4.1. The Non-specific Immune System Flashcards
What are the functions of the non- specific immune system?
- Providing a physical barrier.
- Producing secretions.
- Releasing cytokines.
- Phagocytosis.
- The Inflammatory response.
- NK Cell action.
What is epithelium?
Either a simple or complex covering for underlying tissue.
Simple e.g. lining of the bladder.
Complex e.g. ciliated epithelium on the inner lining of breathing tubes. Mucus is secreted here and the cilia sweeps mucus with trapped foreign particles away from the lungs.
What is secretion in terms of the non-specific immune system?
Epithelium glands such as the gastric glands in the stomach secrete mucus and acid. The mucus protects the epithelium from the acid, digestive enzymes and bacteria.
What are cytokines?
Small proteins that are important in cell signalling. They are secreted by a range of immune system cells and affect other cells in regards to how they respond to infection. Cytokine signals result in the accumulation of phagocytes and antimicrobial proteins are delivered as well. Clotting elements are released too.
What is the process of phagocytosis?
Antigens on the surface of a pathogen are detected by the phagocyte. The phagocyte then completely engulfs the pathogen into a vesicles. Lysosomes then fuse with the vesicle and release digestive enzymes to destroy the pathogen. The digested products diffuse into the cytoplasm and provide nutrition.
What is inflammation?
Changes that protect infected tissue.
When tissue becomes infected mast cells release histamine and other immune system cells release cytokines. Histamine causes capillaries neat infected area to dilate and become more permeable. Phagocytes, clotting elements and antimicrobial proteins are brought by the cytokines and accumulate at the infected area. Phagocytes start to destroy pathogens through phagocytosis and phagocytes then release cytokines which triggers a specific immune response.
What is natural killer cell action?
NK cells are white blood cells that induce cells that have been invaded by viruses to produce self-destruct enzymes in a process known as apoptosis. Viral reproduction is then prevented and recovery becomes easier.
