Mouth and oesophagus

parotoid, submandibular and sublingual

lubrication, hydration, cytoprotection, immune protection and digestion (mainly for detection by taste cells)

Acinar

Modify saliva’s composition uptake NaCL secrete HCO3 and K + makes saliva hypotonic and alkaline

viral infection, saliva glands swollen (particularly parotid glands) orchitis also a symptom in mean

1.5L

autoimmune attack of saliva and tear glands resulting in dry mouth and eyes. Commonly associated with rheumatoid arthritis and more common in women

autonomic nervous system, primarily the parasympathetic nervous system

• Mouth phase - chewed to increase surface area to volume ratio aid swallowing / digestion • Oral phase- tongue propels food posteriorly until the pharyngeal swallow is activated • Pharyngeal phase - once pharyngeal is activated the bolus is transported through the pharynx, this occurs at the same time as closing of the glottis via the epiglottis movement, cessation of breathing and relaxation of the upper oesophageal sphincter (UOS) • Oesophageal phase - oesophageal peristalsis carries the bolus from the UOS to the lower oesophageal sphincter

dysfunction of LOS- can be due to drugs that relax it (e.g. anticholinergic drugs) can be due to hiatus hernia increase in intra-abdominal pressure - obesity, pregnancy, hiatus hernia

heart burn and retrosternal discomfort, following eating / eating down etc dysphagia (difficulty swallowing) Laryngopharyngeal reflux - chronic cough, horse voice secondary to reflux into the pharynx

change of epithelial tissue in response to environmental stress

A pre-malignant condition, where the normal squamous epithelial lining is replaced by intestinal metaplasia epithelium, often due to repeated irritation from GORD increases risk of oesophageal adenocarcinoma

24-hour PH monitoring- a probe down oesophagus contrast swallow - barium meal to see the areas of damage

conservative measures include, weight loss, decreasing alcohol and avoiding alcohol/ food close to bed time medical treatments = PPI’s e.g. omeprazole, H2 blockers, antiacids (Gaviscon) surgical - repairing hernias, or fundoplication (anti-reflux surgery, rarely used has side effects)

motor disorder - failure to relax LOS, sphincter too tight for food to enter symptoms include dysphagia solids and liquids, regurgitation, chest discomfort halitosis

• Basal phase - low acid levels follows a circadian rhythm acid levels low in the pm high in the am • Cephalic phase - smell, sight, taste, swallowing of food initiates this phase, which is mediated by the vagus nerve. 30% of acid made before food enters stomach • Gastric phase - food entered stomach all other mechanisms mentioned earlier activated 50-60% acid secretion made here • Intestinal phase - partially digested peptides / amino acids in proximal part of small intestine trigger some gastrin to be produced by duodenal G cells 5-10% stomach secretion produced

CFTR channel, cystic fibrosis transmembrane regulator

Cl- cannot be efficiently recycled through CFTR as its prematurely degraded this reduces water levels in pancreatic duct, also causes deficiencies in HCO3 secretion (due to lack of Cl for HCO3 / Cl exchanger) this results in thick mucus can cause blockages and pancreatitis increases risk of diabetes this lack of secretions reaching the duodenum leads to malnutrition

• Cephalic phase - sight, smell , taste etc. = 25% total secretion. Mediated by only Ach primary focus on the acinar cells not duct cells • Gastric phase - 10-20% Gastrin release - weak CCK agonist some production, neural pathways stimulated by stomach distention through a vagovagal gastropancreaitc reflex • Intestinal phase - 50-80% via all pathways Ach, lipids-CCK, neural pathways

Hypochloridria and gastritis, causes ILB release which inhibits gastrin release, leading to reduced acid secretion and stomach ulcers

Lead to G cells to hyper secrete gastrin, hypergastrinemia excess acid production, peptic ulcers

secrete inactive proteases such as pepsinogen, which is converted to pepsin at PH 3, and inactivated at PH 7.2

Low PH in the antrum causes D cells to produce somatostatin