Page 484 - Atlas of Histology with Functional Correlations

A low-power photomicrograph illustrates the superficial and deep structures in

the thick skin of the palm. The cell layers in the epidermis are (6) stratum
corneum (7), stratum granulosum (8), and stratum basale (9). Inferior to the
epidermis (6) is the dense irregular connective tissue dermis (5). Dermal papillae
(11) from the dermis (5) indent the base of the epidermis (6). Deep in the dermis
(5) and the hypodermis (4) are cross sections of the coiled simple tubular sweat

glands (3) and their excretory ducts (10). A layer of adipose tissue (1) deep to
the dermis (5) is the hypodermis (4) or the superficial fascia. The hypodermis (4)
is not part of the integument. Two sensory receptors called the Pacinian

corpuscles (2) are seen inferior to the adipose tissue (1) of the hypodermis (4).

FIGURE 12.7 ■ Thick skin: epidermis, dermis, and hypodermis of the palm.
Stain: hematoxylin and eosin. ×17.

FIGURE 12.8 | Thick Skin of Palm, Superficial

Cell Layers, and Melanin Pigment

Thick skin is best illustrated by examining a section from the palm. The
epidermis of thick skin exhibits five cell layers and is thicker than thin skin (see
Figs. 12.2 to 12.4). The different cell layers of the epidermis are illustrated
below in greater detail and at higher magnification.

The outermost layer of thick skin is the stratum corneum (1, 9), a wide
layer of flattened, dead, or keratinized cells that are constantly shed, or
desquamated (8), from the skin surface. Inferior to the stratum corneum (1, 9) is
a narrow, lightly stained stratum lucidum (2) that is difficult to see in most

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