of the salivary pellicle - function
Antimicrobial properties that can make enamel less vulnerable to acid attack
Saliva is rich in _____ which aids in mineralization
Calcium and phosphate ions
What can disrupt the salivary pellicle?
Prophy cleaning
Xerostomia
Dry mouth
Xerostomia deprives the tooth of the:
Protective salivary pellicle and buffering capacity
Xerostomia increases the risk of
More loss of mineralized tissues
With age there is a gradual loss of ___ acinar cells
30-60%
Sjogren’s syndrome
Autoimmune disease where lymphocytes invade the salivary gland and destroy epithelial cells
Tx for dry mouth
- sipping water constantly
- artificial saliva
- parasympathetic stimulating drugs to increase flow
