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

The study aimed to describe the ultrastructure of pig integument from 1 to 14 weeks and compare it to human integument. It found structural differences, such as a large bundle of smooth muscle fibers identified as interfollicular muscle, and nerve endings among these fibers. Nerves were frequently found around hair follicles, and intraepidermal nerve fibers were only seen at low resistance skin points. Basal cell projections increased slightly with age, and an unusual pericellular matrix was noted 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 humans, but Merkel cells were absent, and atypical Langerhans cells were present. Overall, the pig integument was similar to human integument, with no significant postnatal developmental changes observed.