Swallowing and Saliva Flashcards
what is the composition of saliva
water, bicarbonate, mucins, amylase, lingual lipase, immune proteins
what are the functions of salvia
lubricate food and mouth protect against bacteria oral hygiene carry taste molecules to taste buds allow transmission of infection chemical digestion
what is Xerostomia
where you have a dry mouth so very little saliva
what effects can a dry mouth cause
ulcers
difficultly swallowing
oral candidiasis
what drugs could cause dry mouth
drugs that inhibit muscarinic Ach receptors
why is swelling of the parotid gland so painful and when can this happen
as the gland has a thick fibrous capsule surrounding it which can’t expand - it can happen during mumps
what are the 3 salivary glands called
parotid, submandibular, sublingual
what nerve supplies the parotid gland
glossopharyngeal nerve
which cranial nerve is the glossopharyngeal nerve
9th
what nerve supplies the submandibular and sublingual glands
facial nerve
is salivation activated by the sympathetic NS or parasympathetic NS
parasympathetic
what happens in the oral preparatory phase of swallowing
it is voluntary and pushes the bolus of food is pushed to the back of the pharynx
what happens in the pharyngeal phase of swallowing
- the nasopharynx is sealed off by the soft palate
- the trachea is sealed off by the closing of the vocal cords and by the larynx elevating to close the epiglottis
- the 3 pharyngeal constrictor muscles contract to push blue downwards
what happens the oesophageal stage of swallowing
the upper oesophageal sphincter closes and peristalsis begins
what type of muscle is the oesophagus made up of
skeletal muscle at the top
smooth muscle at the bottom
at what level does the oesophagus pierce the diaphragm
T10
where are the 4 narrowings of the oesophagus
at the junction with the pharynx
where the arch of the aorta crosses
where the main left bronchus branch crosses
before piercing the diaphragm
what can repeated acid reflux cause
Barrett’s oesophagus
what contributes to make the lower oesophageal sphincter
the smooth muscle of the oesophagus
pinching in of the oesophagus by the diaphragm
rossette folding of mucosa
oblique angle
why can a stroke cause dysphasia
as the area of the brain controlling swallowing is close to the area controlling the face which is affected in a stroke
how can oesophageal tumours cause dysphasia
as the tumours impinge on the lumen so food can feel as though its stuck
describe the gag reflex
- bolus detected by mechanoreceptors on the pharynx wall
- sends signals to the medulla via the glossopharyngeal nerve
- activates pharyngeal constrictors via the vagus nerve
