Sweat gland. Fluorescent deconvolution light micrograph of a section through a dermal duct from a sweat gland, showing beta defensin peptides (red). Sweat glands are a form of eccrine gland, which are composed of an intraepidermal spiral duct, the 'acrosyringium'; a dermal duct, comprising a straight and coiled portion; and a secretory tubule, coiled deep in the dermis or hypodermis. Beta defensins are antimicrobial peptides, part of the innate immune response. Magnification: x400, when printed 10 cm wide.