IMMUNITY

IMMUNITY

1. INNATE IMMUNE RESPONSE

   • Rapid response to kill pathogens
   • Inflammation
     • Protective response
     • Destroy cause, remove, limit effects, replace tissue
   • Not long lasting
     • Primary outcome: destroy and remove
   • PHAGOCYTIC CELLS
     • MACROPHAGE
       • Large
         • Found throughout body
           • Amoeboid movement
             • Hunt and destroy antigen
       • Recruit other immune cells to site
     • NEUTROPHIL
       • Most abundant
       • Arrive first
       • Contain toxic substance
         • Kill or inhibit growth
           • Release cytokines
             • Amplify immune response
               • Recruit other cells to infection
     • DENDRITIC CELL
       • In tissue
         • In contact with external environment
           • e.g. skin, lungs
       • Messengers
         • between innate and adaptive
           • Presenting antigen material to T-cell
     • MAST CELL
       • Contain histamine
         • responsible for inflammation and allergic responses
       • Active: release histamine
         • Blood vessels dilate
           • Become leaky
             • Increased permeability
               • Allows phagocytes to each infection site
     • COMPLEMENT PROTEIN
       • Comprises number off diff proteins
         • Circulate as inactive precursors
           • Until activated
         • Phagocytosis
         • Attract macrophages and neutrophils to infection
         • Rupturing membranes of foreign cells

2. ADAPTIVE IMMUNE SYSTEM

   • Antigens presents on macrophage surface
     • e.g. cell walls of microbial cell
     • Activate cells against specific
   • Humoral Immune response
     • Serum (non-cellular part of blood
       • Antibodies secreted by B-cells
         • aka B lymphocytes
   • Cell-Mediated Response
     • Production of T-cells
       • aka specialised lymphocytes
       • Recognises by T-cell
         • Only after antigen processing
         • 1. engulfed by macrophge
           • Processes antigen
             • Prevents on surface
         • 2. helper T-cell recognises
           • Activate other cells
   • BONE MARROW: Cells mature
     • e.g. femur
       • Migrate from lymphatic organs
   • Stem cells
     • From bone marrow and fetal liver
       • Become B and T cells
   • B cell
     • Recognise and bind antigen
       • Helper T-cell recognise on its surface
         • Induce maturation and proliferation
     • May carry 100000 receptors
       • Defend against bacteria and toxins outside
     • MEMORY CELLS
       • Long-living
       • For when encountering antigen again
         • Rapidly change to antibody-producing cells
     • PLASMA CELLS

3. INFLAMMATORY RESPONSE

   • STAGES
     • 3. tissue repair
       • Functioning cells/support connective cells create new tissue
         • Some repair fast (skin)
           • Some repair slow (cardiac muscle)
     • 2. phagocyte migration and phagocytosis
       • After 1 hour
         • Phagocytes appear
           • Squeeze between cells of blood vessel wells
             • Reach area
               • Destroy invading microbes
     • 1. increased diameter and blood vessel permeability
       • Increase diameter and permeability
         • Increases blood flow
           • Allows defensive substance into tissue spaces