Function of the mouth/oesophagus and associated diseases

Question 1

what is the function of the mouth and oropharynx?

Answer 1

Mastication

Chewing food increasing the surface area for digestion

Question 2

What structures are important in the mouth and why?

Answer 2

Teeth - mastication to increases the surface area of the food
Tongue - sensory organ and use in swallowing
Saliva - initiation of carbohydrate and fat metabolism via salivary amylase and lipases.

Question 3

What is digestion?

Answer 3

The process by which dietary nutrients are converted into a form that the small intestine can absorb.

Question 4

What are the different salivary glands?

Answer 4

Parotid gland - water secretion (serous)
Submandibular gland - viscous secretion (produces a mixed type secretion.
Sublingual gland - mucous rich secretion

Question 5

What are salivary glands?

Answer 5

exocrine glands that secrete amylase and lipase.

secretory organs that secrete mucous IgA, lysozymes and lactoferrin

Question 6

What are acinar cells?

Answer 6

Cells that make proteins and therefore enzymes which then releases the enzymes into the mouth via ductal cells

Question 7

What are ductal cells?

Answer 7

Produces mucous (goblet cells) that modify the saliva, secrete water and electrolytes

Question 8

What is the % secretion from each of the salivary glands?

Answer 8

Parotid - 20%
Submandibular - 70%
Sublingual - 10%

Total volume secreted per day is 1.5 litres

Question 9

What is the function of salivar?

Answer 9

Lubrication
Hydration - keeps the oral mucosa moist and prevents dehydration and cell death
Cytoprotection - protects oral and oesophageal mucosa from damage

Question 10

What is the immune function of saliva secretions?

Answer 10

IgA antibodies bind to pathogenic antigens
Lactoferrin binds to iron and is a bactericidal
Lysozymes attack bacterial cell walls

Question 11

What is the function of the salivary duct?

Answer 11

modify the secretion of acinar cells by extracting the Na and Cl ions and secreting K and HCO3 ions. this means that saliva is hypotonic and alkaline

Question 12

what is the importance of saliva being alkaline?

Answer 12

protects teeth from bacterial acid

neutralises gastric acid that refluxes into the oesophagus

Question 13

What are some salivary gland diseases?

Answer 13

Sjogrens syndrome - autoimmune attack of salivary and tear glands which results in dry mouth and eyes
Mumps virus - prodrome of headache and fever

Question 14

How are secretions of salivary glands controlled?

Answer 14

Autonomic nervous system via the parasympathetic system - Facial nerve and glossopharyngeal nerve

Question 15

what is the oral preparatory phase of swallowing?

Answer 15

Food is manipulated in the mouth and masticated to reduce to a consistency which can be swallowed

Question 16

What is the oral phase of swallowing?

Answer 16

tongue propels food posteriorly until the pharyngeal swallow is triggered

Question 17

What is the pharyngeal phase of swallowing?

Answer 17

the bolus is transported through the pharynx with coordinated closure of the glottis via movement of the epiglottis and cessation of breathing and relaxation of the upper oesophageal sphincter (UOS)

Question 18

what is the oesophageal phase of swallowing?

Answer 18

Oesophageal peristalsis carries the bolus from the UOS through the oesophagus to the lower oesophageal sphincter

Question 19

What is the type of muscle in the oesophagus?

Answer 19

Striated and smooth muscle

Question 20

What is the oesophagus?

Answer 20

Complex organ that starts in the thorax and ends up in the abdomen.

Question 21

What is the oesophageal hiatus?

Answer 21

the hole in the diaphragm through which the oesophagus and vagus nerve pass

Question 22

What is Gastro oesophageal reflux disease (GORD)?

Answer 22

Chronic repeated reflux episodes of gastric juice back up through the gastro-oesophageal sphincter into the oesophagus

Question 23

What causes GORD?

Answer 23

Hiatus hernia - sliding or rolling hernias
Obesity
pregnancy
Drugs that lower tone at the LOS
Zollinger Ellison Syndrom

Question 24

What is the function of the lower oesophageal sphincter?

Answer 24

Prevents reflux of stomach acid into the oesophagus

Question 25

What are the symptoms of GORD?

Answer 25

Heartburn
regurgitation
Dysphagia - due to inflammation or stricture
Cough ,Hoarsness, Chronic earache - laryngopharyngeal reflux

Symptoms correlate poorly with actual oesophagitis

Question 26

What are some outcomes of GORD?

Answer 26

Oesophagitis
stricture
Barrett’s metaplasia
Oesophageal adenocarcinoma

Question 27

How can GORD be diagnosed?

Answer 27

Suprassed by endoscopy

24hr pH monitoring

Question 28

What are some treatments of GORD?

Answer 28

Conservative:
Weight loss
Avoid food/alcohol close to bedtime
Decrease alcohol
Raise head of bed 20-30cm

Medical:
proton pump inhibitors
decrease acid production

Surgical:
anti reflux surgery
repair hiatus hernia
vagotomy

Question 29

What is Barrett’s metaplasia?

Answer 29

Conversion of one type of mucosa to the other, with a change of epithelial type in response to environmental stress - change in the oesophagus from stratified squamous epithelia to simple epithelia

Question 30

What is the risk of oesophageal adenocarcinoma after GORD?

Answer 30

GORD is the pre-malignant condition for OAC with a 0.5% change to OAC per year with BM

Question 31

How can barrett’s metaplasia be managed?

Answer 31

management of symptoms of reflux

Question 32

What is Achalasia?

Answer 32

Failure of the oesophageal sphincter to relax meaning that food is not allowed down into the stomach characterised by regurgitations and bad breath.

Question 33

What treatments are available for achalasia?

Answer 33

Botox injections
oesophageal dilation
surgery