Immune System

Question 1

what does the immune system do

Answer 1

recognise and kill infected cells

Question 2

types of WBC

Answer 2

granulocytes (neutrophils, eosinophils, basophils), lymphocytes (T cells, B cells, natural killer cells)

Question 3

what is inflammation

Answer 3

response of the immune system to pathogens in the body

Question 4

how does inflammation present

Answer 4

heat, swelling, redness, pain

Question 5

what causes inflammation

Answer 5

any form of tissue damage stimulates inflammatory response. can be caused by extremes of temperature, presence of foreign bodies, trauma, corrosive chemicals, abrasion, autoimmunity, infection

Question 6

effects of inflammation on the body

Answer 6

• increased blood flow to inflamed area caused by vasodilation
• increase in permeability of capillary membrane means fluid goes from capillary to to interstitial space
• this causes swelling
• plasma proteins inc. fibrinogen leak into interstitial spaces from capillary membrane
• increased fibrinogen causes increase in clotting factor in interstitial space
• lymphocytes perform function of acquired immunity
• walling off- inflamed tissue is separated from other tissues because fibrin clots around affected tissue
• tissue macrophage moves to area and begins to attack pathogen
• neutrophils in blood stream are recruited to inflamed site to continue process of fighting pathogens
• increased production of granulocytes and monocytes by the bone marrow
• formation of pus

Question 7

types of t lymphocytes

Answer 7

helper t cells, killer t cells, suppressor t cells, memory t cells

Question 8

activation of t lymphocytes

Answer 8

• macrophages present bacteria to lymphocyte
• this activates t lymphocyte to begin its function
• t lymphocytes respond to antigens only when they bind to MHC proteins on the surface of antigen-presenting cells
• MHC proteins are encoded by a large group of genes called the major histocompatibility complex
• MHC 1 proteins present antigens to killer t cells, MHC 2 proteins present antigens to helper t cells

Question 9

helper t cells function

Answer 9

production of cytokines, stimulation of growth and proliferation of killer and suppressor t cells, stimulation of b cell growth and differentiation to form plasma cells and antibodies

Question 10

killer t cell functions

Answer 10

directly inactivate any cells carrying antigens
attach themselves to the target cell and release perforins

Question 11

suppressor t cell functions

Answer 11

suppresses function of other t cells so body does not attack its own cells

Question 12

memory t cell functions

Answer 12

recognises an antigen when exposed to it again to produce a faster immune response

Question 13

b lymphocyte function

Answer 13

produce antibodies

Question 14

what is type 1 hypersensitivity

Answer 14

allergic reaction, anaphylaxis

Question 15

how does type 1 hypersensitivity present

Answer 15

hay fever, asthma, hives, eczema, full anaphylaxis

Question 16

causes of type 1 hypersensitivity

Answer 16

sensitivity to allergen

Question 17

effects of type 1 hypersensitivity on the body

Answer 17

• provoked by re-exposure to a specific type of antigen
• immune mechanism- mediated by IgE antibodies bound to Fc receptors on mast cells
• immune system sees the antigen as harmful/toxic which causes allergic reaction
• secretion of IgE antibodies by plasma cells
• IgE bind to tissue surface receptors on mast cells and basophils, causing them to be sensitised
• later exposure to the same antigen cross-links the bound IgE on sensitised cells
• this produces degranulation and the production of allergic mediators
• this causes inflammation and swelling
• histamine causes vasodilation
• swelling
• immunoglobulin sensitised
• mast cells release histamine