Assimilation and Egestion

Assimilation is the process by which absorbed food material finally reaches the body's tissues and becomes incorporated into the protoplasm of its cells.

Egestion is the expulsion of undigested waste. In the colon, undigested material is converted into faeces — which contains water, inorganic salts, sloughed-off mucosal cells, bacteria, and undigested food — and this faecal matter passes into the rectum. As the rectum becomes distended (stretched) with faeces, pressure-sensitive receptors in its wall are stimulated, initiating a neural reflex for defaecation. Defaecation (eges …