Page 179 - Atlas of Histology with Functional Correlations

presence of collagen fibers replaces the loose type.

The collagen fibers (2, 9) in both types of tissues are large, typically in

bundles, and sectioned in several planes because they course in various
directions. Also visible are thin, wavy elastic fibers that form fine networks.
However, these fibers are not obvious in routine histologic preparations.

In the dense connective tissue (1), the fibroblasts (nuclei) (3) are often
found compressed among the collagen fibers (2). In the loose connective tissue

(5), the collagen fibers (9) are less compressed and the fibroblasts (10) are more
visible. Also illustrated are capillaries (4), a small venule (11), an eosinophil
(6) with lobulated nucleus, lymphocytes (7) with large round nuclei without

visible cytoplasm, a plasma cell (8), and numerous adipose cells (12).

FIGURE 5.8 ■ Dense irregular and loose irregular connective tissue. Stain:
hematoxylin and eosin. High magnification.

FIGURE 5.9 | Dense Irregular Connective Tissue

and Adipose Tissue

This photomicrograph illustrates a deeper section of the skin called the dermis.
This region contains dense irregular connective tissue (1) and the collagen-
producing fibroblasts (3). Here, the collagen fibers (2) show a very random and
irregular orientation. Adjacent to the dense irregular connective tissue (1) is

adipose tissue (4) with its numerous adipose cells (5). Tissue preparation
dissolves the lipids in individual adipose cells, and cell cytoplasm appears empty
with only flattened, dense-staining nuclei in the peripheries. Dermis of the skin
also contains numerous sweat glands. The light-staining regions are the

secretory cells of the sweat gland (7), whereas the dark-staining cells form the

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