Mechanisms of Defense Flashcards
Definition of immunity (3 parts)
State of being immune or insusceptible to a particular disease
Condition that permits either natural or acquired resistance to disease
Ability of a cell to react immunologically in the presence of an antigen
What are the 3 features of the defense mechanism (complex interacting networks)?
Physical barriers
Innate immunity
Adaptive immunity
Two types of adaptive (specific) immunity
Antibody mediated
Cell mediated
Which of the types of adaptive immunity is directed against bacterial invaders?
Antibody mediated. Antibodies are proteins in the bloodstream that bind to bacteria and mark them for destruction.
What type of adaptive immunity is directed against viral invaders?
Cell mediated. Employs the cells that destroy abnormal cells, such as those infected by viruses, and is important in destruction of cancer cells.
What feature of adaptive immunity ensures health and survival in the face of continuing microbial challenge?
Ability to remember prior exposure and respond faster and more efficiently on subsequent exposures.
Examples of physical barriers
Skin
Self-cleaning
Normal flora
Examples of innate (non-specific) immunity
Inflammation
Defensins
Lysozyme
What is the most effective portion of the defense mechanism?
Adaptive immunity (cell mediated and antibody mediated)
What type of immune response is not dependent on an antigen, acts rapidly, and usually doesn’t leave any memory?
Innate (non-specific) immunity
What type of immune response is antigen-specific, is delayed in action, and leaves memory?
Adaptive (specific) immunity
2 divisions of innate immune system
Cells that eat and kill invaders
Molecules that bind and kill invaders
Examples of innate immune cells that detect, eat, and kill invaders
Phagocytes
Natural killer cells
Roles of molecular portion of innate immune system
Bind and kill invaders Coat invaders Block microbial growth Prevent microbial spread Mobilize body defenses
Where would the pathogen be located if cells are able to produce antibodies?
Outside the cell (extracellular)
Where is the pathogen located when cell mediated immunity comes into play?
Inside the cell. (Intracellular)
employs cells that destroy infected cells
Where does hematopoiesis (production of immune cells) take place?
In bone marrow
Hematopoiesis includes production of…
Immune cells
Red blood cells
Platelets
Components of the blood (layers)
Plasma
Erythrocytes
Buffy coat
Plasma layer includes
Water
Proteins
Electrolytes, nutrients, waste
Buffy Coat layer includes
Platelets Leukocytes Neutrophils (60-70%) Lymphocytes (20-25%) Monocytes Eosinophils Basophils
3 major lineages of Hematopoiesis
Erythroid
Myeloid
Lymphoid
What lineage of hematopoiesis produces erythrocytes and platelets?
Erythroid
What lineage of hematopoiesis produces lymphocytes (T and B cells) and Natural Killer cells?
Lymphoid
What cells does the myeloid lineage of hematopoiesis produce?
Granulocytes Mast cells Monocytes Macrophages Myeloid dendritic cells
Adaptive immunity is mediated by lymphocytes mainly found where?
Lymphoid organs
Characteristics of lymphocytes
Can specifically recognize and distinguish different antigens
Adaptive immune response, specificity, and memory
Morphologically indistinguishable despite different functions and protein products
What are the bursa or bone marrow derived lymphocytes?
B Lymphocytes
Which lymphocytes mature in the Thymus?
T Lymphocytes.
*Helper T, cytotoxic
What happens to lymphocytes that have receptors for self antigens?
Killed before they can leave primary lymphoid organs.
*If not, cause autoimmune disorders (Lupus)
