(a) Muscles of stomach: They bring about churning movement that breaks food into small particles and mixes it with gastric juice.
(b) Hydrochloric acid: It is a gastric secretion which softens, sterilises and acidifies the food for action of enzyme pepsin.
(c) Mucus: It lubricates the food passing through the alimentary canal and protects the wall of digestive tract from digestive enzymes.
