| Comments |
p.269 left column top paragraph:"These micrographs illustrate the main ultrastructural features of enterocytes, the absorptive cells of the small intestine. Micrograph (a) shows the enormous number of microvilli Mv (up to 3000 per cell), which increase the surface area of the plasma membrane exposed to the lumen by some 30 times. The microvilli are of uniform length (approximately 1 µm) and constitute the brush border of light microscopy (see Figs 14.22 and 5.14). Most absorption in the small intestine occurs by direct passage of low molecular weight digestion products across the luminal plasma membrane." |