General Principles Flashcards
The only source of vitamin B12 for humans is _______________________
animal-based foods (such as steak, fish, crabs, oysters, milk and cheese)
CKD is typically associated with ______________ anaemia . Kidney damage reduces erythropoietin production, resulting in reduced haemoglobin production.
normocytic
Lead poisoning is associated with ____________anaemia. High levels of lead reduce haem synthesis resulting in fragile red blood cell membranes and haemolysis.
microcytic
IgE is synthesised by ________________
plasma cells
IgG
75%
Monomer
- Enhance phagocytosis of bacteria and viruses
- Fixes complement and passes to the fetal circulation
- Most abundant isotype in blood serum
IgA
15%
Monomer/ dimer
- IgA is the predominant immunoglobulin found in breast milk. It is also found in the secretions of digestive, respiratory and urogenital tracts and systems
- Provides localized protection on mucous membranes
- Most commonly produced immunoglobulin in the body (but blood serum concentrations lower than IgG
.) - Transported across the interior of the cell via transcytosis
IgM
10%
Pentamer
- First immunoglobulins to be secreted in response to an infection
- Fixes complement but does not pass to the fetal circulation
- Anti-A, B blood antibodies (note how they cannot pass to the fetal circulation, which could of course result in haemolysis)
Pentamer when secreted
IgD
1%
Monomer
- Role in immune system largely unknown
- Involved in activation of B cell
IgE
0.1%
Monomer
- Mediates type 1 hypersensitivity reactions
- Synthesised by plasma cells
- Binds to Fc receptors found on the surface of mast cells and basophils
- Provides immunity to parasites such as helminths
- Least abundant isotype in blood serum
Helper T cells
Involved in the cell-mediated immune response
Recognises antigens presented by MHC class II molecules
Expresses CD4
Also expresses CD3, TCR & CD28
Major source of IL-2
Mediates acute and chronic organ rejection
Cytotoxic T cells
Involved in the cell-mediated immune response
Recognises antigens presented by MHC class I molecules
Induce apoptosis in virally infected and tumour cells
Expresses CD8
Also expresses CD3, TCR
Mediates acute and chronic organ rejection
B Cells
Major cell of the humoral immune response
Acts as an antigen presenting cell
Mediates hyperacute organ rejection
Plasma cells
Differentiated from B cells
Produces large amounts of antibody specific to a particular antigen
Haemophilia A is an ____________disorder.
X-linked recessive
Beta 2 adrenoceptors cause:
vasodilation, bronchodilation, and relaxation of GI smooth muscle
Alpha 1 adrenoceptors cause :
vasoconstriction
relaxation of GI smooth muscle
salivary secretion
hepatic glycogenolysis
Alpha 2 adrenoceptors are found ________ and act to inhibit _________
presynaptically; neurotransmitter release.
They also inhibits insulin + are involved in platelet aggregation
Beta 1 adrenoceptors increase ________ and ______
heart rate and force.
IL -1
IL-1, a pro-inflammatory cytokine released by activated macrophages, plays a pivotal role in the systemic inflammatory response seen in sepsis. It induces vasodilation and increases vascular permeability, leading to decreased systemic vascular resistance and hypotension, a hallmark of septic shock. IL-1’s contribution to the inflammatory cascade also stimulates the further release of cytokines, amplifying the response and the clinical manifestation of sepsis.
IL -10
IL-10, known for its anti-inflammatory properties, works to dampen the immune response by inhibiting the production of pro-inflammatory cytokines. In sepsis, IL-10 aims to counterbalance excessive inflammation and is not directly implicated in causing hypotension or the initial inflammatory response to infection.
IL-12
Produced by dendritic cells and macrophages, IL-12 is crucial for the differentiation of naive T cells into Th1 cells and activating natural killer cells, promoting a cell-mediated immune response. Whilst it plays a role in the immune defence against pathogens, IL-12 does not directly contribute to the vasodilation and hypotension characteristic of sepsis.
IL-3
growth factor that supports the proliferation of haematopoietic stem cells into various blood cells. Its main function is in haematopoiesis rather than the acute inflammatory response or the modulation of blood pressure seen in sepsis.
IL- 6
significantly upregulated in sepsis and contributes to fever and the acute phase response, its role in directly causing hypotension is secondary compared to cytokines like IL-1. IL-6 primarily signals the liver to produce acute phase proteins and aids in B cell differentiation, not vascular tone regulation.
Tumour necrosis factor-alpha is mainly secreted by _________
macrophages
