quiz 6 Flashcards
what is lymph?
fluid derived from blood that has no red blood cells
what does lymph do?
it collects from body tissues, filters through lymph nodes, and eventually returns the blood (gets rid of waste)
what is the relationship between lymph and leukocytes (white blood cells)?
as lymph passes through lymph nodes, leukocytes recognize non-self cells and initiate an immune response
examples of innate, non-specific defenses
skin, mucus, lysozymes, defensins, phagocytosis
antibody
protein produced by lymphocytes that detect antigens (either free antibodies or carried by B cell)
what happens when antibodies bind to an antigen
phagocytes engulf them
how many polypeptide chains does an antibody have? what regions does each chain have?
4 (2 light chains & 2 heavy chains). Each chain has a constant and variable region
variable region
specific for each immunoglobulin, responsible for antibody specificity/antigen binding site
constant region
determines type and helps recruit phagocyte to destroy antigen
VDJ recombination
when a B cell modifies the DNA of it’s variable region by cutting out all VDJ segments except for one of each (creates diversity)
clonal deletion
elimination of potentially harmful lymphocytes that recognize “self” cells
what comes from clonal deletion system failure?
autoimmune diseases
what are the 2 divisions of the adaptive immune system?
humoral immunity (B cells) and cell-mediated immunity (T cells) [both are lymphocytes]
how does humoral immunity work?
activated B cell divides to create plasma cells and memory B cells – plasma cells secrete free antibodies that bind to antigens and recruit phagocytes
how does cell-mediated immunity work?
cytotoxic t cells recognize cells infected by antigen, then divides to create more cytotoxic T cells and memory cells. once bound, cytotoxic T cells can directly kill the pathogen
how do mRNA vaccines work?
mRNA that codes to make a protein that is part of the antigen is packaged in a lipid nanoparticle and delivered into the bloodstream, and produces said protein before getting degraded. your body produces antibodies and memory cells are created.
