Mechanically breaks up food particles, liquifies the food & begins chemical digestion of protein & fat
Regenerative cells divide rapidly to produce new cells that migrate upwards towards surface.Chief cells secrete chymosin & lipase in infancy & pepsinogen throughout life
Secrete peptide hormone, gastrin, which is released into bloodstream and increases secretory activity of gastric glands.
secreted in sm. amounts at sight or smell of food—parasympathetic response that ensures some gastric juice will be present in stomach when food arrives.
Swallowing center signals stomach to relax
Arriving food stretches the stomach activating a receptive-relaxation response
Induced by excessive stretching of stomach, psychological stimuli or chemical irritants (bacterial toxins)
Pancreas, Liver and Gallbladder
All release important secretions into small intestine to continue digestion
"backup" enzyme for salivary amylase.
breaks down starches into maltose
Stores bile between meals
Concentrates bile by reabsorbing water (concentrates bile 20 fold).
Releases bile into small intestine.
Passage of substances e.g., digested foods, water, salts, and vitamins) through intestinal mucosa into blood or lymph.