Clinical Introduction to GI tract Flashcards
What is the pathway that food goes through in the body?
Mouth Pharynx Oesophagus Stomach Small intestine (pancreas, liver, gall bladder) Large intestine
What is the name of the food ball formed during mastication?
Food bolus
What are the names of the three salivary glands and what do they secrete?
Which are more active at rest?
Parotid (strong serous liquid)
Submandibular (serous and mucous)
Sublingual (mucous)
Submandibular and sublingual
What are the 3 main functions of saliva?
- Digestive (chewing, bolus formation, amylase, lipase)
- Protective (dilution, buffering, lubrication, remineralisation, antimicrobial, healing, cleansing
- Additional (speech, excretion, trophic)
What are the three pharynx?
oro
naso
hypo
What is the name of the flap which stops food going down the trachea?
What happens in aspiration?
Epiglottis
Food goes into the trachea and can lead to suffocation or chest infections
What are the 4 layers in the oesophagus called?
- Adventitia (connective tissue - holds the oesophagus in place)
- Muscle layer (voluntary and smooth)
- Submucosa
- Mucosa
How long is a typical oesophagus and how many sphincters (muscle for constriction) does it have?
25cm
2
What is peristalsis and what muscle is in each third of the oesophagus?
Contractions to move food down the GI tract.
1st 1/3 = voluntary
2nd 1/3 = voluntary and smooth
3rd 1/3 = smooth
What epithelium type is found in the mucosa?
Non-keratinised stratified squamous epithelium
What is the oesophagus like when no food is going down it?
Closed and compact - able to collapse and move about to get food down.
Where do each of these pass the oesophagus?
Inferior Vena Cava = T8
Oesophagus = T10
Aorta = T12
What are the 4 places that gastric secretion comes from?
Saliva (bicarbonate, amylase)
Gastric (HCl)
Pancreatic (bicarbonate, lipase, amylase, protease)
Bile (bile salts, phospholipids, cholesterol)
What is the name of the exit of the stomach and entrance into the small intestine?
What is the name of the product?
Stomach - inside and outside level?
Duodenum via the pyloric sphincter
Chyme
Inside produces acid and outside is muscle for expansion
What is the name of ridges of muscle tissue which line the stomach?
Rugae
How long is the small intestine?
Apart from digestion, what else occurs here?
What is the name of the place drug absorption occurs?
6m
Absorption of vitamins and minerals, breakdown of drugs
Duodenum - it encourages pancreas to produce enzymes for digestion and the gall bladder to produce bile
Where does the liver, gall bladder and pancreas connect?
What is the point of bile?
Common bile duct and come out into the duodenum.
It is an emulsifier which allows your fats to be absorbed and digested.
What is the name role of the liver and the pancreas?
Liver = drug metabolism and coagulation factor production Pancreas = insulin production, serotonin production
Liver, gall bladder, pancreas:
Structure
Function
Liver S = hepatocytes, 4 lobes
Liver F = metabolism of drugs, produces clotting factors, produces bile
Gall bladder S = small pouch, below liver
Gall bladder F = concentration of bile
Pancreas S = endocrine and exocrine cells
Pancreas F = regulating blood sugars, digestion
What causes gall stones in the liver?
Lots of bile salts building and congealing up
Gives a right sided pain where bile cannot pass through the gall bladder
How is the way that the appendix placed affect digestion?
If it is bent, the product will build up and so will bacteria. Inflammation occurs and this leads to infection. The appendix can then burst and stomach acid can leak into surrounding tissue.
Main roles of large intestine
(Waste product flows through, absorption of water and make the product more alkali for excretion)
- Absorbing water (completing the process of digestion)
- Absorbing vitamins (the large intestine also helps in absorption of vitamins due to bacteria here)
- Reducing acidity
- Defending from infections
- Producing antibodies (the appendix is a confluence of several lymphoid tissues)
What are the two forms of oral manifestation of GI disease?
- Dental
- Mucosal (direct contact or indirect absorption)
Explain the direct and indirect dental defects of GI disease
Give some examples of the disease
Direct (acid erosion and dietary acid)
Indirect (malabsorption, medication for the GI disease, GI disease itself)
Enamel defects, hypo-calcification, too much fluoride
Why is non carious tooth surface loss hard to treat?
It is due to acid which makes the tooth very smooth.
Hard to bond composite to it so crowning these teeth may need to occur.
What are the two types of inflammatory bowel diseases and explain each?
Ulcerative Colitis
- Affects part or whole of large intestine (tends not to affect the small intestine)
- Causes inflammation and ulcers (ulcers in the smooth tissue so the digestive products can leak into other body tissues)
- 15-40yrs
Crohn’s disease
- Usually starts in teens or early twenties
- Causes abdominal pain, diarrhoea, fever, anaemia and weight loss, skin rashes
What is orofacial granulomatosis?
OFG is an uncommon condition in which patients have persistent swelling in the lips, face or areas within the mouth. It gets its name from small groups or collections of inflammatory cells which can be seen when the swollen tissue is examined under the microscope. These collections are called granulomas.
It responds well to steroids.
Why is GI disease of dental relevance?
- Oral manifestations (ulcers, swelling, gingival enlargement)
- Effects of malabsorption
- Effects of corticosteroids (much more prone to infections, puts blood pressure up, hypertension, mood changes, makes weak bones so more prone to fractures)
- Effects of immunosuppressives
Explain coeliac disease and the dental relevance of this
- Genetic
- Hypersensitivity of small intestine mucosa to gliadin component of gluten
- Villous atrophy (villi become flat , reduced SI and absorption which can lead to anaemia, malabsorption, lose B12, oral ulceration)
- Malabsorption
- Herpetiform ulcers (groups)
Tests for it: blood test to see if you produce antibodies to gluten (only 60% accurate) and a biopsy from the small intestine to get some tissue and send it to the lab.
Dental relevance:
- Problems relate to malabsorption
- B12, folate, glossitis, burning mouth, anaemia
- Vitamin K (bleeding)
- Minerals (weakness)
- Enamel defects if started in childhood
