Lecture 8 Flashcards
organisms that cause disease, such as bacteria or fungi, are considered ___
pathogens
Skin belongs to the body’s which line of defense?
1st
Fever and inflammation belong to the body’s ______ line of defense.
2nd
What is the third line of defense against pathogens?
adaptive immunity
Which type of defense guards against a broad range of pathogens?
innate
Choose all that are examples of pathogens:
- viruses
- broken bone
- fungi
- bacteria
viruses
fungi
bacteria
The external barrier that is coated with antimicrobial chemicals such as lactic acid, dermicidin, and defensins is ______.
the skin
Which line of defense consists of external barriers?
1st
The organic acid that may be excreted in sweat and inhibits microbial growth is ___ acid
lactic
Which line of defense consists of several nonspecific defense mechanisms against pathogens that break through the skin or mucous membranes?
2nd
Which line of defense not only defeats a pathogen but also leaves the body with a “memory” of it?
3rd
An enzyme found in tears, saliva, and mucus that destroys bacteria by digesting their cell walls is called ___
lysozyme
Adaptive immunity is part of the body’s ______ line of defense.
3rd
The connective tissue of skin and mucous membranes produces ______ acid, a viscous gel that inhibits the migration of microbes.
hyaluronic
What is the tough protein of skin that few pathogens can penetrate?
keratin
Which are granulocytes with a multi-lobed nucleus that destroy bacteria by means of phagocytosis, intracellular digestion, and secretion of bactericidal chemicals?
neutrophils
Which byproduct of fermentation is excreted in the sweat where it inhibits microbial growth?
lactic acid
What does the body’s second line of defense against pathogens consist of?
Antimicrobial proteins, leukocytes, and macrophages
When a neutrophil discharges its enzymes into the tissue fluid, they are said to ______.
degranulate
choose all that describe lysozyme:
- an enzyme
- found in saliva, tears, and other body fluids
- an antibody
- capable of destroying bacteria
- part of the specific defenses
an enzyme
found in saliva, tears, and other body fluids
capable of destroying bacteria
Choose all the mechanisms used by eosinophils to kill parasites:
- secrete histamine
- secrete histaminase
- produce superoxide anion
- produce hydrogen peroxide
produce superoxide anion
produce hydrogen peroxide
Some bacteria produce which enzyme that allows them to more readily spread throughout connective tissues?
hyaluronidase
connective tissues normally produce hyaluronic acid (viscous substance) that is hard for pathogens to penetrate.
Pathogens then secrete hyaluronidase to break the hyaluronic acid thinner and easier to penetrate
Which is an anticoagulant secreted by basophils and mast cells?
heparin
Which leukocyte destroys bacteria by means of phagocytosis, intracellular digestion, and the secretion of bactericidal chemicals?
neutrophil
Which leukocytes are responsible for adaptive immunity?
lymphocytes
The organic acid that may be excreted in sweat and inhibits microbial growth is ___ acid
lactic
The cell that migrates into the tissues where it transforms into a macrophage is called a(n) ___
monocyte
Choose all of the following that the respiratory burst by neutrophils leads to:
- hydrogen peroxide
- superoxide anion
- histamine
- heparin
- hypochlorite
hydrogen peroxide
superoxide anion
hypochlorite
What type of cell phagocytizes antigen antibody complexes, allergens, and inflammatory chemicals and secretes histaminase and other molecules that combat parasitic infections?
eonsinophil
where are alveolar macrophages located?
lungs
What are three inflammatory mediators released by basophils and mast cells?
- heparin
- histaminase
- hypochlorite
- histamine
- leukotriene
heparin
histamine
leukotriene
Interferons and complement are examples of which of the following?
antimicrobial proteins
Most lymphocytes circulating in blood are ______.
T cells
Which substance induces the production of antiviral proteins?
interferons
Which leukocyte transforms into a macrophage when it moves from the blood into the tissues?
monocyte
where are complement proteins mainly produced?
liver
What is the exocytosis of lysosomal contents by neutrophils called?
degranulation
True or false: Complement functions to induce pathogen destruction by inducing apoptosis.
false
what are the 4 ways complement functions to destroy pathogens?
inflammation
immune clearance
phagocytosis
cytolysis
What type of macrophage moves into a specific tissue, then remains within that tissue waiting to phagocytize pathogens?
fixed
Which complement pathway is antibody-mediated?
classical
what are the 3 complement pathways? Are they antibody-independent or dependent?
classical –> antibody-dependent
alternative –> antibody-independent
lectin –> antibody-independent
What are two antimicrobial proteins?
- mucous membrane
- stomach acid
- macrophage
- inteferon
- complement
interferon
complement
Cytokines known as ___ inhibit the viral infection of neighboring cells as well as activate NK cells and macrophages.
interferons
A cytolytic protein secreted by NK cells is ______.
perforins
Which proteins found in blood are involved in the nonspecific defense against pathogens?
complement
Fever inhibits the production of ______.
bacteria
What are the mechanisms of complement that induce pathogen destruction?
inflammation
immune clearance
phagocytosis
cytolysis
Self proteins, such as interferon and interleukins, that induce fever are called ______ pyrogens.
endogenous
The alternative, classical, and lectin pathways are the three pathways to activate what?
complement
Where is body temperature regulated?
hypothalamus
Interferons and complement are examples of which of the following?
antimicrobial proteins
Redness, heat, swelling, and pain are signs that accompany which process?
inflammation
NK cells induce apoptosis in virally infected cells by secreting which protein-degrading enzymes?
granzymes
What are two cell types that secrete histamine, heparin, leukotrienes and kinins, thus inducing the inflammatory response?
basophils
mast cells
True or false: All fevers are detrimental and should be treated immediately with an antipyretic.
false
what 3 things does a fever accomplish?
1) promotes interferon activity
2) inhibits reproduction of bacteria and virus
3) elevates metabolic rate and accelerates tissues repair
What does hyperemia result from?
vasodilation
Any surface glycolipid on a bacterium or virus that stimulates fever is what type of pyrogen?
exogenous
Leukocytes crawl through gaps between endothelial cells into the tissue fluid by means of a process called
diapedesis OR emigration
What is the part of the brain that regulates and maintains body temperature?
hypothalamus
An elevated neutrophil count is called ______.
neutrophilia
Choose all that are the cardinal signs of inflammation?
- heat
- pain
- hemorrhage
- itchiness
- swelling
- redness
heat
pain
swelling
redness
what are the 4 cardinal signs of inflammation?
heat
pain
swelling
redness
What class of chemical agents do interleukins and interferons belong to?
interferons
what are cytokines?
small proteins that help regulate inflammation and immunity
act as chemical communication network among immune cells
The accumulation of dead cells, fluid, and tissue debris is called ___.
pus
Hyperemia is the basis for which cardinal inflammatory signs?
redness
heat
Which is secreted by platelets and endothelial cells and stimulates the synthesis of collagen and multiplication of fibroblasts?
platelet derived growth factor
During the inflammatory response, leukocytes traveling through the blood adhere to the blood vessel walls by which process?
margination
An individual with a parasitic infection would likely have which of the following?
eosinophilia
Redness, heat, swelling, and pain are signs that accompany which process?
inflammation
Which of the following forms pus?
dead neutrophils and macrophages
Platelets and endothelial cells secrete platelet-derived ___ factor, which stimulates the synthesis of collagen and multiplication of fibroblasts.
growth
how does the complement system lead to inflammation?
antigen-antibody complexes form on pathogen surface
reaction cascade
C3 dissociates into C3a
C3a binds to basophils and mast cells
binds to basophils and mast cells, stimulates neutrophils and macrophage activity –> releases histamine and other inflammatory chemicals
–> inflammation
how does the complement system lead to immune clearance?
C3 dissociates into C3b
C3b binds to pathogen surface
reaction cascade
C3b binds Ag-Ab complexes to RBCs
RBCs transport Ag-Ab complexes to liver and spleen
phagocytes remove and degrade Ag-Ab complexes
–> immune clearance
how does the complement system lead to phagocytosis?
C3 dissociates into C3b
C3b coats bacteria, viruses, and other pathogens –> opsonization
–> phagocytosis
what are the 3 pathways to activate the complement system?
classical pathway (antibody-dependent)
alternative pathway (antibody-independent)
lectin pathway (antibody-independent)
how does the complement system lead to cytolysis?
C3 dissociates into C3b
C3b splits C5 into C5a and C5b
C5b binds C6, C7, and C8
C5b678 binds ring of C9 molecules
membrane attack complex
–> cytolysis
