Page 177 - Atlas of Histology with Functional Correlations

FIGURE 5.5 ■ Embryonic connective tissue. Stain: hematoxylin and eosin. Left,

low magnification; right, high magnification.

FIGURE 5.6 | Loose Connective Tissue

Collagen fibers (9) predominate in loose connective tissue, course in different

directions, and form a loose fiber meshwork. Surrounding the connective tissue
fibers and cells are clear spaces of the ground substance. In the illustration,
collagen fibers (9) are sectioned in various planes, and transverse ends may be
seen. The fibers are acidophilic and stain pink with eosin. Thin elastic fibers are

also present in loose connective tissue but are difficult to distinguish with this
stain and at this magnification.

The fibroblasts (2) are the most numerous cells in the loose connective
tissue and may be sectioned in various planes, so that only parts of the cells may
be seen. Also, during section preparation, the cytoplasm of these cells may

shrink. A typical fibroblast (2) shows an oval nucleus with sparse chromatin and
lightly acidophilic cytoplasm, with a few short processes.

Also present in loose connective tissue are blood cells such as the
neutrophils (6) with lobulated nuclei, eosinophils (3) with red-staining

granules, and small lymphocytes (7) with dense-staining nuclei and sparse
cytoplasm. The fat (adipose) cells (5) appear characteristically empty with a thin
rim of cytoplasm and peripherally displaced flat nuclei (4).

The loose connective tissue is also highly vascular; capillaries (8) sectioned
in different planes (t.s., transverse section; l.s., longitudinal section) are visible.

A larger arteriole (1) with RBCs is also seen.

FIGURE 5.6 ■ Loose connective tissue with blood vessels and adipose cells.
Stain: hematoxylin and eosin. High magnification.

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