Gross And Histological Studies on the Interdigital Sinus of Nellore Sheep

Abstract

The study was carried out on six Nellore sheep and the samples were collected from local slaughter house. The interdigital sinus of sheep was located in the space between the two digits and its opening was present anteriorly just above the interdigital cleft. Morphologically it was “V†shaped and consisted of three parts: fundus, corpus and collum. The lumen of the gland was filled with a dense secretary material and wool fibers. Histologically the interdigital sinus consisted of three layers: epidermis, dermis and fibrous connective tissue capsule within outwards. In the body or
corpus region epidermis was folded into the lumen and was lined by stratified squamous keratinized epithelium with
desquamated cells of epithelium towards adluminal surface, whereas in the collum or neck region keratinization was
more. The dermis was made of dense irregular connective tissue and it consisted of hair follicles, arrector pili muscles,
sebaceous glands and apocrine sweat glands. Sebaceous glands were closer to the lumen in the corpus, whereas in the
neck region large sebaceous glands and hair follicles were appeared close to the capsule. Sweat glands were appeared as
compound tubular glands varied in size and shape in the corpus, however in neck region the sweat glands were few in
number and smaller in size. Each sweat gland was surrounded by circularly arranged collagen fibers and myoepithelial
cells. The sweat glands were lined by simple columnar to high cuboidal epithelium, whereas the excretory ducts were
lined by bilayered cuboidal epithelium.