Inflammation and Innate Immune Response - Anatomy and Physiology
- Which tissue cell is the main source of histamine released at a site of injury?
- Mast cells. Their granules release histamine, which dilates arterioles and makes capillaries leakier.
- What is margination during inflammation?
- The sticking of leukocytes to the inner lining of capillaries near the injury, mediated by adhesion molecules such as selectins.
- In innate defense, what does the term first line of defense refer to?
- Surface barriers, the skin and mucous membranes and their secretions, which block pathogen entry before inflammation is needed.
- Which vascular change produces the swelling of acute inflammation?
- Increased capillary permeability, which lets protein-rich fluid (exudate) leak into the tissue and cause edema.
- What are the four classic cardinal signs of acute inflammation?
- Redness, heat, swelling and pain (rubor, calor, tumor, dolor). Loss of function is often added as a fifth sign.
- What is pus?
- A mixture of dead and dying neutrophils, dead pathogens, tissue debris and fluid that collects at an infection site.
- What is chemotaxis?
- Movement of cells toward a chemical signal, such as neutrophils moving up a gradient of chemokines released at an injury site.
- Which innate lymphocyte kills virus-infected and cancer cells without prior sensitization?
- Natural killer (NK) cells. They release perforin and granzymes that trigger apoptosis of the target cell.
- Which vascular change produces the redness and heat of acute inflammation?
- Vasodilation of local arterioles, which increases blood flow to the injured area (hyperemia).
- Which white blood cell is usually the first to arrive in large numbers at a site of bacterial infection?
- Neutrophils. Monocytes arrive later and mature into macrophages.
- Which white blood cell type is most associated with defense against parasitic worms?
- Eosinophils. They release toxic granule proteins onto parasites too large to be phagocytized.
- What is diapedesis?
- The squeezing of leukocytes between endothelial cells of a capillary wall to leave the blood and enter the tissue.