The mast cells create this reaction by releasing chemicals, called chemotactic factors, that then attract many other inflammatory cells to the site. These cells include: eosinophils, neutrophils, and lymphocytes. Once theyâve arrived, each one of these cells contributes to the late phase of the allergic response. Eosinophils generate chemicals similar to those made by mast cells, as well as release more generally toxic substances that irritate the body.
20 Important Characteristics of Urban Community | Sociology. A sociological analysis of urban community contains several salient features. As a rule, in the same country and at the same period, the size of an urban community is much larger than that of a rural community. In other words, urbanity and size of a community are positively correlated. Image Courtesy : upload.wikimedia.org/wikipedia/commons/0/08/Ginza_area_at_Tower.jpg.
There are three classes of urban area: main urban areas are the 17 urban areas which have a population of 30,000 or more; secondary urban areas are the 14 urban areas which have a population of 10,000 or more but less than 30,000, and minor urban areas are the 103 urban areas which have a population of 1,000 or more but less than 10,000.