Introduction to non-specific immunity Flashcards
What are the functions of the lymphatic system?
Draining interstitial fluid from tissue spaces
Transporting dietary lipids
Defence against disease
How is Lymph formed?
From blood plasma that filters from blood capillaries into interstitial space
Where does Excess interstitial fluid pass through?
Endothelium of lymph vessels into lymph capillaries
What are the Primary lymphatic organs?
Mature white blood cells called B and T lymphocytes, Red bone marrow and thymus gland
What are the secondary lymphatic organs?
Lymph nodes, spleen, lymph nodules
What are infections caused by?
Pathogens
Give me an example of a virus and bacteria infection?
Influenza virus, Clostridium tetani (tetanum)
Give me an example of a Protozoa, fungi and helminths infection?
Plasmodium (malaria)
Candida albicans (thrush)
tapeworms
What is the Innate immune system?
Non-specific, recognised molecules associated with pathogens, born with, respond immediately to pathogen
What is the Adaptive immune system?
Specific - for antigen and found in vertebraes acquired by experience and memory
Why is innate immunity important?
For initial immune response to a pathogen
What is Haemotopoiesis?
HSC sustain blood cells throughout life, capable of self renewal and multipotent
What is the Mechanism for non specific immune response?
Prevention of entry into the body and destruct foreign materials
What are the 3 non-specific defences?
Antimicrobial proteins
Natural killer cells and Phagocytes
Inflammation
What are the 3 Antimicrobial proteins?
Interferons
Compliment
Transferrins
What do Interferons IFNS do?
Produced by lymphocytes - function as chemical messengers instruct neighbour cells to produce antiviral proteins
What are the 3 types of Interferon proteins?
Alpha, Beta, Gamma
What do compliment proteins do?
Found in inactive state in blood plasma on membrane forms a complement system. when active enhance inflammatory reactions
What are transferrin proteins?
Iron binding proteins that inhibit growth of certain bacteria by reducing available iron
What are Natural Killer cells?
Specialised granular lymphocytes that are crucial for defence against tumour and viral cells, dont detect pathogen directly
How do NKs detect infected cells?
Defect effect on host cell and lack of host proteins or induction of stress proteins
What do Nks attack?
Abnormal cell membrane proteins called MHC antigens, destroy by releasing perforins or binding and inflict damage directly
What are phagocytes?
Engulfing cells and that can recognise microbes through specific receptors such as dendritic cells
What is Inflammation?
Defence response to damage with response such as redness,pain, heat and swelling
What are the functions of inflammation?
Traps invading microorganisms, allows region perfused with phagocytes and NK rich tissue fluids
What is the Process of Inflammation?
Non-specific and follow same path regardless of damage.
What are the 3 major phases of Inflammation?
Vasodilation and inreased permeability of blood vessels
Phagocyte migration
Tissue Repair
What is the Inflammatory response aided by?
Histamine, kinins, prostaglandings, leukotriens and complements
How does Histamine aid inflammation?
Released by mast cells in connective tissue and by basophils and plately. Histamines attracts neutrophils and macrophites to site of injury and induces vasodilation
How does Kinins aid Inflammation?
Formed from inactive precursor molecules called kininogens and induces vasodilation and promotes chemotaxis by phagocytes
How does Prostaglandins aid in inflammation?
PGS are lipids that are released by damaged cells, intensify effects of histamine and kinins and migrate phagocyte through capillary walls
How does Leukotriens aid inflammation?
Act as guidance for phagocytes and increase vasodilation and adherence of phagocytes to pathogens
How does Complement aid Inflammation?
Associate with release of histamine and attracts neutrophils for bacteria
What happens following an injury?
Arteries dilate and more permeable resulting in localised edema, erythema and increased temp
How is a scab formed?
Leakage of blood clotting factors into the injury
What is the process of cells migrating from bloodstream to affected tissue?
Diapedesis
What to WBCs enter wound site?
First neutrophils then monocytes
How is pus formed?
When macrophages die
How long does pus last?
Until infection is destroy and then drained or absorped
If pus does not drain what happens?
results in abscess or inflamed spot, if tissue sloughs away then forms ulcer
What is Ulceration a common feature in?
People with poor blood circulation i.e diabetics
What does fever do?
Increase body temperature with inflammatory response
Why does fever arise?
Bacterial toxins can elevate body temp by stimulating release of cytokines and interleukin-1
What does the release of Cytokines and Interleukin-1 do?
Hypothalmic set point elevates increased temp and inhibit replication of bacteria
What is the function of macrophages?
Role in homeostatis and tissue remodelling. ingest and process foreign material
What are scavenger receptors?
part of macrophage that recognise apoptopic and necrotic cells
What are Toll-like receptors?
Part of macrophage that recognise pathogens
What are Pattern recognition receptors?
part of macrophage that detect non-self damage
What macrophages express surface molecules?
CD11 B, CD68, CD18
What do M1 macrophages do?
Defend against bacteria and have anti-tumour activity
What do M2 macrophages do?
Anti-inflammatory action that regulate wound healing
What do regulatory macrophages do?
Secrete large amounts of IL-10
What do Myeloid suppressor (TAM) cells do?
Suppress anti-tumour immunity
