Mouth and Oesophagus Flashcards
1
Q
Define the process of digestion
A
- Conversion of dietary nutrients into a form that the small intestines can absorb
2
Q
What are the 3 structures in the mouth that are important in digestion
A
- Teeth
- Tongue
- Salivary glands
3
Q
What are the functions of the tongue
A
- Receptors on the tongue allow for taste and identifying what is in the mouth.
- Facilitate movement of food
- Assist in swallowing
4
Q
What are the functions of the mouth
A
- Mastication to increase SA for more efficient digestion
- Initiation of metabolism of carbohydrates and fats
- Lubrication - to cover the food bolus in saliva to allow for swallowing
5
Q
What is the function of the oesophagus
A
- Act as a conduit
6
Q
What are the names of the glands that produce saliva
A
- Parotid gland
- Sublingual gland
- Submandibular
7
Q
How do salivary glands acts as exocrine glands
A
- They produce lipase and amylase
8
Q
What do salivary glands produce when acting as secretory organs
A
- Mucous
- Fluid
- IgA
- Lysozyme
- Lactoferrin
9
Q
What 2 types of cells make up the structure of the salivary glands
A
- Acinar cells
- Ductal cells
10
Q
What is the function of acinar cells
A
- Produce enzymes which enter the mouth
11
Q
What is the function of ductal cells
A
- Secrete water and electrolytes
- Modifies secretions of acinar cells into the mouth
12
Q
What is the total volume of saliva secreted every 24hrs
A
- 1.5L
13
Q
What is the histological type of saliva produced by each of the 3 salivary glands
A
- Parotid = Serous
- Submandibular = Mixed
- Sublingual = Mucous
14
Q
What is the secretion of each of the 3 salivary glands like
A
- Parotid = Water
- Submandibular = Viscous +
- Sublingual = Viscous ++
15
Q
What is the % of secretion by each of the 3 salivary glands
A
- Parotid = 20
- Submandibular = 70
- Sublingual = 10
16
Q
Why is hydration provided by the saliva important
A
- Keeps the oral cavity moist to prevent dehydration of cells and eventually death
17
Q
Why is cryoprotection provided by the saliva important
A
- Protects the oral and oesophageal mucosa from damage
18
Q
Describe the immune functions of some of the substances secreted by salivary glands
A
- IgA - Antibodies that bind to pathogenic antigens
- Lactoferrin - Binds to iron and is bactericidal
- Lysozyme - Attacks bacterial cell walls causing cell lysis
19
Q
Why is saliva hypotonic and alkaline
A
- Salivary duct cells extract Na+ and Cl- and secrete K+ and HCO3-
20
Q
What are the benefits of having alkaline saliva
A
- Protects teeth from bacterial acid
- Neutralises gastric acid that refluxes in the oesophagus
21
Q
What is Sjogren’s syndrome
A
- Autoimmune attack of salivary and tear glands which results in dry mouth (xerostomia) and eyes.
- Commonly affects women, is associated with rheumatoid arthritis.
22
Q
What is Mumps virus (Parotitis)
A
- Swelling of the parotid glands
- Associated with orchitis (inflamed testicles)
- Early symptom of fever +headache
- Can be prevented with MMR vaccine
23
Q
What divisions of the nervous system control the secretion of the salivary glands
A
- Autonomic nervous system mostly via parasympathetic nervous system
24
Q
What are the source and root ganglion of the nerve that innervates the submandibular and sublingual glands in the parasympathetic NS
A
- Source - Cranial nerve VII (facial nerve)
- Ganglion - Submandibular ganglion
25
What are the source and root ganglion of the nerve that innervates the parotid gland in the parasympathetic NS
- Source - Cranial nerve IX (Glossopharyngeal nerve)
- Ganglion - Otic ganglion
26
What is the source and root ganglion of the nerve that innervates the salivary glands in the sympathetic NS
- Source - Thoracic sympathetic
- Ganglion - Superior cervical ganglion
27
What are the 4 stages of swallowing
- Oral preparatory phase
- Oral phase
- Pharyngeal phase
- Oesophageal phase
28
What is the oral preparatory phase of swallowing
- Manipulation and mastication of food in the mouth to turn it into a consistency that can be swallowed
29
What is the oral phase of swallowing
- The tongue pushes food posteriorly until the pharyngeal swallow is triggered
30
What is the pharyngeal phase of swallowing
- Bolus is transported through pharynx, glottis closure via movement of the epiglottis, cessation of breathing and relaxation of upper oesophageal sphincter (UOS) must occur at the same time.
31
What is the oesophageal phase of swallowing
- Oesophageal peristalsis carries the bolus from the UOS through the oesophagus to the lower oesophageal sphincter
32
What is the name of the structure that the oesophagus and vagus nerve pass through
- Oesophageal hiatus
33
Describe the structure of the oesophagus with regards to muscles
- Top 1/3 is composed of striated muscle
- Middle 1/3 is composed of a mixture of straited and smooth muscle
- Bottom 1/3 is composed of smooth muscle
34
What is the normal GI structure and does the oesophagus have this structure
- Mucosa (stratifies squamous epithelium)
- Inner circular muscle
- Outer longitudinal muscle
YES OESOPHAGUS HAS THIS STRUCTURE
35
What is Gastro-oesophageal reflux disease (GORD)
Chronic symptoms or mucosal damage caused by the abnormal reflux in the oesophagus
36
What are the risk factors of GORD
- Anything that increases intraabdominal pressure (obesity, pregnancy)
- Hiatus hernia (a portion of the stomach enters the thorax)
- Some drugs that relax LOS
- Zollinger Ellison's syndrome (producing excess acid)
37
What are the 2 types of Hiatus hernia and state there relative percentages of occurrence
- Sliding, 80%
- Rolling, 20%
38
How does a sliding hiatus hernia occur
- The abdominal part of the oesophagus slides upwards through the diaphragmatic hiatus into the thorax.
39
How does a rolling hiatus hernia occur
- The gastric fundus moves upwards and lies alongside a normally positioned Gastro oesophageal junction creating a 'bubble' in the thorax
40
Name some symptoms of GORD and explain why they happen
- Heartburn (retrosternal discomfort)
- Dysphagia (Inflammation of stricture)
- Laryngopharyngeal reflux (characterised by chronic cough)
41
What are some of the outcome of GORD
- Oesophagitis - damage to mucosal lining
- Stricture - Narrowing of oesophageal lumen
- Barret's metaplasia - Change in mucosal layer due to damage
- Oesophageal adenocarcinoma - Type of oesophageal cancer.
42
How is GORD diagnosed
- 24hr pH monitoring
- Contrast swallowing
43
what are the 3 stages of GORD treatment
- Conservative -
- Medical
- Surgical
44
Give examples of conservative treatments for GORD
- Weight loss
- Avoid food/ alcohol before bed
- Decrease alcohol intake
- Raise head of bed by 20-30cm
45
Give examples of medical treatments for GORD
- Decrease acid - proton pump inhibitors, H2 blockers
- Antacids to increase pH
- Alginates to neutralise acid (gaviscon)
46
Give examples of surgical treatments for GORD
- Anti reflux surgery 'fundoplication'
- Repair hiatus hernia
47
What percentage of patients with GORD are diagnosed with Barrett's metaplasia
- 10%
48
What percentage of patients with Barrett's metaplasia are diagnosed with oesophageal adenocarcinoma
0.5%
49
What is the change in the mucosa that occurs in Barrett's metaplasia and why does this change occur
- From stratified squamous epithelium to columnar single lined epithelium.
- Protective mechanism
50
How can the risk of a patient with Barret's Metaplasia developing a malignant progression be measured
- Surveillance endoscopy
51
What makes surveillance endoscopy for patients with Barret's Metaplasia controversial
- Expensive
- Labour intensive
- Only 0.5% of BM patients progress to adenocarcinoma
52
What are the two methods currently being discussed in research to identify biomarkers that identify BM patients at risk of adenocarcinoma
- Capsule and abrasive sponge for oesophageal lining cells.
- Breath test, test for biomarkers in breath of patient
53
What are the two types of oesophageal cancers
- Squamous cell carcinoma
- Adenocarcinoma
54
What is achalasia
- Failure of the gastroesophageal sphincter to relax
55
What are some symptoms of achalasia
- Dysphagia of both solids and liquids
- Regurgitation
- Chest discomfort
- Halitosis
56
How can achalasia be treated
- Botox to relax the GOS
- Oesophageal dilation, use a balloon to open up the sphincter
- Surgery, Heller's myotomy
