Explanation: The immune system's way of protection initially begins using the skin to protect against any physical and chemical harm. This is called the first line of defense. Amongst other first line defense mechanism includes; tears to protect from harmful substance in dust and air, cillia inside the nose, the internal mucosal linings to protect against harsh chemicals as well as freindly bacteria called our normal microflora.
A dermatome represents the unilateral area of skin on the body that is innervated by fibers from the sensory portion of a single spinal nerve coming from the spinal cord. Each spinal nerve contains spinal roots (anterior and posterior) that come together to form the spinal nerve.
