Overview of the Immune System Flashcards
Study of how the human body protects itself from threats from w/out and from w/in?
Immunology
Immune system consists of cells, organs, & molecules that are all concerned w/ ___ & ___ to infection and malignancies.
defense & resistance
5 main categories of disease-causing organisms or pathogens:?
virus, bacterium, fungus, protozoal parasite, & multicellular parasite
Agent that has the potential to cause disease?
Pathogen
Pneumonia, Tetanus, Sleeping sickness, & Pneumocytsis pneumonia are all what type of pathogen?
Extracellular bacteria, parasites, fungi
Leprosy, Leishmaniasis, & Malaria are all what type of pathogen?
Intracellular bacteria, parasites
Smallpox, flu, & chickenpox are all what type of pathogen?
Viruses (intracellular)
Ascariasis & Schistosomiasis are what type of pathogen?
Parasitic worms (extracellular)
Anything (self or non-self) that can be recognized by the immune system?
Antigen
What are some common antigens?
proteins, carbohydrates, lipids, and even nucleic acid
Anything (self or non-self) that can induce an immune response?
Immunogen
Can all antigens elicit responses on their own?
No, some of them require help to elicit responses
The portion of an antigen that is recognized by the immune system. Also, called “antigenic determinant”
Epitope
What components of the immune system recognizes these epitopes?
T lymphocytes & B lymphocytes
What does the 3-Tiered approach to defense consist of?
Barrier, Innate immunity, & Adaptive immunity
When encountering any infectious organism what immune system responds first?
Innate immune response
This immunity mechanism: rapid reponse (hours), fixed, limited # of specificities, & constant during response?
Innate immunity
This immunity mechanism: slow response (days to weeks), variable, # highly selective specificities, & improve during response?
Adaptive immunity
This immune response is present from birth & not antigen-specific?
Innate immune response
This immune response is not enhanced by 2nd exposure, no memory, & enhanced by adaptive immunity?
Innate immune response
Components of innate immunity?
phagocytes, Granulocytes, Antigen presenting cells, cytotoxic cells, & soluble factors
Adaptive immune response components?
T cells & B cells
This immune response is: induced, delayed; specificity; diversity; tolerance of self; memory?
Adaptive immune response
Ability to discriminate between harmless (self) & potentially harmful (non-self) antigens?
Tolerance of self
This describes the ability of the immune system to respond more rapidly and more vigorously against pathogens that it has previously encountered?
Memory
T cells can further be subdivided into?
CD4 cells (helper cells) & CD8 cells (Cytotoxic T cells/killer cells)
Activated CD4 T cells secrete a wide variety of messenger molecules called?
Cytokines
T cells cannot recognize free antigen & require antigen to be presented to them by cells called?
Antigen Presenting cells (APC)
Low molecular weight proteins that regulate the intensity & duration of the immune response by exerting a variety of effects on lymphocytes & other immune cells?
Cytokines
Examples of cytokines
Interleukins (IL) & Interferons (IFN)
Innate and adaptive immune cells are called?
Leukocytes (white blood cells)
2 primary groups of leukocytes
Granulocytes & Agranulocytes
Neutrophils, basophils, and eosinophils are from what primary group
Granulocytes
Monocytes & lymphocytes are from what primary group
Agranulocytes (mononuclear cells)
What cell type has proportion leukocyte % less than 1% & what has 40-75%?
<1%: Basophil
40-75%: Neutrophil
What cell type has proportion leukocyte % 2-10% & what cell type 20-50%?
2-10%: monocyte
20-50%: Lymphocyte
CD34+
Hematopoietic stem cell
The lymphoid lineage contains?
T cells, B cells, & natural killer cells
The myeloid lineage contains most of the cells of the innate immune system but also includes?
Dendritic cells
Macrophage: tissue designations for liver
Kupffer cells
Macrophage: tissue designation for connective tissue
histiocytes
What allow the innate immune system to detect pathogens
Pattern recognition receptors (PRRs)
Surface wound introduces bacteria, which activate resident effector cells to secrete?
Cytokines
What allow fluid, protein, & inflammatory cells to leave blood & enter tissue?
Vasodilation & increased vascular permeability
What take up antigens in peripheral sites & carry them to 2nd lymphoid tissues?
Dendritic cells
What forms the bridge between innate & adaptive immune response?
Dendritic cells
Bone marrow and Thymus. Sites where lymphocytes develop or mature?
Primary (central)
Spleen, Lymph nodes, Mucosal associated lymphoid tissues. Sites where immune responses or organisms or molecules are induced?
Secondary (peripheral)
CD4 or CD8
T cells
What in lymphocytes produces antibodies?
B cells
What takes up most of cell in lymphocytes?
Nucleus
During development in primary lymphoid tissue lymphocytes generate unique antigen receptors by?
gene rearrangement
The development & survival of lymphocytes is determined by signals received through their _______ ______
antigen receptors
T cell receptors only recognize peptide fragments of antigens bound to proteins of the?
major histocompatibility complex
Adaptive immune responses are initiated by antigen & antigen-presenting cells in ____ lymphoid tissues
secondary
T cell area of lymph nodes
paracortex
B cell area of lymph nodes
follicles in cortex
Lymphocytes enter Secondary lymphoid tissues via ?
High Endothelial venules
Lymphocytes entry into tissues is dependent on specific adhesive interactions between specific what?
Cell adhesion molecules (CAMs)
Peyer’s patches are covered by an epithelial layer containing specialized cell called __ cells which have characteristic membrane ruffels
M cells
What immune response are initiated in organized lymphoid structures?
Adaptive immune response
B cells activated by antigen & helped by T cells become what?
Plasma cells (Antibody-secreting cells)
When does Germinal centers form?
After T cells help B cells
What type of T cells recognize MHC class 1 & become cytotoxic (CTL)?
CD8 T cells
What type of T cells recognizes complex of bacterial peptide w/ MHC class II & activates macrophage?
CD4 T cells (helper cells)
CD4 T cells (__) recognize MHC class II & help B cells
Th2
