Exam 1 Review Flashcards
The enzyme responsible for cleaving C3 into C3a and C3b is called C3 convertase, and it differs in composition depending on the particular complement pathway. The classical and lectin pathways use the classical C3 convertase (C3bBb), whereas the alternative pathway uses the alternative convertase (C4b2a).
False
Which of the following complement components is an opsonin that binds to complement receptor 1 (CR1) on macrophages?
a. C3b
b. C3a
c. Bb
d. Ba
e. C3bBb
C3b
_____ are soluble complement fragments that mediate localized and systemic inflammatory responses.
a. cryptdins
b. defensins
c. anaphylatoxins
d. selectins
e. C-reactive proteins
anaphylatoxins
All of the following are examples of chemical barriers of innate immunity except _____.
a. lactic acid
b. normal microbiota
c. lysozyme
d. fatty acids
e. proteases
normal microbiota
Regarding the three pathways of complement: (1) The classical pathway requires an activating surface of a pathogen, which stabilizes complement components. (2) The lectin pathway requires the presence of mannose-binding lectin, an acute-phase protein made by the liver in response to interleukin-6 (IL-6) (secreted by activated macrophages) and which accumulates in plasma during infection. (3) The alternative pathway is activated in two ways, either by the presence of antibody bound to the surface of the microorganism (for example IgM bound to lipopolysaccharide of Gram-negative bacteria) or by the presence of C-reactive protein bound to a bacterium.
False
Which of the following Toll-like receptors are expressed exclusively by NK cells? (Select all that apply.)
a. TLR3 and TLR8
b. TLR2 and TLR4
c. TLR1 and TLR2
d. TLR5 and TLR9
e. TLR1, TLR2, and TLR6
TLR3 and TLR8
_____ is(are) a soluble protein(s).
a. TLR4
b. TLR2
c. lipopolysaccharide-binding protein (LBP) and mannose-binding lectin (MBL)
d. CXCR1
e. TLR1
lipopolysaccharide-binding protein (LBP) and mannose-binding lectin (MBL)
Lectins recognize microbial _____.
a. phosphate-containing lipoteichoic acids
b. nucleic acids
c. carbohydrates
d. flagellin
e. peptides
carbohydrates
The spleen differs from other secondary lymphoid organs in which of the following ways?
a. It does not contain T cells.
b. It filters blood as well as lymph.
c. It is populated by specialized cells called M cells.
d. It receives pathogens via afferent lymphatic vessels.
e. It has no connection with the lymphatics.
It has no connection with the lymphatics.
C-reactive protein binds to _____.
a. phosphorylcholine
b. mannose-containing carbohydrates
c. lipoteichoic acid
d. flagellin
e. MASP-1/MASP-2
phosphorylcholine
Which of the following does not accurately describe complement components?
a. soluble proteins
b. made by the spleen
c. located in extracellular spaces
d. some function as proteases once activated
e. activated by a cascade of enzymatic reactions
made by the spleen
The first line of defense against microorganisms that infect the body is referred to as _____.
a. opportunistic immunity
b. innate immunity
c. adaptive immunity
d. primary immunity
e. central immunity
innate immunity
Primary lymphoid tissues are the sites where lymphocytes _______, whereas secondary lymphoid tissues are the sites where lymphocytes _______.
a. are stimulated; develop and mature
b. encounter pathogens; undergo apoptosis
c. develop and mature; become stimulated
d. undergo clonal selection; differentiate from hematopoietic stem cells
e. die; are phagocytosed after death
develop and mature; become stimulated
Toll-like receptors differ from scavenger receptors in that they _____.
a. bind to common repetitive arrays on microbial surfaces
. stimulate a pathway that causes enzymatic degradation of the microbe to which they bind
c. are soluble receptors that bind to microbes in extracellular spaces
d. mediate signal transduction pathways, causing cytokine production
donâ t mediate signal transduction pathways, causing cytokine production
mediate signal transduction pathways, causing cytokine production
A term generally used to describe all white blood cells is _____.
a. hematopoietic cells
b. myeloid progenitor
c. dendritic cells
d. monocytes
e. leukocytes
leukocytes
