What is this carpet made of? These fibers or fingerlike extensions of the
plasma membrane are microvilli. Do not mistake them for cilia: cilia possess
10 pairs of microtubules (one central pair surrounded by the 9 others)
that run throughout their length. Microvilli do not. 1: Microvilli In the longitudinal section
at low magnification, observe the microvilli (1) on the top of the cells of the
ABO. On this photomicrograph, you only see the
apical part of the epithelial cells of the ABO (d).
If you increase the magnification
you can see (in c) the continuity between the
microvilli (1) and the cytoplasm of the cell it belongs to (b).
You do not see the 9+1 pattern
of microtubules in the
cross section of these fingerlike extensions.
You just see cytoplasm (e).
e: Cytoplasm inside the microvilli
f: Plasma membrane
Notice the dilations (1a) along the length of these microvilli.
This is very unusual: as a general rule, microvilli do not possess such things.