Salivation Swallowing

Question 1

What is the composition of saliva ?

Answer 1

Water (hypotonic)
Potassium and bicarbonate 
Mucins (glycoprotein for lubrication )
Amylase 
Lingual lipase
Immune proteins (lysozyme, IgA)

Question 2

Which gland secrete lipase in the saliva ?

Answer 2

Lingual glands

Question 3

What is the function of lysozyme in the saliva ?

Answer 3

Destroy microorganism, immune protection

Question 4

What is the condition of dry mouth called and what consequence can it have ?

Answer 4

Xerostomia

Dysphagia 
Oral candidiasis (thrush)
Ulcers
Dental cavities 
...

Question 5

Describe the basic topography of the salivary glands

Answer 5

Parotid glands : lateral Ramus of mandible , duct runs medially to masseter through buccinator

Sublingual glands : Above the floor of mouth , multiple ducts laterally

Submandibular glands : underneath floor of mouth with a superficial lobe going above , one duct open medially under tongue

Question 6

Which muscle forms the floor of the mouth ?

Answer 6

Mylohyoid

Question 7

How are the salivary gland controlled ?

Answer 7

Parasympathetic innervation :

Parotid : Glossopharyngeal nerve ( CN IX)

Submandibular and Sublingual : Parasympathetic fibres of the Facial nerve CN V

Question 8

Which drugs would have dry mouth as a side effect ?

Answer 8

Anti muscarinic drugs

Question 9

Which disease commonly cause swelling of the parotid glands ? Which other symptoms are seen ?

Answer 9

Mumps

Inflammation of parotid gland, ovaries , testicles, encephalitis

Question 10

Why is swelling of the parotid gland so painful ?

Answer 10

Covered by fibrous capsule , can’t expand

Question 11

Which test is used to see stone in parotid duct ?

Answer 11

Sialography

Question 12

What are the 3 stages of swallowing ?

Answer 12

Oral preparatory phase
Pharyngeal phase
Oesophageal phase

Question 13

What happens in the first phase of swallowing ? How is the control ?

Answer 13

Bolus pushed towards pharynx by tongue

Voluntary

Question 14

What happens in the second phase of swallowing ? How is the control ?

Answer 14

• Soft palate seals off nasopharynx
• Pharyngeal constrictors push bolus down
• Larynx elevates, epiglottis close to over airway and vocal cords adduct
• Opening of Upper OS

Involuntary

Question 15

What happens to the breathing function during swallowing ?

Answer 15

Temporarily ceases

Question 16

How does the larynx elevates during swallowing ?

Answer 16

Pulled by supra hyoid muscles due to movement of hyoid bone

Question 17

What happens in phase 3 of swallowing ?

Answer 17

Closure of UOS

Peristalsis move bolus down oesophagus

Question 18

Why can babies breath and drink at same time ?

Answer 18

Epiglottis projects up in nasopharynx ,in contact with uvula > milk is diverted laterally to oesophagus whilst air goes down pharynx

Question 19

What development enables speech ?

Answer 19

Neck elongation ,pulling down epiglottis allowing sound formation from the larynx to go to oral cavity

Question 20

How is swallowing controlled ?

Answer 20

Mechanoreceptors at back of throat detect bolus>Glossopharyngeal nerve CN IX > Medulla > Motor response via Vagus nerve > Pharyngeal constrictors

Question 21

Why do baby have more pronounced gag reflex?

Answer 21

Adults only Glossopharyngeal stimulation causes gag reflex , in babies , stimulation of more anterior structures do too

Question 22

How might a stroke affecting the muscles of the face affect swallowing?

Answer 22

Area of brain supplying the facial muscles near the area supplying the pharyngeal constrictors

Question 23

What can be the symptoms of an oesophageal tumour ?

Answer 23

Feeling off food sticking

Dysphagia

Question 24

Describe the anatomical location and relations of the oesophagus

Answer 24

Posterior mediastinum

Posterior to trachea and larynx ,at the right of aorta

Question 25

At which level is the oesophagus going through diaphragm ?

Answer 25

T10

Question 26

What are the points of oesophageal narrowing ?

Answer 26

• At junction with pharynx
• Where it’s crossed by arch of aorta
• Where it’s compressed by the left main bronchus
• At the oesophageal hiatus in diaphragm

Question 27

What are the five anatomical mechanisms preventing reflux?

Answer 27

• LOS : functional sphincter formed by thickening off smooth muscle
• Diaphragm
• Intra-abdominal oesophagus part gets compressed when intra abdominal pressure rises
• Mucosal rosette at cardia
• Acute angle of entry in stomach