Microbiology - Ch. 15 Flashcards
(69 cards)
What are the second line defenses?
o Fever
o Interferon
o Complement
o Inflammation
Examples of PAMPs includes _________
o Peptidoglycan
o Lipopolysaccharide
True or False: Fever & Inflammation are normal body responses to injury or infection, & it may be best to withhold treatment in some cases.
True (Inflammation & fever are host defenses that work to destroy or inhibit the growth of pathogens, Within certain limits and depending on the condition of the host, it is not always necessary or advantageous to treat these.)
The membrane attack complex is a part of the ______ system
Complement
What element is essential for microbes and can restrict the growth of pathogens when bound by antimicrobial proteins?
Iron
First Line Defense
Lysozyme
Lactic acid
Keratin
Lacrimation
Second Line Defense
Fever
Phagocytosis
Inflammation
Interferons
Third Line Defense
Antibodies
T Lymphocytes
B Lymphocytes
What are the correct statements that apply to the role of the resident microbiota in the first line of defense?
o Microbial antagonism contributes to the first line of defense since resident microbiota compete for nutrients & oxygen, limiting availability for pathogens.
o Research suggests that chronic inflammatory disorders, such as Crohn’s disease, are though to arise when the host defenses inappropriately attach the resident biota.
o The beneficial effects of the microbiota are evidenced following broad spectrum antimicrobial therapy; if the resident microbiota are wiped out by a strong antibiotic, a superinfection can prevail.
Host Defenses (Innate)
-First Line of Defense: a surface protection composed of anatomical & physiological barriers that keep microbes from penetrating sterile body compartments.
Physical barriers
Microbiota barrier
Chemical barriers
-Second Line of Defense: a cellular & chemical system that comes immediately into play if infectious agents make it past the surface defenses. (Gamma-delta T cells & natural killer T cells)
Phagocytosis (conducted by neutrophils & macrophages)
Inflammation
Fever
Antimicrobial proteins (includes interferon & complement)
o Acquired
Host Defenses (Acquired)
-Third Line of Defense: includes specific host defenses that must be developed uniquely for each microbe through the action of specialized white blood cells. (Gamma-delta T cells & natural killer T cells)
B/T cells
What is the correct order of phagocytosis?
1.) Phagocytes release chemicals that attract the pathogens
2.) PRRs on host phagocytes bind to PAMPS on microbes
3.) Endocytosis is initiated forming a phagosome
4.) A lysosome fuses with the phagosome forming a phagolysosome
5.) Digestion proceeds as hydrolytic enzymes break down the cells
6.) The residual cell debris is expelled from the cell of exocytosis
The normal microbiota is part of the _______ line of defense.
First
What is the function of the immune system?
Phagocytosis is one way foreign cells are destroyed by the immune system.
What are the characteristics of the lymphatic system of its structure & major functions?
o Helps to regulate the inflammatory response by acting as a “drain-off” system
o Lymph contains a number of immune cells & their products to defend against pathogens
True or False: Whole blood is a substance, consisting of blood cells & clear fluid called serum, which moves through the cardiovascular system
False (plasma is a the fluid that suspends the cells in whole blood. Upon the removal of clotting factors, the fluid is now called serum).
The clear fluid found in whole blood in which the cells are suspended is called _______, however, when the clotting factors are removed, it is now called
Plasma; serum
What are the characteristics of T lymphocytes, which are involved in specific immunity?
o Mature in the thymus
o Move freely among lymphoid tissues & connective tissue
o Responsible for cell-mediated immunity
What is the first stage of phagocytosis all about?
Phagocytes move with deliberation along a gradient of stimulatory products at the site of injury.
Fever is initiated when a substance in circulation, called a _________ acts on the hypothalamus causing it to reset body temperature to a higher setting.
pyrogen
What statements most accurately reflects fever?
Fever enhances metabolism & protective mechanisms in the host.
When a cell is infected by a virus, synthesis of _________ begins and this protein diffuses away from the infected cell to protect nearby uninfected cells by binding to surface receptors and initiating synthesis of antiviral proteins.
Interferon
Nonspecific chemical defenses of the human host include all of the following EXCEPT:
Antibodies. (The other options were hydrochloric acid, lysozyme, & lactic acid.
Which of the following is part of the body’s second line of defense?
Phagocytosis
