The openings of the glands are plugged with a solid, holocrine secretion that is removed when it moves through tunnels and leaves a secretion trail.
2.
Holocrine secretions are produced in the cytoplasm of the cell and released by the rupture of the plasma membrane, which destroys the cell and results in the secretion of the product into the lumen.
3.
Holocrine secretion is the most damaging ( to the cell itself and not to the host of which begot the cell ) type of secretion, with merocrine secretion being the least damaging and apocrine secretion falling in between.