ABSTRACT
The pig is a relatively hairless animal with a xed skin tightly attached to the subcutaneous tissues similar to that in humans. The cutaneous blood supply and sequence of events in wound healing are also similar to that in humans. However, the skin of the pig is thicker and less vascular overall than human skin. The thickness of the skin is especially pronounced in sexually mature animals on the dorsal surface of the neck and back and in some breeds such as the Yucatan. There are also differences in the accessory tissues, such as the variations in sweat glands and the presence of an intrafollicular muscle in swine (Figures 3.1 and 3.2). Pigs have sebaceous glands, which are relatively insignicant. There is a variation from humans in the number and function of the apocrine and eccrine sweat glands. Eccrine glands in pigs are limited to the snout and carpal glands, whereas in humans they are extensive and active in the sweating phenomenon. Apocrine sweat glands are more extensive in pigs but, as in humans, do not contribute to sweating or thermoregulatory functions to a high degree. Secretions on the skin may help to prevent uid loss, but pigs in outdoors subjected to high temperatures thermoregulate by wallowing or seeking shade rather than actively sweating. There is a mental gland between the mandibles that contains tactile hairs and provides sebaceous and apocrine secretory functions (Argenzio and Monteiro-Riviere, 2001; Monteiro-Riviere, 1986, 2001). Colored histologic sections are located on the textbook DVD.
