Anatomy Of Salivation And Swallowing

Question 1

What are the functions of saliva?

Answer 1

Lubrication
Maintains oral hygiene
Early stages of digestion
Protection from infection (innnate immunity)
Taste
Pathologically transmitting infection

Question 2

What type of glands are salivary glands?

Answer 2

Exocrine glands

Question 3

What is an exocrine gland?

Answer 3

Gland secreting its secretions into ducts

Question 4

What is contained in saliva?

Answer 4

K+ and Bicarbonate (typically alkaline)

Mucins
Amylase
Lingual Lipase
Immune proteins

Question 5

What type of molecule is mucin and what is its role?

Answer 5

Glycoprotein

Helps with lubrication

Question 6

What gland secretes amylase?

What’s its role?

Answer 6

Salivary gland

Breaks down starch into sugars

Question 7

What are some immune proteins found in saliva?

Answer 7

IgA
Lysozymes
Lactoferrin

Question 8

What is the function of lactoferrin in the saliva?

Answer 8

It sequesters iron preventing bacteria using it for growth (e.coli)

Question 9

What is the function of lysozymes?

Answer 9

Antimicrobrial (innate immunity)

Question 10

What is Xerostomia?

Answer 10

Dry mouth due to no saliva production

Question 11

What are some complications that can occur as a result of Xerostomia?

Answer 11

Poor nutrition (less amylase)
Infections in mouth (gingivitis, oral thrush)
Tooth decay, gum disease (acidic conditions not neutralised by alkaline saliva)
Halitosis
Poor sense of taste

Question 12

What are the 2 types of gum in the mouth?

Answer 12

Lingual surface of gum

Buccal surface of gum

Question 13

What is the lingual surface of gum?

Answer 13

The surface of the gum in contact with the tongue (so on the inside)

Question 14

What is the Buccal surface of gum?

Answer 14

Surface of gum in contact with the cheek (outside)

Question 15

What are deciduous teeth?

Answer 15

The milk teeth in children that will fall out

Question 16

What is the biggest salivary gland?

Answer 16

Parotid gland (meaning near the ear gland)

Question 17

How does the parotid duct travel?

Answer 17

It penetrates the Buccinator muscle draining into the oral cavity around the 2nd upper molar tooth

Question 18

Where are the sublingual salivary glands located?

Answer 18

Above the floor of the mouth

Question 19

What 2 salivary glands ducts are found on the floor of the mouth?

Answer 19

Submandibular salivary glands duct (seen the gland in DR)

Sublingual salivary gland

Question 20

How are salivary secretions regulated?

Answer 20

Autonomic nervous system (neural)

Question 21

What part of the autonomic nervous system is the main DRIVER of salivary secretion?

Answer 21

Parasympathetic nervous system

Question 22

How does the sympathetic nervous system affects salivary production?

How does it do this?

Answer 22

Reduces salivary production

Vasoconstriction of blood vessels supplying salivary glands

Question 23

What is an example of a drug that can cause a dry mouth as a side effect?

Answer 23

Atropine

Question 24

What viral infection can infect the parotid gland leading to its inflammation and can also cause meningitis, testicular swelling, ovarian swelling?

Answer 24

MUMPs

Question 25

Why is an inflamed parotid gland very painful?

Answer 25

The surrounding capsule is very tight so isn’t much room for expansion

Question 26

What is parotid sialography?

Answer 26

Imaging of the parotid salivary gland

Question 27

What is parotid sialography useful to see?

Answer 27

If a stone (calculus) or tumour is blocking the salivary flow

Question 28

What does the prefix sialo- mean?

Answer 28

Salivary gland

Question 29

What is a bolus?

Answer 29

Food that’s been chewed in the mouth and is ready to be swallowed

Question 30

How do the lungs sit in relation to the oesophagus?

Answer 30

Lungs sit anteriorly to the oesophagus

Question 31

What are the 3 phases to swallowing?

Answer 31

Oral preparatory phase Pharyngeal phase Oesophageal phase

Question 32

What is the pharynx?

Answer 32

Muscular tube connecting the mouth to the oesophagus

Question 33

State whether each of the 3 phases of swallowing is voluntary or involuntary?

Answer 33

Oral prepatory phase = Voluntary Pharyngeal phase = involuntary Oesophageal phase = involuntary

Question 34

What occurs in the oral preparatory phase of swallowing?

Answer 34

Bolus pushed to back of mouth Once it touches the pharyngeal wall the pharyngeal phase begins (swallow reflex starts)

Question 35

What occurs during the Pharyngeal phase of swallowing?

Answer 35

Soft palate lifts up sealing nasopharynx (stops bolus entering nasal cavity) Pharyngeal constrictors push bolus downwards (peristaltic) Larynx elevates, epiglottis closes sealing trachea Vocal cords Adduction help protect the air way Upper oesophageal sphincter opens allowing bolus down

Question 36

What is the epiglottis?

Answer 36

Elastic cartilage flap that’s closes protecting the airway/trachea

Question 37

What are the vocal cords?

Answer 37

2 flaps of mucosa that are open when talking

Question 38

What occurs during the Oesophageal phase of swallowing?

Answer 38

Upper oesophageal sphincter closes Peristaltic wave carries bolus down into oesophagus

Question 39

What are the pharyngeal constrictors?

Answer 39

Muscles at the top of the oesophagus

Question 40

What are the sensory receptors in the swallow and gag reflex? Where are they located?

Answer 40

Mechnoreceptors In pharynx at back of throat

Question 41

What nerve transmits the sensory input fro the mechanoreceptors in the back of the pharynx in the swallow/gag reflex?

Answer 41

Glossopharyngeal nerve = Cranial nerve IX

Question 42

What part of the brain does the Glossopharyngeal nerve (Cranial nerve IX) transmit impulse from mechanoreceptors in the swallow/gag reflex?

Answer 42

Medulla

Question 43

Once the information has been processed by the medulla in the swallow/gag reflex, what motor neurone transmits the impulse?

Answer 43

Vagus nerve (Cranial nerve X)

Question 44

What muscles does the Vagus nerve (Cranial Nerve X) transmit impulses to in the swallow/gag reflex? What do these muscles do?

Answer 44

Pharyngeal constrictors Pushes bolus down to oesophagus

Question 45

What is the swallow/gag reflex pathway from sensory neurone all the way to the motor response?

Answer 45

Mechnoreceptors in pharynx -> Glossopharyngeal nerve (IX) -> medulla -> Vagus nerve (X) -> pharyngeal constrictors

Question 46

What determines whether the gag reflex or swallow reflex will be triggered if they are the same pathway?

Answer 46

Context Age of individual (children under 3months will gag all food up)

Question 47

What is Dysphagia?

Answer 47

Difficulty swallowing

Question 48

Why may you be concerned about a patients swallowing whos had a stroke?

Answer 48

Stroke causes muscle weakness so muscles of pharynx can be weakened leading to poor coordination

Question 49

How May oesophageal tumours affect swallowing?

Answer 49

Dysphagia Make it harder to swallow solid boli

Question 50

How does the oesophagus run through the body?

Answer 50

Runs from neck, through thoracic cavity into abdomen Runs through posterior mediastinum posteriorly to the heart

Question 51

What imaging technique of the heart can be done thanks to the oesophagus running through the posterior mediastinum posteriorly to the Heart?

Answer 51

Transoesophageal echocardiogram

Question 52

What are the 4 narrowings of the oesophagus from most superior to inferior?

Answer 52

Junction of oesophagus with pharynx Where aortic arch crosses oesophagus Where oesophagus compressed by left main bronchus At oesophageal hiatus where the oesophagus penetrates the diaphragm

Question 53

What are the 4 narrowings of the oesophagus from most superior to inferior?

Answer 53

Junction of oesophagus with pharynx Where aortic arch crosses oesophagus Where oesophagus compressed by left main bronchus At oesophageal hiatus where the oesophagus penetrates the diaphragm

Question 54

What condition does continual gastro-oesophageal reflux cause in the lower oesophagus?

Answer 54

Metaplastic changes called Barrett’s Oesophagus

Question 55

What helps prevent Gastro-oesophageal reflux?

Answer 55

Lower oesophgeal sphincter in distal oesophagus Narrowing where oesophagus crosses diaphragm Intrabdominal oesophagus gets compressed when abdominal pressure rises Mucosal rosette at cardia Acute angle of entry of oesophagus creates a flap which closes when pressure in stomach increases

Question 56

What are the Mucosal rosette at the cardia?

Answer 56

Puckered mucosae that increase SA helping maintain the closure of the lower oesophageal sphincter