University of Central Florida (UCF) PCB3233 Immunology Practice Exam 1

C5a is a potent anaphylatoxin, which is a small peptide that plays a crucial role in the inflammatory response. Its primary function involving mast cells is stimulating their activation, which leads to the release of various mediators, including histamine. When C5a binds to its receptors on mast cells, it triggers a signaling cascade that results in degranulation, causing the mast cells to release histamine and other inflammatory mediators.

Histamine is vital for various physiological processes, including vasodilation, increased vascular permeability, and attracting other immune cells to the site of inflammation. This response is essential for the body’s defense mechanisms against pathogens, but it can also contribute to allergic reactions and other hypersensitivity responses. Thus, the correct understanding of C5a’s role in stimulating the release of histamine helps clarify its importance in both normal immune function and pathophysiological conditions.