Epithelial

Lip

This demonstrates stratified squamous epithelium of both keratinized(skin aspect) and non-keratinized(oral aspect) types. On the skin side, the keratin layer appears detached. Examine the epithelium on both sides at higher magnification. Note that the cells are more flattened in the superficial layers. Why? On the outer aspect(skin) of the lip, you may find some hair follicles with associated sebaceous gland(holocrine secretion). Move your field now to the deeper zone of the lip. Can you identify any mucous acini? Draw a mucous acini. How does it differ from a serous acini?