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Slide #DMS 033 [Thick Skin, Primate]. Several neural elements may be seen including small nerve trunks and Meissner and Pacinian corpuscles.

This is a very low power view of a section through thick skin. The skin is replete with a variety of sensory nerve endings, two of which will be demonstrated in subsequent images: the Meissner's corpuscle, sensing fine, discriminative touch, may be found in the dermal papillae immediately beneath the epidermis; the much large Pacinian corpuscles, are found deep in the dermis or hypodermis, one being evident even at this low power.

Focusing in on the epidermis and superficial dermis, an examination of the dermal papillae (columns of dermis that extend up towards the epithelium) may reveal the Meissner's corpuscles as seen in the next image.

In this medium power image of the epidermis and superficial dermis, one may identify a Meissner's corpuscle in the dermal papillae, in close association with the overlying epidermal layer of cells. The distinctive morphology of this fine touch receptor is seen to better effect in the next image.

This high power view of a Meissner's corpuscle illustrates the 'coiled spring'-like morphology of this encapsulated sensory nerve ending. One or more axon endings would be found at the center of a surrounding sheath of supporting cells (modified Schwann cells and/or fibroblasts), the nuclei of which are apparent.

Even at this low power, the Pacinian corpuscle is a dominant element in the field. Designed to detect deep pressure and vibration, this encapsulated nerve ending has a very distinctive appearance, the details of which are more even more apparent in the next image.

This medium power view of a Pacinian corpuscle reveals the centrally-located unmyelinated axon (and associated Schwann cells) and the multiple layers of supporting cells (modified fibroblasts) forming an elaborate sheath, much like the multiple layers of an onion.

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