1a : the act or action of grasping with the intellect : understanding children who have difficulty with comprehension of spoken language What the artist actually needs is comprehension of his aims and ideals by men he respects â¦ â H. L. Menckenb : knowledge gained by comprehending tests that measure the students' comprehension in math She carried on ...
The inflammatory response (inflammation) occurs when tissues are injured by bacteria, trauma, toxins, heat, or any other cause. The damaged cells release chemicals including histamine, bradykinin, and prostaglandins. These chemicals cause blood vessels to leak fluid into the tissues, causing swelling.
UVB rays initiate DNA damage which leads to a series of biochemical and immunologic events that cause erythema and inflammation. Inflammatory mediators include prostaglandins, histamine, substance P, lipoxygenase products, cytokines, and adhesion molecules. Local cutaneous blood flow is increased by 2-3 times leading to erythema.