Immunology Flashcards
the ability to ward off disease caused by microbes or their
products and to protect against environmental agents
Immunity
lack of immunity
Susceptibility
response generated against a potential pathogen
Immune response
Innate Immunity
– Immediate
– Not long-lasting
– Nonspecific
– Lacks immunologic memory
– First line of defense
Adaptive Immunity
– Responds rapidly to 2nd exposure
– Specific
– Has immunologic memory
– Second line of defense
Skin and Mucous Membranes
■ Epidermis
■ Mucus in mucous membranes
■ Cilia in respiratory tract
■ Tears
■ Saliva
■ Flow of urine
■ Vaginal secretions
■ Defecation and vomiting
■ Sebum
■ Gastric acid
■ Lysozyme
■ Normal microbiota
Formed Elements in the Blood
■ Erythrocytes/RBCs
■ Leukocytes/WBCs
■ Platelets
Pluripotent stem cells
myeloid cell
lymphoid stem cell
Myeloid cell
Granular leukocytes (whiteblood cells)
Erythrocyte
Megakaryocyte-platelets
Granular leukocytes (whiteblood cells)
Mast cell
Eosinophil
Basophi
Neutrophil
Lymphoid stem cell
Agranular leukocytes (white blood cells)
Agranular leukocytes (white blood cells)
Monocytes- dendritic cell and Macrophage
t-cell
B-cell- plasma cell
Natural killer Cell
Neutrophils
function: Phagocytosis
Basophils
production of histamine
Eosinophils
Production of toxic proteins against certain parasites; some Phagocytosis
Monocytes
Phagocytosis when they mature to macrophages
dendritic cells
Phagocytosis and initiation of adaptive immune response
lymphocytes
Natural killer cells
Function: Destroy target cells by cytolysis and apoptosis
Granulocytes (Neutrophils, Eosinophils) and
Monocytes/Macrophages/Dendritic Cells
Phagocytes
ingestion of a microorganism or other substance by a
cell
Phagocytosis
population
of cells that descend from monocytes
Reticuloendothelial (Mononuclear Phagocytic) System
resident in certain tissues and
organs of the body
Fixed Macrophages/Histiocytes
roam the tissues and gather at
sites of infection/inflammation
Free/Wandering Macrophages
Fixed Macrophages
■ Kupffer cells- liver
■ Alveolar macrophages-lungs
■ Microglial cells- CNS nervous system
■ Langerhans Cells-skin
■ Splenic macrophages-splein
■ Peritoneal macrophages-peritonial
consists of a fluid (lymph), vessels (lymphatic vessels), and structures and organs
containing lymphoid tissue
Lymphatic System
Primary Lymphatic Organs
where stem cells divide and become immunocompetent
– e.g. bone marrow and thymus
Secondary Lymphatic Organs/Tissues
– where most immune responses occur
– e.g. lymph nodes, spleen, tonsils, Peyer’s patches, appendix, MALT (mucosa-
associated lymphoid tissue)
– contains large numbers of lymphocytes and phagocytes
– Lymph nodes – sites of activation of T cells and B cells
sites of activation of T cells and B cells
Lymph nodes
Complement System
consists of >30 proteins produced by the liver that circulate in the
blood and within tissues
3 pathways: all end in activation of C3
– Classical
– Alternative
– Lectin
Outcomes of Complement Activation
Cytolysis
opsonization
inflammation
Inflammation
a nonspecific, defensive response of the body to tissue damage
5 cardinal signs and symptoms of inflammation
– Pain
– Redness
– Loss of function
– Swelling
– Heat
Functions:
– to destroy/remove the injurious agent
– if destruction/removal is not possible, to limit the effects
on the body by confining or walling it off
– to repair or replace damaged tissue
Inflammation
Steps
1. Vasodilation and Increased Permeability
2. Phagocyte Migration and Phagocytosis
3. Tissue Repair
Inflammation
Acute Inflammation
– develop rapidly and last for
a few days or weeks
– mild and self-limiting
– principal defensive cells: neutrophils
Chronic Inflammation
– develop slowly and last up
to several months or years
– severe and progressive
– principal defensive cells:
monocytes and
macrophages
abnormally high body temperature due to resetting of the
hypothalamic thermostat
Fever
Fever
■ intensifies the effect of interferons
■ may help tissue repair
■ IL-1 - helps step up T cell production
■ a family of cytokines
■ produced by fibroblasts, lymphocytes and macrophages
■ inhibit viral replication
Interferons (IFNs)
3 types of interferons in humans
– alpha interferon (IFN-ɑ)
– beta interferon (IFN-β)
– gamma interferon (IFN-γ)
has ability to differentiate between normal “self” cells and
“nonself” also in innate
Adaptive Immunity
distinguished from innate immunity by its specificity and
memory like combat specific pathogen or antigen while innate- nonspecific ombats any pathogen
Adaptive Immunity
The Dual Nature of Adaptive Immunity
Humoral and cell mediated immunity
Mediated by B cells
Humoral Immunity
Mediated by T cells
Cell mediated
Acts on extracellular microbes and their toxins
Humoral immunity
Acts on itracellular microbes such as Viruses, bacteria, and parasites and tumor cells
Cell mediated Immunity
Primary lymphatic organs
Red bone marrow
Thymus
Red bone marrow lng
B cells -Humoral
red bone marrow and thymus
mature t cells-cell mediated immunity
