Physiology of thr mouth and oesophagus Flashcards
What are the three types of salivary glands
parotid, submandibular and sublingual
what does saliva contain?
- mucous to help lubricate food
- alpha-amylase to initiate breakdown of carbohydrate (beginning of digestion)
- lysozyme (antibacterial actions)
how is saliva formed?
isotonic fluid is produced by acinar cells which secrete electrolytes and water
The fluid is modified as it flow along salivary duct (autonomic NS)
Final composition depends upon flow rate and neuronal input
what are acinar cells in saliva important ?
for transportation of ions
how is salivary secretion regulated by parasympathetic signals?
when you are about to eat
-watery saliva
- rich in amylase and mucous
- increased blood flow to glands
how is salivary secretions regulated by sympathetic signals?
causes the mouth to feel dry
- promotes increased output of thicker mucous
- reduces blood flow to glands
- overall effects a reduction in secretion of watery saliva
what is the voluntary stage of swallowing (deglutition)?
tongue pushes back bolus to orthopharnyx
what happens during the pharyngeal stage?
controlled by deglutition centre in medulla and pons of the brain
-The soft palate and uvula move up to seal off the nasopharynx (link to nose)
-The larynx is raised and the glottis is sealed
-the epiglottis covers the glottis and breathing is suspended for 1-2 seconds to allow food to move down the oesophagus and not the trachea
What muscles are in each third of the oesophagus?
First - muscularis layer is striated(skeletal) to assist in swallowing
Middle - mixture of striated and smooth
Last - all smooth
What are side effects, treatment and causes of dry mouth (xerostomia)
Can lead to mouth ulcers and can effect both digestion and drug absorption
Can be a side effect of certain drugs and can be treated with artificial saliva
what can be used to treat mouth ulcers ?
usually clear up themselves but in some cases require anti inflammatory (corticosteroid) and anti microbial mouthwash to prevent infection
what is oral thrush; what causes it and what treatment is there?
A yeast infection
Caused by ; over use of antibiotics, poor immune system, underlying disease, smoking
Treatment aimed at reducing fungal infection using oral anti fungal gel eg miconazole
what are examples of medications that can cause tooth decay
Antacids - may contain sugar (chewable antacids can get stuck in teeth)
Pain medications - opioids can cause dry mouth and erosion of tooth enamel
Anti-histamines - can block the release of saliva, resulting in dry mouth
Inhalers contains beta-adrenergic agonist, this is slightly acidic and this can be harmful to tooth enamel causing susceptibility to tooth decay
