1. Structure, Characteristics and Regulation of the Stomach
Chapter 17
Pages

2. General Characterisics
J-shaped “Pouch”
Upper-left abdominal area
Extra Layer of Muscle
Mixing
Rugae
Regions:
Cardia
Fundus
Body
Pylorus
Pyloric Sphincter
Hypertrophic Pyloric Stenosis

3. Gastric Secretions Gastric Pits/Glands  Produce Gastric Juice
Chyme – mixture of food & gastric juice
Cells and What they Produce
Mucous  Mucus
Protection
Ulcers
Parietal  HCl
Activates pepsinogen
Chief  digestive enzymes
Pepsin – most important; Proteins
Produced as pepsinogen (inactive)
Gastric Lipase – Fats
Intrinsic Factor – absorption of B12

4. Regulation Controlled by nervous system & hormones
Parasympathetic – increase activity
Vagus
Causes the release of Gastrin
Hormones
Gastrin – increases
Gastric glands
Somatostatin – decreases
Parietal cells
Cholecystokinin – decreases activity
Small intestines
Intestinal Somatostatin – decrease activity
Phases
Cephalic
Before
Gastric
During
Alkaline Tide
Intestinal
after

6. Mixing & Emptying Very Little Absorption
H2O, Alcohol
Rate of emptying depends on Food Type
Carbs (quickest)  Proteins  Fats (slowest)
Enterogastric Reflex
Slows movement of chyme to small intestines
Vomiting Reflex
Quick and Backwards
Nausea