WHOLE MOUNTS FOR THE STUDY OF SKIN AND ITS APPENDAGES

[摘要] A study of the micro-anatomy of the skin is facilitated by the use of cleared unfixed whole mounts. Fixation artifacts are minimized and an opportunity is provided to visualize the morphology of intact epidermis and appendages in toto. For observation of fine structure it is desirable to remove the connective tissue from the epidermis. A variety of techniques and substances for this purpose were investigated. Optimum results were obtained with 0.1% collagenase or 2N sodium iodide. Examination of fresh, separated epidermis with darkfield illumination, polarized light, and transmitted light as well as following treatment of the tissues with modifications of standard histo-chemical procedures provided useful morphologic and chemical information. Such preparations permit excellent and comprehensive visualization of the epidermal pattern, not only the surface ridges and furrows but also the underlying anastomosing rete pattern, and the relationship of the appendages to the epidermis. When the pilosebaceous apparatus is viewed as a whole, the structure, size and potential clinical importance of the keratinized infundibulum, as well as other morphologic features such as size and relationships of the sebaceous glands become apparent. Presence of a discrete epidermal eccrine sweat duct unit was confirmed. The details of its fine structure were described including the beaker or surface receptacle, the distal, coiled, keratinized cellular and the proximal, coiled, nucleated cellular parts of the duct. The Hotchkiss-McManus positive cuticle of the sweat duct was traced as a continuous lining of the straight dermal and the coiled epidermal parts of the duct up to the level of the keratinized part of the duct.