Clinical Intro to GI Tract Flashcards
What does the GI tract do?
Takes in food
Digests to extract and absorb energy and nutrients
Expels remaining waste
What is formed at the end of mastication?
Bolus
What are the three main salivary glands involved with eating?
Parotid
Sublingual
Submandibular
What type of saliva is produced by the parotid?
Serous
What type of saliva is produced by the submandibular?
Mixed
What type of saliva is produced by the sublingual?
Mucous
Which salivary gland is most active during eating/chewing?
Parotid
What are the digestive functions of saliva?
Form bolus
Amylase and lipase
Taste
What are the protective functions of saliva?
Dilution
Buffering
Lubrication
Remineralisation
Antimicrobial/antifungal/healing
What are the three regions of the pharynx?
Nasopharynx
Oropharynx
Hypopharynx
What prevents aspiration when you swallow?
Epiglottis
How long is the oesophagus on average?
25cm
How is food moved along the oesophagus?
Peristalsis
What are the four layers of the oesophagus?
Mucosa
Submucosa
Muscle layer
Adventitia
Describe the muscle arrangement of the oesophagus.
Upper third - voluntary
Middle third - mixed
Lower third - smooth
Describe the epithelium of the oesophagus.
Non-keratinised, stratified, squamous epithelium
At what level does the oesophagus pass through the diaphragm?
T10
At what level does the inferior vena cava pass through the diaphragm?
T8
At what level does the aorta pass through the diaphragm?
T12
What increases the secretion of saliva?
Parasympathetic and sympathetic stimulation
What decreases the secretion of saliva?
Sleep
Dehydration
Atropine
What are the characteristics of saliva?
Hypotonic
High HCO3- and K+
Contains α-amylase and lingual lipase
What increases the secretion of gastric acid?
Gastrin
Acetylcholine
Histamine
What decreases the secretion of gastric acid?
Chyme in duodenum
Somatostatin
Atropine
Cimetidine
Omeprazole
What increases the secretion of bile?
Cholecystokinin
Parasympathetic stimulation
What decreases the secretion of bile?
Ileal resection
What are the characteristic substances found in bile?
Bile salts
Bilirubin
Phospholipids
Cholesterol
What increases pancreatic secretion?
Parasympathetic stimulation
Secretin
Cholecystokinin
What are the characteristics of pancreatic secretions?
Isotonic
High HCO3-
May contain pancreatic amylase, lipase, protease or pepsinogen or intrinsic factor
Which amylase is stronger?
Pancreatic
What does the stomach secrete?
Acid
Enzymes
What are rugae?
Ridges of muscle tissue lining stomach
How many muscle layers are there in the stomach’s muscularis externa?
Three
What opens to allow chyme to move into the duodenum?
Pyloric sphincter
How many lobes are in a human liver?
4
What are the functions of the liver?
Drug metabolism
Produce clotting factors
Produce bile
What are the cells of the liver called?
Hepatocytes
What is the function of the bladder?
Stores and concentrates bile
What is the common risk group for gall stones?
Females
40+
Fatty diet
What is the endocrine function of the pancreas?
Regulate blood glucose by producing glucagon or insulin from islets of Langerhans
What is the exocrine function of the pancreas?
Produce digestive enzymes
What separates the small and large intestines?
Ileo-caecal valve
What occurs in the large intestine?
Absorption of water
Absorption of vitamins made by bacteria
Reduction in acidity
Infection defence
How does defence against infections occur in the large intestine?
Antibodies produced - especially by appendix
Confluence of several lymphoid tissues for surveillance
What is an example of a direct dental defect?
Acid erosion by intrinsic acid reflux or extrinsic dietary acids
What is an example of an indirect dental defect?
Malabsorption (medical conditions, drugs)
What may result in enamel not forming or being translucent?
Hypercalcificaiton
Fluorosis
What are two inflammatory bowel diseases?
Ulcerative colitis
Crohn’s disease
What part of the GI tract does ulcerative colitis affect?
Part/whole of large intestine
What is ulcerative colitis?
Inflammation, ulcers and pseudopolyps
Bacteria can leave GI tract into blood
What are the oral manifestations of ulcerative colitis?
Oral ulceration
Blood blisters
Pyogenic granulosum
Erythema
What is the characteristic timeline of Crohn’s disease?
Starts in teens/early twenties
Second peak in old age - 50-60yo
What symptom might indicate Crohn’s disease?
Recurrent oral ulcers
What are the symptoms of Crohn’s disease?
Intermittent abdominal pain, diarrhoea, abdominal distention
Fever
Anaemia and weight loss
Melaena
Fistulae and perianal sepsis
Finger clubbing
Uveitis, arthritis, skin rashes/erythemanodosum
What is orofacial granulamatosis?
Group of non-infectious, idiopathic disorders
Histologically associated with non-caseating epitheloid granulomas and multinucleated Langhan’s giant cells within oral mucosa
What does orofacial granulamatosis respond well to?
Injection steroids
What is orofacial granulamatosis associated with?
Preservatives in diet
What are some symptoms of orofacial granulamatosis?
Cracking
Oral ulcerations
Lip/soft tissue swelling
Staghorning
What are the possible oral manifestations of inflammatory bowel diseases?
Ulcers
Swelling (facial or labial)
Mucosal tags
“Cobblestone” proliferation of mucosa (buccal)
Smoothing of tongue
Angular cheilitis
Gingival enlargement (secondary to drugs)
Staghorning
What drugs may patients with IBD be taking?
Immunosuppressants
Corticosteroids
What should you be aware of in patients with IBD?
Treat bacterial infections more aggressively
Gingival swelling
Hypertension, MI, hypotensive crises, cerebrovascular accidents
HPA-axis suppression, impaired glucose tolerance, diabetes, osteoporosis, growth retardation
Peptic ulceration
Delayed wound healing and poor quality tissues
What is Coeliac disease?
Genetic hypersensitivity of small intestine mucosa to gliadin (in gluten) characterised by villous atrophy
What are the two tests for Coeliac disease and which is more reliable?
Blood tests to see if you produce gluten antibodies
Small intestine biopsy - more reliable
What is the dental relevance of Coeliac disease?
Malabsorption of vit. B12, folate - beefier tongue
Anaemia, iron-deficient
Glossitis, burning mouth, angular stomatitis, recurrent oral ulceration
Why is malabsorption of vit. K important?
Patient will be prone to bleeding
Why is malabsorption of vit. D important?
Osteomalacia (adults)
Rickets (children)
What does angular stomatits indicate?
Iron deficiency or fungal infection
What type fo ulcers do Coeliac disease patients tend to have?
Herpetiform (clusters)
