Anatomy of salivation and swallowing Flashcards
What is in saliva?
Mostly water Potassium Bicarbonate (makes saliva slightly alkaline -pH8) It is hypotonic Mucins - lubrication Amylase Lingual lipase Immune proteins
What are the functions of saliva?
Lubrication of oral cavity Form a bolus and soften dry foods Secrete lysosomes Keeps teeth clean and white Digestion Solvent Spread infections
What is Xerostomia?
Dry mouth
What are the consequence of Xerostomia?
Dental issues
Inflamed tongue
Dehydration
What are the salivary glands?
Parotid glands
Sublingual glands
Submandibular gland
What is the main way salivary glands are regulated?
They are primarily driven by the autonomic nervous system.
Parasympathetic is main driver for salivary production.
Sympathetic also stimulates secretion of small amounts of saliva, but also causes vasoconstriction.
What nerve innervates the parotid gland?
Glossopharyneal nerve
What nerve innervates the sublingual and submandibular glands?
Facial nerve
Why is parotiditis so painful?
Because the parotid gland is ensheathed by a capsule that does not swell.
Mumphs can cause this.
The parotid sheath is innervated by the trigeminal nerve whereas the parotid gland is innervated by the glossopharyngeal nerve.
What is a sialograph?
Inject dye to see salivary glands.
What happens during the oral preparatory phase of swallowing?
Voluntary
Pushes bolus towards pharynx
Once bolus touches pharyngeal wall, pharyngeal phase begins.
What happens during the pharyngeal phase of swallowing?
Involuntary
Soft palate seals off nasopharynx
Pharyngeal constrictors push bolus downwards.
Larynx elevates, closing epiglottis
Vocal cord adducts (projecting airway) and breathing temporarily cases
Opening of the upper oesophageal sphincter
What happens during the oesophageal phase of swallowing?
Involuntary
Closure of the upper oesophageal sphincter
Peristaltic wave carries bolus downwards into oesophagus
How do babies swallow safely?
Epiglottis projects against nasopharynx which means the baby has separated the airway and the foodway. This means the food / drink goes around epiglottis and into the foodway.
BUT, it means you cannot speak because the epiglottis is in the pharynx.
What is the neural control of swallowing?
Mechanoreceptors in pharyngeal wall
Glossopharyngeal nerve
Medulla
Vagus nerve
Pharyngeal constrictor to push bolus down
The gas reflex has the same neural control as this
