INTRO TO NON-SPECIFIC IMMUNITY Flashcards
what are the functions of the lymphatic system?
Draining excess interstitial fluid (Extracellular fluid) from the tissue spaces
Transporting dietary lipids and lipid soluble vitamins around the body
Defence against disease or Immunity
how is lymph formed?
formed from blood plasma that filters from the blood capillaries into the interstitial space
Excess interstitial fluid passes through the endothelium of the lymphatic vessels and enters the lymphatic capillaries. This fluid resembles blood plasma, but lacks the larger plasma proteins
what are the 2 groups lymphatic organs and tissues can be classified into?
the primary lymphatic organs
the secondary lymphatic organs and tissues
what are the primary lymphatic organs?
provide an environment in which mature white blood cells called the B and T lymphocytes can develop and mature
give examples of primary lymphatic organs
red bone marrow, and the thymus gland.
what are the secondary lymphatic organs and tissues?
majority of the immune response occurs
give examples of the secondary lymphatic organs and tissues
lymph nodes, the spleen and the lymphatic nodules
what is a pathogen?
the infectious agent
what is a host?
the organism that is infected
what are the 2 types of immune systems?
Innate (Non-specific)
Adaptive (Specific)
what is the innate immune system?
Recognises molecules commonly associated with pathogens
Represents the most of immunity
when does the innate immune system respond?
Is able to respond immediately to presence of pathogen, the first line of defence
does the response of the innate immune system change if the same pathogen is encountered?
Response is effectively identical each time the same pathogen is encountered
what is the adaptive immune system?
Is specific for an antigen
Only found in vertebrates
how is the adaptive immune system acquired?
by experience
what does the adaptive immune system do on the first exposure to the pathogen?
pathogen takes a number of days to respond, subsequent responses are greater in amplitude and more rapid: memory
what is the function of barriers?
Many barriers prevent pathogens from crossing epithelia and colonizing tissues or destroy them without distinguishing types
what is haemopoiesis?
h
what are haemopoetic stem cells?
h
what is the non-specific immune response?
mechanisms that protect from foreign substances in a non-specific way
what is the function of the non specific immune system?
Prevention of entry into the body
Destruction of foreign materials once they have entered the body by internal non-specific defences
give examples of non-specific defences
Antimicrobial proteins
Natural killer cells and phagocytes
Inflammation
what are the different antimicrobial proteins?
Interferons (IFNs)
Compliment
Transferrins
what are IFNs produced by?
lymphocytes, macrophages and fibroblasts that have been infected by viruses.
what is the function of IFNs?
act as chemical messengers instructing neighbouring cells to produce antiviral proteins that interfere with viral replication
what are the 3 types of IFNs?
the alpha, beta and gamma interferons
what are compliment?
a protein normally found in an inactive state in the blood plasma and on plasma memb, where it forms the complement system
what happens when compliment becomes activated?
enhance specific inflammatory reactions
what are transferrins?
iron binding proteins that inhibit the growth of certain bacteria by reducing available iron
what are natural killer cells?
specialized granular lymphocytes
why are NK cells important?
Crucial for defense against tumor and virally infected cells
what do NK cells detect?
Don’t tend to recognise pathogen directly, detect affects of the pathogen on the host cell
detect the lack of host proteins or the induction of stress proteins
what cell membrane proteins do natural killer cells attack?
histocompatibility complex (MHC) antigens
what happens when the natural killer cells attack?
NK cells destroy their targets by releasing perforins or by binding and inflicting damage directly