Exam 3 Review sheet Flashcards
Mechanical Barrier
rinse, flush, or trap pathogens to limit their spread into the body
Mechanical Barrier: Examples
tears, urine, saliva, mucus membranes
Chemical Barrier
may directly attack invaders or establish environments that limit pathogen survival in or on a particular tissue
Lysozyme
found in secretions (e.g., tears, breast milk) and breaks down bacterial cell walls
Inflammation
essential to healing and immunity, but if unregulated it starts to damages our own tissues
Neutrophils
Most numerous white blood cells in circulation
Contain multilobed segmented nucleus
First leukocytes recruited to injured tissues
Lymphocytes
Account for ~25% of circulating WBC
Contain large rounded nucleus and limited cytoplasm
Include Natural killer (NK) cells, B cells, and T cells
Eosinophils
Account for <5% of the total WBC population
Possess granules containing diverse enzymes and antimicrobial toxins
Combat parasitic infections
Basophils
<1% of WBC population
Possess granules packed with defense molecules (e.g., histamine)
Combat parasitic infections and have roles in allergic responses
Monocytes
Account for ~10% of circulating leukocytes
Levels can increase due to chronic infections and inflammation, autoimmune disorders, and certain cancers
Migrate out of the circulatory system into tissues and mature into macrophages
Macrophages
Highly phagocytic
Destroy a wide range of pathogens
Granulocytes
cells with granules in their cytoplasm that are visible when stained
Agranulocyte
lack granules in cytoplasm
Cytokine
Signaling proteins that allow cells to communicate with each other, initiating and coordinating immune actions
Hapten
stimulates the production of antibody molecules only when conjugated to a larger molecule, called a carrier molecule
Antigen
Any substance that, if presented in the right context, may trigger an immune response
Immunological memory
Secondary exposure to the same antigen is rapid and effective
Immune
Specific protection conferred by adaptive immune responses
Susceptible
Not immune to a given pathogen and it may cause infection
Which cells are APCs ?
Dendritic cells, Macrophages, B cells
What role does an APC do?
APCs show antigen to T cells
How is lysozyme an important part of the innate immune system?
Since they’re a form of chemical barrier they directly attack the pathogen by breaking down bacterial cell walls.
What are the goals of the first-line defenses?
Attempt to prevent pathogen entry
What are the goals of the second-line defenses?
When first line defenses are breached, parts of the secondary are activated
What are the primary lymphoid tissues?
Thymus and bone marrow
What are the secondary lymphoid tissues?
Lymph nodes, spleen, and mucosa-associated lymphoid tissue (MALT)
What does primary Lymphoid tissue do?
Site of production and maturation of leukocytes
What does secondary lymphoid tissue do?
Filter lymph
Innate immunity vs. adaptive immunity
Innate:
Inborn, ancient protection existing in one form or another in all eukaryotic organisms
Generalized responses
Non-specific immunity
Adaptive:
Only in vertebrate animals
Matures over time
Responses tailor to pathogens
Typically requires 4–7 days to fully activate
Exhibits memory
structure of an antibody
2 heavy protein chains
2 light protein chains
Held together by covalent bonds
the role of antibodies
Bind to antigens that are triggered B cell’s activation
directly neutralize antigens to prevent them from interacting with target host cells
what are the 5 different antibodies?
Snow Gathers At Every Door:
IgM, IgG, IgA, IgE, IgD
what do the 5 different antibodies do?
IgM: Made early in infection upon a primary antigen exposure
IgG: Crosses the placenta. Detecting IgG to a particular antigen indicates the patient has been exposed to that antigen
IgA: Found in secretions (e.g., tears, saliva, sweat, and breast milk)
IgE: Functions to fight parasites and mediate allergic responses
IgD: Unknown
What are the different WBCs?
Granulocytes: Neutrophils, Eosinophils, Basophils, Mast Cells
Agranulocytes: Lymphocytes, Monocytes, Dendritic Cells
Roles for Neutrophil
First leukocytes recruited to injured tissues
Release potent antimicrobial peptides (AMPs)
Phagocytize foreign cells and viruses
Elevated neutrophil count may indicate an acute bacterial infection
Most numerous white blood cells in circulation
Role for Eosinophils:
Account for <5% of the total WBC population
Contain large cytoplasmic granules that stain red-orange
Possess granules containing diverse enzymes and antimicrobial toxins
Exhibit moderate phagocytic activity
Combat parasitic infections
Role For Basophils:
<1% of WBC population
Contain a double-lobed nucleus and cytoplasmic granules
Possess granules packed with defense molecules (e.g., histamine)
Combat parasitic infections and have roles in allergic responses
Role for Mast Cells:
Release histamine
Play a role in allergies and fighting parasites
Able to conduct phagocytosis
Common in tissues near body openings (e.g., skin and mucous membranes of the airway and gastrointestinal tract)
Role for Lymphocytes:
Account for ~25% of circulating WBC
Contain large rounded nucleus and limited cytoplasm
Include Natural killer (NK) cells, B cells, and T cells
Role for Monocytes:
Largest agranular white blood cells
Account for ~10% of circulating leukocytes
Migrate out of the circulatory system into tissues and mature into macrophages (which are highly phagocytic)
Role for Dendritic Cells:
Highly phagocytic
Found in most body tissues
Patrol tissues and phagocytize a broad range of antigens
What is the role of MHC I in the immune response?
Presenting Intracellular Antigens to T Cytotoxic Cells
What is the role of MHC II in the immune response?
Presenting Extracellular Antigens to T Helper Cells
