BIOL373 Lecture Notes - Lecture 6: Mast Cell, Vasoactivity, Degranulation
Document Summary
Innate response starts first and reinforced by more specific acquired response: 4 situations for body. Bacteria reach extracellular fluid due to failure of skin and mucus membrane. Cause inflammatory response that represents combined effects of many cells working to get rid of invader. If bacteria enter lymph, infection-fighting takes place in lymph nodes. Inflammation = red, swollen, warm area that is tender or painful. Entry of bacteria sets off several interrelated reactions: activity of the complement system. Some complement proteins = chemical signals (chemotaxins) that attract leukocytes from circulation to help fight infection. Causes degranulation of mast cells and basophils, causes release of cytokines by mast cells which attract more immune cells. Histamine = dilate blood vessels (vasoactive chemical), increase capillary permeability. Enhanced blood supply is what creates redness and warmth of inflammation. Swelling = occurs when plasma proteins escape into interstitial space and pull water with them.