Answers 2024/2025
Innate/Natural Immunity - ANSWERSPresent in healthy individuals; nonspecific; rapid response
Ex: epithelial barriers, phagocytes, and inflammation
Acquired/Adaptive Immunity - ANSWERSFrom prior experience with AGN mediated by lymphocytes;
antigen specific; slow response & memory
Ex: lymphocytes & their products (such as antibodies) involved
Humoral Immunity - ANSWERSMediated by antibodies; produced by B-cells; protects against
extracellular microbes/microbial toxins
Cell-Mediated Immunity - ANSWERSMediated by T cells which produce substances to activate
phagocytes; protects against intracellular microbes/microbial toxins; some T cells may kill host cells
harboring microbes
Active Immunity - ANSWERSHost makes their own antibodies (infection or vaccination); long lived
resistance
Ex: use of vaccines against HBV, measles, polio
Passive - ANSWERSAntibodies are made by another organism; antibodies transferred from and actively
immunized organism; short lived immunity
Ex: newborn being breast fed
B-Cell Specificity - ANSWERSImmunoglobulins attached to their membrane- cross linking of antibodies
T-Cell Specificity - ANSWERSHave receptors (TCR)- interaction of many surface proteins
,Specificity - ANSWERSActivated through interaction of antigen & lymphocyte's specific antigen receptors
Diversity - ANSWERSLymphocytes random selection of gene segments resulting in thousands of different
variable region sequences; potential for recognizing at least a billion antigens
Clonal Selection - ANSWERSSurface receptors bind to specific epitopes with high affinity and avidity
stimulating, activation, proliferation, and differentiation
Memory - ANSWERSResponse against an antigen is heightened upon re-exposure
Primary Immune Response - ANSWERSResponse to first exposure; mediated by a naive lymphocyte
(seeing antigen for the first time)
Secondary Immune Response - ANSWERSReferred to as anamnestic response; usually more rapid, and
larger (eliminating the antigen better); result of "memory" lymphocytes
Immunological Homeostasis - ANSWERSConfers health by responding and controlling infection with
moderation
Immunization - ANSWERSInjecting an antigen to cause immunity by inducing a protective immune
response against specific organisms or its associated toxin prior to the encounter with the pathogen
Immunogen - ANSWERSForeign substance the induces an immune response
Antigens - ANSWERSForeign substance that is capable of producing an immune response; can be harmful
or harmless
Regulation - ANSWERSControl and inhibit self-reactive or over-reactive responses by lymphocytes; keeps
the immune system from attacking the host by elimination, permanent inactivation, & inhibition
External Defenses - ANSWERSDesigned to keep microorganisms from entering the body
Ex: normal flora, skin, mucosal secretions, tears, sweat, ph
, Internal Defenses - ANSWERSClears internal invaders after external defense has been breeched
Ex: inflammation
Clinical Signs of Inflammation - ANSWERSRedness (rubor), heat (calor), swelling (tumor), pain (dolor)
Inflammation - ANSWERSReaction of the body tissue injury or infection that is designed to bring
phagocytic cells and molecules to the area & isolate the area from the rest of the body
Cell Commonly Seen in Acute Inflammation - ANSWERSNeutrophil (PMN)
*Function returns to normal*
Cell/s commonly seen in chronic inflammation - ANSWERSMacrophages & lymphocytes
*Prolonged; may adversely affect function*
Phagocytosis Sequence of Events - ANSWERS1. Increased blood supply to area, due to dilation of blood
vessels
(chemical mediators released dilate vessels; rubor & calor)
2. Increased vascular permeability caused by retraction of endothelial cells lining blood vessels
(allow fluid in plasma to leak to tissues; tumor & dubor)
3. Influx of phagocytes
(facilitated by more capillary permeability; PMNs arrive first; followed by macrophages)
Acute Phase Reactants - ANSWERSIncrease rapidly with infection, surgery, or other trauma; normal
serum constitutes; made mostly by the liver; nonspecific; first-line defense
Ex: Complement & CRP
CRP (C-reactive protein) - ANSWERSCommon indicator of acute inflammation; coats foreign particles and
activates complement; increases within 4 to 6 hours; declines rapidly when the stimulus ceases; hsCRP is
useful for predicting cardiovascular risk