extracellular digestion

The ciliated columnar cells, teeming with cilia and mitochondria, play the part of food transportation, intracellular and extracellular digestion.

纤毛柱状细胞有密集的纤毛和丰富的线粒体，具有运输食物、细胞内消化和细胞外消化的功能；

Perhaps the simplest approach to extracellular digestion is that employed by saprophytes.

细胞外消化最简单途径也许是腐生生物所利用的方法.

The secretory cells can secrete digestive enzymes and mucus mixtures that the former can participate in extracellular digestion of intestinal lumen and the later play an important role in lubricating lumen, cohering food particles and protecting mucosa.

分泌细胞以顶浆分泌方式分泌酶原和粘液，其分泌的酸性和中性混合粘液物质可起到润滑肠道、保护粘膜的作用，分泌的消化酶参与肠腔中进行的细胞外消化。

The ciliated columnar cells have the function of food transportation, as well as intracellular and extracellular digestion and energy storage in lipid drops and glycogen particles.

纤毛柱状细胞除了能运输食物外，还具有细胞内消化、贮存能量及细胞外消化的功能；