What are the components that make up the GIT on a cellular level?
Epithelium- stops things from the environment crossing and getting into the bodyLamina Propria- contains immune cells, fibroblasts, nerves, blood vesselsCircular muscle- works perpendicularly with longitudinal muscle to cause peristalsisLongitudinal muscle- works perpendicularly with circular muscle to cause peristalsisMesenteric plexus- causes pulses of muscle contraction
What are the functions of the GIT?
1. Food digestion2. Vomiting3. Fluid absorption4. Immulogical functions eg oral tolerance
How is gastric acid regulated in the stomach?
Cl- is pumped into the cell by antiport carrierCell becomes negatively chargedCell transports the Cl- into the lumen via a symport carrierK+ leaves the cell along with the Cl-A proton pump exchanges K+ for H+ to get the K+ back into the cellH+ and Cl- are in the lumen so HCL is produced.
What activates gastric acid secretion?
Acetylcholine from a nerve and Gastrin from the blood act on histamine releasing cells, causing histamine to be released.Histamine binds to a receptor in the parietal cell and activates the secretion of gastric acid.
Name 2 gastric acid related diseases.
GERD (gastro eosophogeal reflux disease)Peptic ulcer disease
What are gastric acid diseases caused by?
Excess acid productionWeak sphincterDecreased mucousInfection
What are the 4 pharmacological methods used to treat gastric acid related diseases?
1. Cytoprotective2. Antacids3.. H2 receptor antagonists4. Proton pump inhibitors5. Antibiotics
How do Cytoprotective drugs work? Give an example.
Coat the surface of the stomachBismuth Chelate
How do Antacids work? Give an example.
Neutralise gastric acidMagnesium Hydroxide
How do H2 receptor antagonists work? Give an example.
Inhibit the histamine receptorCimetidine
How do proton pump inhibitors work? Give an example.
Prevent HCL accumulation by blocking the pump.Omeprazole(Drug of choice, pH and cell specific)
How do antibiotics work? Give an example.
Kill the H. pylori bacteria that infects the stomach and causes inflammation that leads to peptic ulcer formation.Amoxillin