Neural and hormonal control
Cephalic phase Brain activated by smell, sight, thought, taste of food. Neurons to salivary glands and gastric glands/stomach muscles Autonomic nervous system
Gastric phase Stimulus: food in stomach Neural: Stretch receptors activated. Impulse to neurons in submucosa. Triggers: –gastric gland production and causes peristalsis. Hormonal: Food triggers release of gastrin (hormone). Goes in blood. Triggers: –gastric gland juices, –sphincter to prevent acid-reflux, –stomach muscles –relaxes lower stomach sphincter.
Intestinal phase Stimulus: food in intestines Neural: stretch receptors to medulla oblongata. Sympathetic nerves to stomach cause: decreased stomach movement and increase contraction of pyloric – bottom - sphincter (delays stomach emptying) Hormonal: Cholecystokinin (CCK): stimulates pancreatic juice/squeezes gallbladder