When someone becomes excited, their pupils can dilate to up to four times their original size. Conversely, an angry, negative mood causes the pupils to contract to what are commonly known as 'beady little eyes' or 'snake eyes'. Lighter eyes can look more attractive because it's easier to see the dilation taking place.
The term papilla (plural: papillae) generally means a nipple-like structure, and may refer to: Mammary papilla, or nipple. Amphibian papilla and basal papilla, part of the inner ear of the frog. Interdental papilla, part of the gingiva between teeth.
In the human skin, the dermal papillae (DP) (singular papilla, diminutive of Latin papula, 'pimple') are small, nipple-like extensions (or interdigitations) of the dermis into the epidermis.At the surface of the skin in hands and feet, they appear as epidermal or papillary ridges (colloquially known as fingerprints).Blood vessels in the dermal papillae nourish all hair follicles and bring nutrients and oxygen to the lower layers of epidermal cells.The pattern of ridges they produce in hands and feet are partly genetically determined features that develop before birth.ermal papillae also play a pivotal role in hair formation, growth and cycling. In mucous membranes, the equivalent structures to dermal papillae are generally termed connective tissue papillae, which interdigitate with the rete pegs of the superficial epithelium.