3. Digestive System
• Esophagus( tube that connects your mouth and
your stomach)
• Stomach
• Small Intestine
• Large Intestine
• Gall bladder
• Liver
• Pancreas
4. Stomach
• A stretchy bag that holds
your food after you eat.
Stomach has 4 major roles
in human body.
•
•
•
•
Esophagus
To store food
To mix the food with HCl and pepsin
To reduce the size of food particles
To empty the partially digested food
into the small intestine
Stomach
5. Stomach Cells
• Parietal cells (oxyntic cells) are the stomach epithelium cells
which secrete gastric acid.
• Parietal cells produce gastric acid
(hydrochloric acid) in response to
histamine (via H2 receptors),
acetylcholine (M3 receptors)
and gastrin (gastrin receptors).
• Parietal cells contain an extensive
secretary network (canaliculi)
from which the HCl is secreted by
active transport into the stomach.
7. Gastroesophageal Reflux Disease
(GERD
• Most common disorder of esophagus
• Characterized by regurgitation
of gastric contents into
esophagus and exposure
of esophageal mucous
to gastric acid and pepsin.
• Main symptom is heart burn –
occurs after eating.
9. Peptic Ulcer
• Condition characterized by
Erosion of GI mucosa resulting
from digestiveaction of
HCl and pepsin
• Ulcer development
– Lower esophagus
– Stomach
– Duodenum
10. Gastric Ulcer
• common in late middle age
– incidence increases with age
• Use of NSAIDs - associated with a three- to four-fold
increase in risk of gastric ulcer
• Less related to H. pylori than
duodenal ulcers – about 80%
• 10 - 20% of patients with a
gastric ulcer have a
concomitant duodenal ulcer.
11. Duodenal Ulcer
• Duodenal sites are common as gastric
sites
• Most common in middle age
• Male to female ratio—4:1
• Associated with increased serum
pepsinogen
• H. pylori infection common up to 95%
• Smoking is twice as common
12. Helicobacter Pylori (H. pylori)
• Helicobacter Pylori (H. pylori) is a spiral shaped bacterium
found in the stomach.
• H. pylori damages stomach and
duodenal tissue
• Causes 80% of peptic ulcers
• Survives the acid environment by
attaching to the sugar molecules that
line the stomach wall
• Uses the mucus layer as protection
13. Zollinger-Ellison Syndrome
• Zollinger-Ellison Syndrome is a rare disorder that causes one
or more tumors to form in the pancreas or
• upper part of the small
intestine called the
duodenum.
• The tumorsare called
gastrinomas, and they secrete
a large amountof the
hormone gastrin.
• In this syndrome increased levels of the hormone gastrin are
produced, causing the
stomach to produce excess
14. Release of Gastric Acid
• Histamine stimulates acid release by
interacting with the histamine receptor
• Acetylcholine activates the cholinergic
receptors
• Gastrin is released when
food is present in the stomach
15. Proton Pump Inhibitor
Mode of Action
Proton pump inhibitor that suppresses gastric
acid secretion by specific inhibition of the
H+/K+-ATPase in the gastric parietal cell.
Blocks the enzyme in the wall of the stomach
that produces acid.
16. Antacids
• Quick but short term
• Buffer gastric acid, increasing the pH
• Neutralize acid by the following reaction
NaHCO3 + HCl
NaCl + H2O + CO2
17. Dosage Schedule
Indication
Dose
Frequency
Short-Term Treatment of
Active Duodenal Ulcer
20mg
Once daily for 4 weeks
Benign Gastric Ulcer
40mg
Once daily for 4-8 weeks
Gastroesophageal Reflux Disease (GERD)
Symptomatic GERD (with
no esophageal erosions)
20mg
Once daily for up to 4
weeks
Erosive Esophagitis
20mg
Once daily for 4-8 weeks
Maintenance of Healing
of Erosive Esophagitis
20mg
Once daily