Saliva Flashcards
Where is the parotid gland located
Anterior to the ear, posterior to ramus, inferior to zygomatic arch. Extends from zygomatic arch to angle of mandible
Where is submandibular gland located
Inferior and posterior to body of mandible at submandibular fossa. Superficial and deep part wedged by mylohyoid
Where is sublingual gland located
Sublingual fossa below mucous membrane next to mandibular canines. Superior to mylohyoid. Anterior to submandibular gland
What is the duct for parotid gland
Stenson’s duct. Runs across masseter and pierces buccinator and mucous membrane of cheek to open opposite 2nd molar
What is the duct for submandibular gland
Wharton’s. Long tortuous route along floor of mouth then against gravity to open into oral cavity at sublingual papillae
What is the duct for sublingual gland
Bartholin’s which opens directly into submandibular duct to drain into sublingual papilla. Ducts of rivinius which are multiple small ducts which open into sublingual fold (extends from sublingual caruncle to posterolateral part of gum
Describe minor salivary glands
Located within submucosa with short ducts that open directly onto mucosal surface. Located at oral mucosa except gingiva and anterior palate. Mostly mucous glands, major source of secretory iga. Only von ebners glands located below sulci of circumvallate papillae is serous producing
Describe the saliva produced by the cells that are poorly stained with an empty appearance
Mucous acini. Mucin appear unstained. Mucous saliva is carbohydrate rich, viscous, mucin rich, for lubrication to help with swallowing
Describe the saliva from strongly stained cells that are pyramidal in shape with thin basement membrane and narrow apex bordering lumen of acini
Serous mucous. Protein rich, rich in amylase, watery secretion to help with digestion
What are the crescent shaped serous cells in mucous acini called
Serous semilunes
Who do myoepithelial cells do
Contractile cells associated with secretory end pieces and intercalated ducts help to expel saliva from acini into the ducts
What are the 2 stages of saliva production
Stage 1: isotonic saliva produced from secretory acini containing water, electrolytes, mucin and proteins
Stage 2: primary saliva passes through duct system, selective reabsorption of Na+ and Cl- and some K+ and HCO3- secreted leading to hypotonic saliva being secreted from excretory duct. Lumen not completely permeable to water
How does smelling food make you salivate
Chemo/mechanoreceptors activate parasympathetic receptors, releasing acetylcholine that activates muscarinic receptors. Secretion of watery saliva (rich with digestive enzyme amylase) increases
How does stress give you dry mouth
Activate sympathetic neurons, release of norepinephrine, activing b adrenergic receptors resulting in release of small volumes of viscous saliva
Innervation of parotid gland
Inferior salivatory nucleus at medulla oblongata, form glossopharyngeal nerve which branches into tympanic branch enter tympanic plexus form lesser petrosal nerve, form otic ganglion, auriculotemporal branch of trigeminal nerve innervates parotid gland
Sympathetic from superior cervical ganglion, fibres travel via external carotid artery
Innervation of submandibular and sublingual glands
Superior salivatory nucleus at pons, form facial nerve branches into chorda tympani travels within/hitchhike in lingual nerve, go to submandibular ganglion and innervates glands
Sympathetic from superior cervical ganglion, fibres travel via external carotid artery
Innervation of minor palatal salivary glands
Superior salivatory nucleus at pons, form facial nerve which branches into greater petrosal nerve, becomes vidian nerve travelling through pterygoid canal, enter pterygopalatine ganglion, maxillary division of trigeminal nerve innervates glands
Do cholinergic/muscarinic drugs eg. Pilocarpine increase or decrease salivation
Increase
What is the function of mucin in saliva
Lubricate as negatively charged mucin can form expanded structure
Hydration as negatively charged mucin can bind water
Pellicle formation as negatively charged mucin can bind hydroxyapatite and ca2+ preventing it from being lost
Remove bacteria because mucin can help with agglutination of bacteria, forming a bolus that can be rinsed out. Also helps to disperse bacterio via glycan specific interactions to suppress biofilm formation
Why do babies drool so much
Teeth. Underdeveloped/weak perioral muscles for swallowing saliva. Produce excessive amount of saliva for various reasons eg underdeveloped digestive system
What do salivary proteins do
Help to form the salivary pellicle. Help to module microbial colonisation in oral cavity by interacting with dental and mucosal surfaces
Function of slatherins and proline rich proteins
Prevent precipitation of super saturated calcium phosphate. This is done via binding to hydroxyapatite and calcium, maintaining integrity of the tooth surface
How is digestive function of saliva carried out. Use 2 specific enzymes for examples
Salivary a amylase which breaks down starch to simpler sugars by cleaving a 1,4 glycosidic bond.
Lingual lipase secreted primarily by von ebner glands which hydrolyse triglycerides into free fatty acids and partial glycerides
Why is lingual lipase important in newborn infants
Pancreatic lipase need more time to develop
