Swallowing and Saliva

Question 1

what is the composition of saliva

Answer 1

water, bicarbonate, mucins, amylase, lingual lipase, immune proteins

Question 2

what are the functions of salvia

Answer 2

lubricate food and mouth 
protect against bacteria 
oral hygiene 
carry taste molecules to taste buds
allow transmission of infection 
chemical digestion

Question 3

what is Xerostomia

Answer 3

where you have a dry mouth so very little saliva

Question 4

what effects can a dry mouth cause

Answer 4

ulcers
difficultly swallowing
oral candidiasis

Question 5

what drugs could cause dry mouth

Answer 5

drugs that inhibit muscarinic Ach receptors

Question 6

why is swelling of the parotid gland so painful and when can this happen

Answer 6

as the gland has a thick fibrous capsule surrounding it which can’t expand - it can happen during mumps

Question 7

what are the 3 salivary glands called

Answer 7

parotid, submandibular, sublingual

Question 8

what nerve supplies the parotid gland

Answer 8

glossopharyngeal nerve

Question 9

which cranial nerve is the glossopharyngeal nerve

Answer 9

9th

Question 10

what nerve supplies the submandibular and sublingual glands

Answer 10

facial nerve

Question 11

is salivation activated by the sympathetic NS or parasympathetic NS

Answer 11

parasympathetic

Question 12

what happens in the oral preparatory phase of swallowing

Answer 12

it is voluntary and pushes the bolus of food is pushed to the back of the pharynx

Question 13

what happens in the pharyngeal phase of swallowing

Answer 13

• 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

Question 14

what happens the oesophageal stage of swallowing

Answer 14

the upper oesophageal sphincter closes and peristalsis begins

Question 15

what type of muscle is the oesophagus made up of

Answer 15

skeletal muscle at the top

smooth muscle at the bottom

Question 16

at what level does the oesophagus pierce the diaphragm

Answer 16

T10

Question 17

where are the 4 narrowings of the oesophagus

Answer 17

at the junction with the pharynx
where the arch of the aorta crosses
where the main left bronchus branch crosses
before piercing the diaphragm

Question 18

what can repeated acid reflux cause

Answer 18

Barrett’s oesophagus

Question 19

what contributes to make the lower oesophageal sphincter

Answer 19

the smooth muscle of the oesophagus
pinching in of the oesophagus by the diaphragm
rossette folding of mucosa
oblique angle

Question 20

why can a stroke cause dysphasia

Answer 20

as the area of the brain controlling swallowing is close to the area controlling the face which is affected in a stroke

Question 21

how can oesophageal tumours cause dysphasia

Answer 21

as the tumours impinge on the lumen so food can feel as though its stuck

Question 22

describe the gag reflex

Answer 22

• bolus detected by mechanoreceptors on the pharynx wall
• sends signals to the medulla via the glossopharyngeal nerve
• activates pharyngeal constrictors via the vagus nerve