Functions of the Mouth & Oesophagus Flashcards Preview

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Flashcards in Functions of the Mouth & Oesophagus Deck (55)
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1
Q

Define digestion.

A

The conversion of dietary nutrients into a form that the small intestine can absorb.

2
Q

What is the function of mastication?

A

To increase surface area for digestion.

3
Q

Which enzymes initiate carbohydrate and fat metabolism?

A

Salivary amylase and lipase.

4
Q

List the names of all of the salivary glands.

A

1 - Parotid (and accessory parotid).

2 - Sublingual.

3 - Submandibular.

5
Q

List 3 secretions of salivary glands that serve antibacterial functions.

A

1 - IgA.

2 - Lysozymes.

3 - Lactoferrin.

6
Q

What is the function of acinar cells in salivary glands?

A

To produce enzymes.

7
Q

What is the function of ductal cells in salivary glands?

A

1 - To produce mucus (goblet cells).

2 - To secrete water and electrolytes.

8
Q

Give the % of total secretion represented by the parotid, submandibular and sublingual glands.

A

Parotid - 20%

Submandibular - 70%

Sublingual - 10%

9
Q

How are the secretions of the parotid gland conveyed to the mouth?

A

Through the parotid duct.

10
Q

Are the secretions of the parotid gland serous, mucous or mixed?

A

Serous.

11
Q

Are the secretions of the submandibular gland serous, mucous or mixed?

A

Mixed

12
Q

Are the secretions of the sublingual gland serous, mucous or mixed?

A

Mucous

13
Q

How does lactoferrin work?

A

Lactoferrin binds iron, limiting the amount of ions available for microorganisms’ metabolism.

14
Q

Why is saliva hypotonic and alkaline?

A

Because salivary duct cells extract Na+ and Cl- from the blood and secrete K+ and HCO3-.

15
Q

List 2 advantages of saliva being alkaline.

A

1 - Protects teeth from bacterial acids.

2 - Neutralises gastric acid that refluxes into the oesophagus.

16
Q

What is Sjögren’s syndrome?

Who is most commonly affected?

What is the syndrome associated with?

A
  • An autoimmune attack of salivary and tear glands which results in dry mouth and eyes.
  • Commonly affects women and is associated with rheumatoid arthritis.
17
Q

What is parotitis?

A
  • Inflammation of a parotid gland.

- Associated with mumps.

18
Q

In which ganglion does the facial nerve synapse with the post-synaptic counterpart that is responsible for the stimulation of the submandibular and sublingual glands?

A

The submandibular ganglion.

19
Q

In which ganglion does the glossopharyngeal nerve synapse with the post-synaptic counterpart that is responsible for the sitmulation of the parotid gland only?

A

The otic ganglion.

20
Q

In which ganglion do thoracic sympathetics synapse with the post-synaptic counterparts that are responsible for the sitmulation of all salivary glands?

A

The superior cervical ganglion.

21
Q

What is xerostomia?

A

Dry mouth resulting from reduced or absent saliva flow.

22
Q

What are the 4 phases of swallowing?

A

1 - Oral preparatory phase.

2 - Oral phase.

3 - Pharyngeal phase.

4 - Oesophageal phase.

23
Q

Describe the oral preparatory phase of swallowing.

A

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

24
Q

Describe the oral phase of swallowing.

A

The tongue propels the bolus posteriorly until the pharyngeal phase is triggered.

25
Q

Describe the pharyngeal phase of swallowing.

A

The bolus is transported through the pharynx with:

  • Coordinated closure of the glottis via movement of the epiglottis.
  • Cessation of breathing.
  • Relaxation of the upper oesophageal sphincter.
26
Q

Describe the oesophageal phase of swallowing.

A

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

27
Q

Which 4 cranial nerves compose the swallowing centre in the medulla oblongata?

A

1 - Trigeminal nerve (V)

2 - Glossopharyngeal nerve (IX)

3 - Vagus nerve (X)

4 - Hypoglossal nerve (XII)

28
Q

Is pseudobulbar palsy a result of damage to an upper or lower motoneurone?

A

Upper.

29
Q

Is bulbar palsy a result of damage to an upper or lower motoneurone?

A

Lower.

30
Q

List 3 symptoms of pseudobulbar and bulbar palsy.

A

1 - Difficulty in swallowing.

2 - Altered speech.

3 - Loss of gag reflex, can lead to aspiration of food / fluid into the trachea.

31
Q

Briefly summarise the embryological development of the trachea.

A
  • The trachea develops as lung buds from the oesophagus.

- As the trachea matures it comes to lie anterior to the oesophagus.

32
Q

List 2 congenital problems of the trachea.

A

1 - Tracheoesophageal fistula (abnormal passageway between the trachea and oesophagus).

2 - Oesophageal atresia.

33
Q

What is GORD?

A
  • Gastro-oesophageal reflux disease.

- Chronic symptoms of mucosal damage produced by the abnormal reflux in the oesophagus.

34
Q

List 5 causes of GORD.

A

1 - Obesity.

2 - Hiatus hernia (part of the stomach slides or rolls up to the chest).

3 - Drugs that lower tone at lower oesophageal sphincter.

  • Anti cholinergic.
  • Beta agonists.
  • Benzodiazepenes.

4 - Pregnancy.

5 - Zollimger Ellison syndrome.
- Gastrin secreting tumour.

35
Q

List 6 symptoms of GORD.

A

1 - Heartburn.

2 - Regurgitation.

3 - Dysphagia (swallowing difficulties).

4 - Cough.

5 - Hoarsness (change in voice).

6 - Chronic earache.

36
Q

List 2 diagnostic methods that can be used to diagnose GORD.

A

1 - 24 pH monitoring (defines reflux).

2 - Contrast swallow (demonstrates reflux).

37
Q

List 4 conservative treatments for GORD.

A

1 - Weight loss.

2 - Avoid food / alcohol close to bed time.

3 - Decrease alcohol.

4 - Raise head of bed 20-30cm.

38
Q

List 4 medical treatments for GORD.

A

1 - Proton pump inhibitors (decrease acid).

2 - H2 blockers (decrease acid).

3 - Antacids (increase pH).

4 - Alginates, e.g. Gaviscon (coat mucosa).

39
Q

List 3 surgical treatments for GORD.

A

1 - Fundoplication (upper curve of the stomach (the fundus) is wrapped around the oesophagus and sewn in place).

2 - Repair hiatus hernia.

3 - Vagotomy (removal of all or part of the vagus nerve).

40
Q

What is Barrett’s metaplasia?

A

A change of epithelial type in the oesophagus in response to environmental stress.

41
Q

Name a cause of Barrett’s metaplasia.

A

GORD.

- 10% of GORD patients develop BM.

42
Q

Name a complication of Barrett’s metaplasia.

A

Oesophageal adenocarcinoma.

43
Q

What is an adenocarcinoma?

What is an adenoma?

What is a carcinoma?

A
  • An adenocarcinoma is a malignant adenoma.
  • An adenoma is a benign tumour of glandular tissue.
  • A carcinoma is a tumour of epithelial tissue.
44
Q

How does Barrett’s metaplasia change the epithelium lining the oesophagus?

A

Changes from stratified squamous epithelium to columnar epithelium.

45
Q

What is achalasia?

A
  • A motor disorder of the oesophagus, causing a loss of myenteric plexus at the lower oesophageal sphincter.
  • This causes the lower oesophageal sphincter to relax poorly.
46
Q

List 4 symptoms of achalasia.

A

1 - Dysphagia.

2 - Regurgitation.

3 - Chest discomfort.

4 - Halitosis (bad breath).

47
Q

List 3 treatments for achalasia.

A

1 - Botox injection at the lower oesophageal sphincter.

2 - Oesophageal dilation.

3 - Surgery (Heller myotomy).
- Muscles of the lower oesophageal sphincter are cut.

48
Q

What is a pharyngeal pouch?

A

A posterior defect between the cricopharygeus and the inferior constrictor (Killian’s dehisence).

49
Q

List 3 symptoms of pharyngeal pouch.

A

1 - Dysphagia.

2 - Regurgitation.

2 - Halitosis.

50
Q

List 4 causes of oesophageal rupture.

A

1 - Endoscopy.

2 - Trauma.

3 - Vomiting.

4 - Boerhaave’s syndrome (a spontaneous perforation of the esophagus that results from a sudden increase in intraesophageal pressure combined with negative intrathoracic pressure).

51
Q

List 4 symptoms of oesophageal rupture.

A

1 - Chest pain.

2 - Subcutaneous emphysema (air trapped under the skin).

3 - Sepsis.

4 - Pleural effusion.

52
Q

What are oesophageal varices?

A

Extremely dilated sub-mucosal veins in the lower third of the oesophagus

53
Q

What causes oesophageal varices?

A

Pre-Hepatic:

  • Portal hypertension.
  • Portal vein thrombosis.
  • External compression of portal vein by tumours.

Post-Hepatic:

  • Right heart failure.
  • Budd-Chiari syndrome (occlusion of the hepatic veins that drain the liver).
  • Also cirrhosis.
54
Q

List 3 complications of portal hypertension.

A

1 - Variceal bleeding.

2 - Ascites (accumulation of protein-containing (ascitic) fluid within the abdomen).

3 - Encephalopathy (brain damage).

55
Q

List 2 medical therapies for oesophageal varices.

What are their effects?

Suggest a surgical therapy.

A

1 - Beta blockers.

2 - Nitrates.

Both decrease portal pressure.

Liver transplant as a surgical therapy.