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→Skin of the legs and feet
====Skin of the legs and feet====
====Skin of the legs and feet====
*'''Podotheca''' - the non-feathered areas of the legs and feet. Scales are formed from raised, heavily keratinised epidermis separated by folds of less keratinised tissue overlying a proliferative germinal layer, giving it a 'pimpled' architecture.
*'''Podotheca''' - the non-feathered areas of the legs and feet. Scales are formed from raised, heavily keratinised epidermis separated by folds of less keratinised tissue overlying a proliferative germinal layer, giving it a 'pimpled' architecture.
====Glandular tissue====
The avian skin is effectively glandless, lacking sebaceous and sweat glands and most of the skin is thin, dry and inelastic. The exceptions are:
* Uropygial gland
* Glands of the ear canal
* Pericloacal glands
The '''Uropygial gland''' is also known as the ''preen gland''. It is a bilobed gland located dorsal to the cloaca at the end of the pygostyle. It opens through a caudally directed nipple.
This ''holocrine'' gland is NOT present in all species of bird. It is well developed in some parrots (African Greys) but absent in others (Amazons). It is also present in most finches but only some ''columbiformes''.
The uropygial gland is involved in maintaining feather condition and secretions spread by preening. It serves a waterproofing function. The secretions contain a pro-vitamin D, converted by UV light to active vitamin D. The secretions are also believed to suppress the growth of micro-organisms, serving an anti-bacterial function.
==Links==
==Links==
http://en.wikipedia.org/wiki/Feathers
http://en.wikipedia.org/wiki/Feathers