You can see the fingerlike extensions of the
plasma membrane: the microvilli (1)
and secretory
products (3). The blobs are secretions
coming out
of the apex (=top) of the cells. Notice the cytoplasm of the cell (b).
Decrease the magnification.
Only the apical part (d) of the ABO cells is shown here. On the
SEM photomicrograph,
you can see different stages of secretion:
It seems that these ABO cells
accumulate their secretions (whatever they are)
beneath their apical membrane. Then the apex
of the cells pinches off and the secretions enclosed in
the plasma membrane (which looks like a blob).
are released on the outside.
- accumulation of the products of
secretion under the apical membrane (=formation of the blob) (3)
- release of the secretions (blob disappears)(A,B,C).