21) Fill in the missing information in this description of inflammation. (10)
• A pathogen gains entry through the body surface by evading ____ barriers
such as the multiple layers of dead skin in the epidermis and by evading antimicrobial
peptides made by the ____ microbes on the skin.
• Resident immune cells recognize the pathogen's presence and release inflammatory
mediators. Mast cells and basophils release _____, which increases blood flow
to the area by inducing blood vessels to vaso____ (constrict/dilate).
• Three examples of chemoattractants, which attract immune cells to the area, are: a)
breakdown products from phagocytosis, b) the cytokine _____, and c) the
complement protein _____.
• Once nearby blood vessels have become permeable, neutrophils (and other WBC's) gain
access to the tissue through the four-step process called _____.
? Step 1: The neutrophil rolls along the endothelium surface, where the L-selectin on
the neutrophil's surface interacts with the _____ protein on the
endothelial cell's surface.
? Step 2: Transmembrane proteins on the neutrophil, called _____
(give general group name or one example) change conformation and become capable
of binding the ICAM-1 on the endothelium, arresting the movement of the neutrophil.
? Step 3: In arrest/adherence, the neutrophil flattens and crawls along the endothelium.
? Step 4: In the process termed _____, the neutrophil pulls itself
through gaps between endothelial cells, using tight junction proteins as anchors.
