Inflammation and Immunity Flashcards
What are the major organs of the immune system?
Tonsils and adenoids, thymus, lymph nodes, lymphatic vessels, appendix, bone marrow, spleen, Peyer’s patches
Name the innate and adaptive cells of humoral (antibody mediated) immunity.
Innate: Myeloid cells (non-host epitopes)
Adaptive: B cells (antibodies, also T helper cells, and APCs)
Name the innate and adaptive cells of cell mediated immunity.
Innate: NK cells (MHC existence)
Adaptive: T cells (MHC1-TCR)
What is the body’s first line of defense?
The skin and mucous membranes.
They act as a physical barrier as well as an antimicrobial peptide barrier
Review the leukocytes involved in immune function and the inflammatory process.
Neutrophils
Monocytes/macrophages
Eosinophils
Basophils
{Platelets and erythrocytes
(all formed from myeloid stem cell)}
What types of leukocytes are the first to appear after injury?
Neutrophils
What role do each of the leukocytes play in inflammation?
Neutrophils: first responders/begin phagocytosis
Macrophages- Ingest microbes and clean up debris after inflammatory response
Eosinophils- degranulate releasing cytotoxic chemical enzymes
Basophils/mast cells- degranulate releasing pro-inflammatory mediators
Describe the concept of a ‘shift to the left of normal’
This shows more circulating immature cells known as band cells which indicates increased neutrophil production and acute infection.
Outline the 3 major types of lymphocytes.
NK cells
T Cells- Helper CD4 and Cytotoxic CD8
B cells
How do the lymphocytes specifically recognize foreign pathogen?
NK cells- innate immunity
Helper T cells(CD4)- via APC (B cells). Helper T cells recognize sequences on the MHC II and active an immune response triggering the release of lymphocytes to respond to a foreign pathogen.
Cytotoxic T cells(CD8)- Recognize the self sequences on the MHC I, if not recognized they active and eliminate.
B cells- Receptors allow B cells to recognize foreign epitopes (specific antigen) and bind/engulf to present to helper T cell. T cells recognize protein are then activated. Exposure to antigens prompts B cells to mature into antibody secreting plasma cells and memory cells.
What is the difference between MHC I and MHC II?
MHC I are surface proteins on the body’s cells indicating the cells belongs there-‘self’. (recognized by cytotoxic T cells and NK cells)
MHC II are surface proteins that bind with antigens and display them for helper T cells. in order to active the immune system (displayed by dendritic, macrophages and B cells and recognized by helper T cells)
Innate and specific/adaptive immunity are different because:
Innate immunity is nonspecific and caused by an immediate degranulation response, while adaptive immunity is mediated by specific B and T cells based on a prior exposure.
Antibodies have two regions:
Constant: determines the class of antibody Variable: contains the sequence specific to the antigen/epitope
What does the complement system do?
The complement system enhances the body’s response to foreign invaders: inflammation, chemotaxis, and lysis of target cells.
What are the different pathways of the complement system and how are they activated?
- Classical pathway- Activated by the C1 protein. Presence of an Ab is essential (IgG or IgM)=formation of antibody-antigen complex.
- Alternative pathway- Activated by C3 protein. Ab not need-can be activated on first exposure to antigen. Triggered by lipopolysaccharide in Gram neg bac walls and bac endotoxin.
- Lectin pathway- Activated by C2 and C4. Ab not need, can be activated on first exposure. Triggered by binding mannose on bacterial walls.
What are Kinins?
Small polypeptides that cause powerful vasodilation, increased vascular permeability and smooth muscle contraction when activated during inflammation. They are also responsible for pain.
How are the kinin and clotting systems linked?
Both the kinin and clotting system are activated by Factor XII (Hageman factor).
How is the complement system controlled?
Enzymes in plasma degrade activators and a number of inhibitory proteins are released. Ex- protein S prevents the complement membrane attack from attaching to and lysing cells.
Where are B and T cells produced and where do they mature?
B cells- Produced and mature in bone marrow
T cells- Produced in the bone marrow and mature in the thymus