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