Carlton, a 6-year-old boy, was playing on a sandy beach with his mother. He began to run along the shoreline when he stepped on
the sharp edge of a shell, giving himself a deep cut on his foot. His mother washed his foot in the lake and put on his running shoe to take him home. One day later, Carlton’s foot looked worse. The gash was red and painful. The foot was warm to touch and appeared swollen. Carlton’s mom put some gauze over the wound and prepared to take him to the local community health clinic. A. What is the physiologic mechanism causing the wound to become red, hot, swollen, and painful?
B. How is this different than the inflammatory response that might occur in an internal organ?
C. What are the immunologic events that are happening at the local level during Carlton’s acute inflammatory response?
A skin infection occurs when there are too many germs for the white blood cells to fight and kill. The WBCs begin to expel chemicals into the wound site and this causes the redness and warmth in that area. The chemicals also cause fluid [plasma] leakage from the blood which causes swelling in that area. The swelling may stimulate the nerves which accounts for the pain.
* Inflammatory response in internal organs occurs when the damaged cells begin to release chemicals like histamine, bradykinin and prostaglandins. These chemicals cause blood vessels to leak, releasing plasma into the tissue and causing swelling in that area.
* The platelets in the blood cell are activated to stop the bleeding from the cut. The platelets also secrete chemicals called cytokines into the blood to start the healing process. They also alert the immune system which release several immune cells which begin scanning for germs in the blood. The macrophages start destroying the germs and disposing off the dead body cells. The T-cells and B- cells receive the signals from dendritic cells, which are activated by the macrophages. The T-cells and B-cells come into action and help the body fight off the germs.
At the site of the injury, swelling occurs due to concentration of different cells and tissue fluids in the area
