Page 95 - Atlas of Histology with Functional Correlations

membranes. Also present in the cytoplasm are free ribosomes (4, 13), some of

which attach to other ribosome and form ribosome groups called polyribosomes
(4, 13). Visible in the cytoplasm are also numerous mitochondria (2, 10), in
longitudinal (10) and cross section (2), dense secretory granules (8), and very
thin strands of microfilaments (5, 11). In the lower right corner of the

micrograph, the smooth cisternae and associated vesicles of the Golgi apparatus
(14) are visible. Note the cell membranes (1, 9) of adjacent cells, nuclear
envelope (6), and portions of the nucleus (7) and nuclear chromatin (12).

FIGURE 2.10 ■ Rough endoplasmic reticulum. ×32,000.

FIGURE 2.11 | Smooth Endoplasmic Reticulum

This high-magnification electron micrograph illustrates the structure of the
smooth endoplasmic reticulum (2) in two adjacent cells. Smooth endoplasmic
reticulum (2) is devoid of ribosomes and consists primarily of smooth,

anastomosing tubules. In this micrograph, the tubules of the smooth endoplasmic
reticulum (2) are primarily seen in cross section. In other sections, the smooth
endoplasmic reticulum (2) can be seen as flattened vesicles. In some cells,
smooth endoplasmic reticulum is continuous with cisternae of the rough

endoplasmic reticulum (7), as seen in this micrograph.

Also seen in the micrograph are the cell membranes (6, 11) of the two cells,
the cell membrane interdigitations (10), and the extracellular matrix (9)
between the two cell membranes. A section of the nucleus (4, 5), nuclear
envelope (8), nuclear chromatin (3), and mitochondrion (1) in cross section

are also visible in the two cells. The mitochondria (1) in these cells contain
tubular cristae, indicating that the cells synthesize products other than proteins.

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