The immune system Flashcards
Name the components of each layer of centrifuged blood
Upper(“straw-coloured”) - plasma(90% water, electrolytes, proteins, lipids, sugars etc)
Middle(“white fluffy” buffy coat) - WBCs
Lower - RBCs, platelets
What is the scientific name for white blood cells?
Leukocytes
What is the scientific name for red blood cells?
Erythrocytes
What is the scientific name for platelets?
Thrombocytes
What cells does the common lymphoid progenitor give rise to?
B lymphocytes, T lymphocytes, Natural Killer cells
What cells does the common myeloid progenitor give rise to?
Megakaryocytes, erythrocytes(RBCs), myeloblasts, mast cells
What cells does the myoblast give rise to?
Basophils, neutrophils, eosinophils, monocytes
What cells does the monocyte give rise to?
Macrophages and dendritic cells
What do megakaryocytes give rise to?
Thrombocytes (platelets)
Where are most leukocytes made?
Bone marrow (except T lymphocytes)
Where are T lymphocytes made?
The thymus
What is the name of the stem cell which gives rise to blood cells?
Multipotent haematopoietic stem cell (Or haemocytoblast)
Name the polymorphonuclear lymphocytes
Neutrophils, eosinophils, basophils, mast cells(?)
Name the mononuclear leukocytes
T cells, B cells, monocytes, dendritic cells, natural killer cells
What are the soluble factors of the immune system?
Complement, antibodies, cytokines, chemokines
What secretes the complement proteins?
The liver
Name the 3 complement activation pathways and what they are
Classical - antibody binds to microbe
Alternative - complement binds to microbe
Lectin - mannose binding lectin (MBL) binds to microbe
In infection, what are the modes of action of complement?
Direct lysis of microbes, attracting more leukocytes to infection site (chemotaxis), coating invading organisms (opsonisation)
Which immunoglobulin is most abundant?
IgG
Which immunoglobulin is a pentamer?
IgM
Which immunoglobulins are monomers?
IgG, mIgM, IgA (not all), mIgD, IgE
Where is IgM mainly found and why?
In the blood becasue it is too large to cross the endothelium
Where are there high concentrations of IgA and what is it called there?
Mucous secretions (e.g. saliva, milk, bronchiolar and GU secretions). Secretory IgA (sIgA)
What is the least abundant immunoglobulin?
IgE
What cells have IgE-specific receptors and readily bind to IgE?
Basophils and mast cells
What responses is IgE mostly associated with?
Hypersensitivity allergic responses and parasitic infections
Name the 4 types of cytokine
Interferons (IFN), interleukons (IL), colony stimulating factors, tumour necrosis factors (TNF)
What do interferons do?
Induce a state of antiviral resistance in uninfected cells and limit the spread of viral infection
What do interleukins do?
Cause cells to divide, differentiate and secrete factors
What do colony stimulating factors do?
They are involved in directing the division and differentiation on bone marrow stem cells
What do tumour necrosis factors do?
Mediate inflammation and cytotoxic reactions
Give key features of innate immunity
Non-specific, doesn’t depend on recognition by lymphocytes, instinctive, slow, present frfom birth
What 3 parts make up innate immunity?
Physical and chemical barriers, phagocytotic cells, blood proteins
Give key features of adaptive immunity
Responds to specific antigens, faster acting, forms memory to specific antigens, ‘learned’ immunity
What is the difference between cell mediated and humoral immunity?
Cell mediated involves T cells to kill intracellular microbes, humoral involves B cells (plasma) producing antibodies to kill extracellular microbes
Why are cells that recognise ‘self’ killed as they mature?
To prevent the immune system from attacking the body’s own healthy tissues (autoimmune response)
Innate immunity definition
An instinctive, non-specific protection from pathogens that is present from birth
Adaptive immunity definition
A specific, acquired immunity that requires lymphocytes and antibodies
Haematocrit definition
The ratio of red blood cells to total volume of blood
Serum definition
Plasma without fibrinogen and other clotting factors
Antibody/immunoglobulin definition
A glycoprotein in the blood produced in response to a specific antigen
Cytokines definition
A number of proteins secreated by immune and non-immune cells that are important in cell signalling
Chemokines definition
(Chemotactic cytokines) A small group of cytokines which can induce directed chemotaxis in nearby responsive cells
