Salivation And Swallowing

Question 1

What is the composition of saliva?

Answer 1

Mostly water
Hypertonic in general (cf blood)
Rise in K+ and bicarbonate so pH generally a bit alkali 8, can be a hit acidic though
Mic ins to lunricating
Amylase, lingual lipase
Immune proteins (IgA, lysozyme and lactoferrin)

Question 2

What are the functions of saliva?

Answer 2

Lubricate mouth 
Lubricate food 
Transmit diseases 
Immunity 
Starts chemical digestion 
Surface tension holds dentures in place 
Solvent

Question 3

What might a patient with a dry mouth complain of?

Answer 3

Dry mouth 
Dentures falling out 
Bad breath 
Oral infections 
Ulcers 
Problems swallowing 
Dental cavities

Question 4

Name 3 salivary glands

Answer 4

Parotid gland
Sublingual gland
Submandibular

Question 5

Where does the parotid duct penetrate into the oral cavity?

Answer 5

Penetrates bucinator opposite the 2nd upper molar

Question 6

The sublingual duct enters ….. on the floor of the mouth (lots of openings) and the submandibular duct enters ….. on the floor of the mouth

Answer 6

Laterally

Medically

Question 7

The submandibular gland is what shape and where would you palpate it?

Answer 7

Pacman

Under the mandible

Question 8

What drug class may have xerostomia as a side effect and why?

Answer 8

Antimuscarinics
Parasympathetic is the main driver for increase salivary productions
Note sympathetic has a small stimulators effect but also causes vasoconstriction so lessens production

Question 9

The facial nerve supplies which salivary glands?

Answer 9

Submandibular and sublingual

Question 10

Which nerve innervates the parotid?

Answer 10

Glossopharyngeal

Question 11

The Submandibular gland is C shaped around what structure and name its two anatomical subdivisions?

Answer 11

Mylahyoid

Superficial (most caudal- palatable bit) and Deep

Question 12

What broad drug class may cause dry mouth symptoms?

Answer 12

Antimuscarinics

Question 13

What gets inflamed in mumps?

Answer 13

Parotid glands (chipmunk face)
Ovary and testes - v painful for boys

Question 14

What is mumps encephalopathy?

Answer 14

Mumps in the cerebellum

Question 15

Why is a parroted gland inflammation sore?

Answer 15

Fibrous capsule around the gland is not stretchy so the pressure with in increases

Question 16

What does the prefix sialo- mean?

Answer 16

Salivary

Question 17

Outline the oral phase of swallowing.

Answer 17

The oral phase is under voluntary control and involves using the muscles in the oral cavity to push a bolus of food posteriorly to the pharynx.

Question 18

What marks the start of the pharyngeal phase of swallowing?

Answer 18

Bolus touches pharyngeal walls

Question 19

Which phases of the swallow are involuntary?

Answer 19

Pharyngeal and oesophageal

Question 20

What happens in the pharyngeal phase?

Answer 20

Soft palate seals off the nasopharynx. (food won’t flow up through the nose)
Pharyngeal constricters push bolus down.
Laryngeal elevation from supra hyoid action. This closes the epiglottis (food won’t go down the wrong pipe)
Vocal cords adduct and breathing temporarily stops (again food won’t enter the lungs)
Upper oesophageal sphincter opens

Question 21

How does food move down the oesophagus?

Answer 21

The oesophageal phase of swallowing is involuntary. The upper oesophageal sphincter closes (food won’t go back up)
Peristaltic contractions move bolus down to stomach

Question 22

What plane is the nasal cavity in?

Answer 22

Horizontal

Question 23

Why can babies breath and suckle simultaneously with out everything going the wrong way?

Answer 23

Epiglottis in babies projects up into nasopharynx

Question 24

With growth of the neck the epiglottis descends and elongates, why is this important?

Answer 24

Allows speech as well as lung/oesophageal communication

Question 25

Outline the neural control of swallowing

Answer 25

Mechanoreceptors at the back of the throat will detect bolus.
The glossopharyngeal nerve will signal to the medulla that we need to swallow.
In the medulla the glossopharyngeal and vagus nerve synapse.
Vagus nerve carries motor innervation to the pharyngeal sphincter.

Question 26

What controls whether we swallow or gag?

Answer 26

Its the same reflex arc so the input for why we would do one or another is psychological

Question 27

What is the term given to difficulty swallowing?

Answer 27

Dysphagia

Question 28

List causes of dysphagia.

Answer 28

Stroke
Oesophageal tumour
atresia

Question 29

Where does the oesophagus natrually have narrowing and why?

Answer 29

The oesophagus is posterior to the trachea so 4 major narrowings.

1. Pharynx and Oesophagus Junction
2. Where the aorta crosses the oeophagus
3. Left main bronchus compression
4. Oesophageal Hiatus T10

Question 30

Where is skeletal muscle seen in the oesophagus?

Answer 30

Right at the top- then its smooth all the way down

Question 31

How do we prevent reflux?

Answer 31

Smooth muscle at the distal need of the oesophagus forms a functional sphincter as well as the diaphragm pinching the oesophagus to stop back flow. If abdominal pressure increases the intraabdominal oesophagus will be compressed. Mucous rosette at cardia and the acute angle of oesophageal entrance all help to combat reflux.