As degranulation occurs, it causes the mast cell or basophil to release a series of chemicals that orchestrate the allergic reaction. Within every mast cell or basophil are 500 to 1500 granules containing more than thirty different allergy-causing chemicals.
Urban design is an inter-disciplinary subject that unites all the built environment professions, including urban planning, landscape architecture, architecture, civil and municipal engineering.
In these studies, urban morphology is defined in terms of a concern with studying the material built form of urban landscapes and identifying different types of urban landscape based upon their morphological characteristics, as well as explaining variations in urban form through historical processes and social agency.