An Ultrastructural Postnatal Developmental Study of the Integument of the Pig (Sus Scrofa)

This study examined the ultrastructure of pig integument from 1 to 14 weeks of age, focusing on comparisons with human skin. Key findings included the presence of a large interfollicular muscle, nerve endings among muscle fibers, and autonomic innervation suggested by vesicles in subepidermal nerve endings. Basal cell projections increased slightly with age, and a unique pericellular matrix was observed in mast cells. A structure resembling a large Meissner's corpuscle was found in the lumbar region. Apocrine sweat glands and ducts were similar to those in humans, while atypical Langerhans cells were present without characteristic granules. Overall, pig integument was similar to human integument, with no significant postnatal developmental changes observed.