Within them are mucus and thread cells.

黏液腺内是黏液和线状细胞。

The mucus cells are packed with hundreds of vesicles of condensed mucus while each thread cell contains an intricately coiled protein fiber.

黏液细胞内有数百个凝结黏液的小泡，而每个线状细胞里都含有错综复杂的蛋白质纤维。