Sweat is secreted by sweat glands of skin and helps in regulating body temperature. Saliva is secreted by salivary glands and helps in digestion (carbohydrate digestion). Sebum is the waxy secretion secreted by sebaceous glands. Sebum is a fatty mildly antiseptic material that protects, lubricates, and waterproofs the skin and hair and prevent desiccation. Humerus is the long bone of the upper arm. It articulates with the scapula at the glenoid cavity and with the ulna and radius at the elbow.