Immune Response To Parasites Flashcards
what are the two types of first line defence
physical barriers, chemical secretion
give an example of a physical barrier first line response
skin, nasal hairs
what are tears an example of
chemical secretion first line defence
what do tears contain that make them suitable for first line defence
antibodies and lysozome enzymes
give an example of chemical secretion as part of first line defence
acid secretion, tears, mucus
when is the second line of defence triggered
after parasite enters body fluids
what are the three second line responses
inflammatory response, phagocytes , natural killer cells
what happens in a inflammatory response
injured/infected cells release histamine , causing local blood vessels to dilate, increasing blood flow to that area causing redness and warmth. blood vessels become more permeable and pain is triggered by pressure on nerve endings
what are phagocytes
white blood cells that migrate out of the blood and surround, engulf and digest viruses
what are natural killer cells
types of white blood cells that detect abnormal cell surface proteins located on virus infected and cancerous cells
what do natural killer cells trigger
apoptosis
what is apoptois
programmed cell death
what are the two specific immune responses to parasites
immune surveillance and lymphocytes
what is a clone
a group of about 1000 identical cells made from a common ancestor cell, with just one type of receptor
what are the two types of lymphocytes
T lymphocytes and B lymphocytes
what are the two roles of t lymphocytes
- stimulate other t lymphocytes and cause b lymphocytes to divide rapidly, - destroy infected cells by triggering apoptosis
describe what t lymphocytes do in the immune response to parasites
wait for a phagocyte to become a presenting cell and if they have correct surface receptor they will bind to surface antigens and become activated
what happens to T lymphocytes after the pathogen is destroyed
some will remain in circulation as memory cells
what is the difference in B lymphocytes compared to T lymphocytes
b lymphocytes can bind directly to antigens
what is the role of b lymphocytes
produce antibodies and allow phagocytes to engulf and digest them
when does clonal selection occur
when antigen receptor protein binds to a specific antigen
what is clonal selection
the activation of a lymphocyte leading to many lymphocytes being made and ready to rapidly divide
what is immune surveillance
lymphocytes circulate around body checking for antigens that are non self
what is a benefit of immunological memory
produce quicker and more efficient response if parasite returns
