BI SC 004 Lecture Notes - Lecture 40: Leukocyte Extravasation, Mast Cell, Connective Tissue
Document Summary
The first line of defense: physical barriers, chemical barriers, lysozyme found in, saliva, tears, sweat, acidic ph of the, stomach, vagina. Neutrophils: about 50 70% of all wbcs, have a multi-lobed nucleus, upon infection, move out of circulation into tissues, engulf pathogens, this happens through phagocytosis. Monocytes & macrophages: relatively uncommon wbcs, largest wbc, with horseshoe-shaped nucleus, take residence in tissues, develop into macrophages, macrophages engulf pathogens, use phagocytosis for this. The second line of defense: phagocytic white blood cells. Includes: neutrophils, macrophages, both, leave circulation, move into tissue. Blood cells enter and leave circulation through diapedesis: connective tissue, blood capillary, white blood cell. The second line of defense: inflammatory response: four hallmark symptoms, redness, heat, swelling, pain, histamine, released by mast cells, causes the capillaries to dilate, become more permeable to phagocytic white blood cells. Increased blood flow to an area increases warmth.
