Some stimuli act as attention-getting stimuli due to their physical characteristics; others, due to their meaningfulness, act as attention-holding stimuli.
For example, somebody's physical appearance, of a person who is attractive, is used as an attention-getting stimuli, but their psychological qualities are what hold your attention due to their meaningfulness.
Breaking down food into smaller molecules. Absorbsion of nutriets taking place in the small intestine and elimination of waste products through the large intestine/ Colon