Macroscopic and microscopic structure of the infraorbital sinus gland in Tuj Sheep

The infraorbital sinus (infraorbital gland-preorbital gland) is located in the lateral aspect of the skull, rostroventral to the eye, within the infraorbital fossa. Some skin glands are differentiated and specialized. In the present study, it was aimed to examine the macroscopic and microscopic structure of the infraorbital sinus, which is one of these skin glands. The distance between the infraorbital foramen and infraorbital sinus was 47.35± 0.57mm on the right and 53.80±1.27 mm on the left. The left side length of the infraorbital sinus in Tuj sheep was measured as 25.32±2.21 mm, width 16.21±2.83 mm, and depth 1.23±1.80 mm. The Tuj sheep infraorbital sinus was composed of the epidermis and dermis. The epidermis was consist of keratinized stratified squamous epithelium. There were many sebaceous glands, some apocrine glands, muscle fibers, and also hair follicles in the dermis. The sebaceous glands were located in the superficial region and the apocrine glands were deeper in the dermis. It was seen lots of lipid droplets inside the sebaceous gland cells. The myoepithelial cells and the basal membrane of the apocrine glands and muscle fibers were PAS-positive reaction. In conclusion, in the presented study, the macroscopic and microscopic structure of the infraorbital sinus was determined in Tuj sheep. This region is also clinically important because it is close to the infraorbital nerve passing through the infraorbital foramen (anesthesia area) and the infraorbital sinus is topographically located in this region. It is thought that it will support scientific studies related to the skin and its appendages.