Skin sweat glands. Polarised light micrograph of a transverse section through skin from a human foot. The epidermis (yellow) consists of dead keratinised cells. Below this are the ducts of the sweat glands. The sweat glands (bluishblack, across bottom) are found in the dermis (the skin layer below the epidermis) as balls of twisted glandular tubes, which unite to form the sweat ducts (darkblue) that secrete sweat through the pores in the epidermis. The other structures in the dermis are either only partially seen, or not visible in polarised light. Magnification: x36 when printed at 10 centimetres across.