Ultrastructure of the horse tongue: further observations on the lingual integumentary architecture.

The research paper examines the unique structures on the surface of an adult horse tongue through various microscopic techniques. In particular, it details the distinctive characteristics of the cell structures and compositions of the tongue’s epidermal layer and papillae formations.

Microscopic Examination of Horse Tongue

• The study extensively used light, scanning, and transmission electron microscopy to closely observe the unique structures of the horse’s tongue.
• Samples were collected from seven distinct regions on the tongue of different horse breeds for the study.

Characteristics of Papillae

• The researchers found filiform papillae, small, slender, finger-like structures on the dorsal (top) and lateral (side) aspects of the tongue, but not on the ventral (bottom).
• The shape of these papillae terminae varied across the samples.
• On fungiform and vallate papillae, there was a reduction in the thickness of the epidermis (skin layer) and the height of the dermal ridges (skin texture).

Epidermal Analysis

• The tissue structure and keratinocyte ultrastructure (the cells which make up the outer layer of skin) of most of the tongue’s epidermis, correlated with the common mammalian epidermal model.

Unique Finding on Granular and Non-Granular Epidermal Cells

• One notable finding was a highly localized grouping of skin cells, containing a very high count of cytoplasmic granules known as trichohyalin.
• The granular cells were located on top of the dermal ridges and underneath the base of filiform papillae.
• Directly below these granular cells were clusters of clear, non-granulated skin cells.
• The researchers speculate that this unique cell composition might enhance structural strength at this particular site on the tongue in relation to increasing the tongue’s resistance to mechanical pressures from the papillae.