外套膜

外套膜简称套膜. 软体动物和腕足动物壳内的 体壁褶.套膜通常由３层组成.软体动物套膜的外层为表皮层，含许多 腺细胞，能分泌 贝壳.中层最厚，为皮层，由肌肉与结缔组织交织而成.内层亦为表皮层，常生有纤毛，依靠纤毛摆动获得 呼吸、排泄等生理功能需要的水流及食物.腕足动物的套膜与壳紧密结合，由套膜外层表皮伸出许多含分泌细胞的管状突起达到壳的 角质层.Referred to as sets of films. Mollusc and brachiopod shell of the body wall folds. Sets of film is usually composed of three layers. Mollusk sets of the outer membrane of the epidermis, containing a number of glandular cells, can secrete shells. The middle of the most thick, as the cortex from the muscle and connective tissue interwoven. inner layer of the epidermis is also often gave birth to cilia, relying on ciliary beat was breathing, excretion and other physiological functions need water and food. brachiopod set of membrane and the shell closely, from sets of film outer layer of skin stretched out a number of tubular processes containing secretory cells of the stratum corneum to reach the shell.