Salivary glands

Question 1

What does salvia do for protection?

Answer 1

Liquid flushes away non-adherent bacteria, debris, sugars, etc. Mucins provide lubrication for oral tissues to move over one another

Question 2

what does salvia do for buffering?

Answer 2

Bicarbonate protects teeth from bacterial acids

Question 3

what does salvia do for tooth integrity?

Answer 3

High levels of calcium and phosphate helps enamel to mature and increases hardness and resistance to demineralization

Question 4

what does salvia do for antimicrobial activity?

Answer 4

Mucins provide a barrier; a number of proteins have antibacterial properties (e.g. lysozyme); immunoglobulins agglutinate bacteria

Question 5

what does salvia do for digestion?

Answer 5

Fluid and mucin components aid in the formation and swallowing of a food bolus; enzymes such as amylase begin the process of breaking food down

Question 6

what does salvia do for taste?

Answer 6

Saliva helps solubilize food so that it can interact with taste receptors

Question 7

what are the 3 pairs of salivary glands?

Answer 7

• parotid glands
• submandibular glands
• sublingual glands

Question 8

Describe parotid glands.

Answer 8

Largest salivary glands.
Pyramidal shape with apex below angle of mandible, posterior edge is near external auditory meatus.
Parotid duct emerges from the anterior border, passes over masseter and pierces buccinator, emptying into the oral cavity on a papilla opposite the upper second molar tooth.
External carotid artery, retromandibular vein and facial nerve are all embedded in the gland

Question 9

what is the parasympathetic innervation of the parotid gland?

Answer 9

Preganglionic: glossopharyngeal - lesser petrosal nerve- otic ganglion
Postganglionic:
otic ganglion- auriculotemporal nerve - parotid gland

Question 10

Describe submandibular glands.

Answer 10

Superficial part visible below inferior border of the mandible, the gland wraps around the posterior border of the mylohyoid muscle, where there is a smaller deep portion of the gland.
Submandibular duct emerges from the deep part of the gland and passes forward to terminate on the sublinqual caruncle near the base of the lingual frenum.
Facial artery grooves the superficial part of the gland

Question 11

what is the parasympathetic innervation of submandibular and sublingual glands?

Answer 11

Preganglionic: facial nerve - chorda tympani - lingual nerve - submandibular ganglion
Postganglionic: submandibular ganglion - submandibular gland

Question 12

Describe sublingual glands.

Answer 12

Almond shaped, it sits in the sublingual fossa of the inner aspect of the mandible, bounded above by the oral mucosa, below by the mylohyoid muscle, and medially by the genioglossus muscle.
The sublingual ducts vary, but typically the anterior part drains via a single duct that joins the submandibular duct, and the posterior part drains via several small ducts that end on the sublingual fold

Question 13

Describe a stroma.

Answer 13

Covered by a tough connective tissue capsule with septa of connective tissue that pass inward and subdivide the gland into lobes, that in turn are subdivided into lobules. Blood vessels, nerves and major ducts travel in these septa

Question 14

Describe a parenchyma.

Answer 14

Compound tubulo-acinar glands.
Secretory elements consist of serous acini, mucous acini and mixed acini, although the type present depends upon the gland.
Secretion produced by merocrine secretion

Question 15

what are the two classifications of salivary glands?

Answer 15

Serous- thin watery secretion that contains proteins
Mucous- secrete mucin, which consists of a protein core that is highly decorated with sugar residues and results in a viscous, sticky secretion

Question 16

Describe cells of the serous acini.

Answer 16

Cells are typically wedge shaped and have a prominent nucleus in the basal part of the cell. They have extensive rough endoplasmic reticulum and a granular appearance due to large numbers of apical secretory vesicles

Question 17

Describe cells of the mucous acini

Answer 17

Mucous cells tend to be found in the tubular element of the tubulo-acinar glandular structure. The cells have large numbers of prominent secretory granules packing the cytoplasm. When the tissue is processed using routine methods, these granules are large and compress the nucleus toward the basal part of the cell

Question 18

what is serous demilune?

Answer 18

In salivary glands with mixed acini the serous cells in routine preparations often appear as a crescent shaped collection of cells at the end of the secretory unit

Question 19

How are secretions expelled from the gland?

Answer 19

Myoepithelial cells - population of epithelial cells that have become specialized for contraction. These cells form a network around the groups of secretory cells and when they contract, help to expel the secretions from the gland

Question 20

what is the duct system of major salivary glands?

Answer 20

• The acinus empties into an intercalated duct, consisting of cuboidal cells
• The intercalated duct empties into a striated duct
• striated ducts empty into excretory ducts (collecting ducts)
• the excretory merge and the duct becomes larger and near the opening of the oral cavity the lining of the duct becomes stratified squamous epithelium

Question 21

Put the glands in order of higher serous:mucous ratio of cells to lowest

Answer 21

parotid- submandibular - subligual

Question 22

where are minor salivary glands found?

Answer 22

Minor salivary glands are found scattered throughout the oral mucosa, although they are absent from the gingiva and the anterior part of the hard palate

Question 23

Describe minor salivary glands.

Answer 23

They are predominately mucous in form and exhibit a continuous, slow secretory activity. They account for about 10% of salivary volume

Question 24

Give some examples of minor salivary glands

Answer 24

• Minor sublingual glands found associated with the lower surface of the tongue.
• Labial glands on the inner surface of the lips.
• Palatine glands in the submucosa of the soft and posterior hard palate

Question 25

Describe taste buds.

Answer 25

These multicellular chemoreceptive units span the epithelium and are about 50µm in diameter. They include taste cells (sensory cells), support cells and basal cells. Molecules enter the pore and then interact with receptors on microvilli on the sensory cells. The cells lack axons, but release neurotransmitter to stimulate afferent nerve fibres

Question 26

Describe the innervation of the salivary glands

Answer 26

Receive both parasympathetic (transmitter: acetylcholine) and sympathetic (transmitter: noradrenalin) innervation

Question 27

what effects do parasympathetic and sympathetic innervation have in salivary glands ?

Answer 27

Parasympathetic activation is thought to increase fluid release while sympathetic increases release of preformed elements