Non-Specific immune response Flashcards
What are the key features of a neutrophil?
-Lobed nucleus
-Completely destroy pathogen
-60% of WBCs
-Short-lived
What are the 3 stages of neutrophil action?
1.Phagocyte engulfs pathogen in phagosome
2.Phagosome+lysosome=phagolysosome. Lysosome contains hydrolytic enzymes to break down pathogen.
3.Waste materials released by exocytosis
What are the key features of a macrophage?
-Bean shaped nucleus
-Become antigen presenting cells
-4% of WBCs
-Long lived
What are the 4 steps in macrophage action?
- Phagocyte engulfs antigen in a phagosome
2.Phagosome+lysosome=phagolysosome, lysosome contains hydrolytic enzymes to break down pathogen
3.Antigen combines with MHC(self antigen) and is displayed on the cell surface
- Phagocyte becomes an antigen presenting cell.
It also interacts with T Helpers to convey ‘message to relevant specific immune system.
What is inflammation?
Localised response to pathogens resulting in pain, heat and swelling at site of infection. Happens because mast cells have released cytokines and histamines
What are mast cells?
White blood cells that release histamine and cytokines
What do histamines do?
-Makes blood vessels dilate, making them more leaky which forces out blood plasma(tissue fluid once exited)
-Causes localised heat which prevents pathogen reproduction
-Causes localised redness due to increased blood flow, more WBCs can reach area. Quicker response
What do cytokines do?
Attract WBCs(phagocytes) to the site. Dispose of pathogens by phagocytosis
Why are scabs formed?
Cuts mean skin barrier is breached, pathogens can enter. Platelets come into contact with collagen in skin and release thromboplastin and serotonin
What is thromboplastin?
An enzyme that triggers a cascade of reactions resulting in the formation of a blood clot
What is serotonin?
Makes smooth muscle in blood vessel contract to create a narrow blood vessel-> smaller blood supply to reduce blood loss
