RNC INFECTIOUS DISEASES QUESTIONS AND ANSWERS UPDATED
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
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Host defense mechanisms - CORRECT ANSWERS Overall functions of the immune system.
a. Defense—resistance to infection by microorganisms.
b. Homeostasis—removal of worn-out cells.
c. Surveillance—perception and destruction of mutant cells.
2. Components of the immune system. a. The nonspecific mechanisms, which include
phagocytosis, the inflammatory response, and several amplification systems including
complement, coagulation, and kinin systems.
b. The specific immune responses, which consist of cell-mediated (T cell) and humoral (B cell)
systems. (1) Both are interdependent and interrelated; for example, the activation of the
complement system by immunoglobulins (IgM and IgG), or the production of chemotactic
factors and other lymphokines, plays a significant role in the whole inflammatory response.
(2) Nonspecific immune mechanisms—function without prior exposure, identified early in
gestation, functional development at 32 to 33 weeks.
c. Embryologic development (Table 32-1). (1) The maturation of specific immune responses
begins in utero during the 7th to the 12th weeks of gestation.
(2) Progenitor cells (stem cells) are initially located in the yolk sac, fetal liver, and bone marrow
of the developing embryo.
d. Depending on the type of microchemical environment surrounding the tissue, the stem cells
will differentiate along at least two pathways: (1) The hematopoietic.
,RNC INFECTIOUS DISEASES QUESTIONS AND ANSWERS UPDATED
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
CORRECT VERIFIED/DETAILED BEST RATED A+ FOR SUCCESS
(2) The lymphopoietic. (a) The lymphopoietic system develops along two independent
pathways leading to morphologically and functionally distinct populations of immune systems:
(i) The thymus-derived or T system of cell-mediated immunity whose principal effector cells are
the T lymphocytes.
(ii) The bursal-dependent or B system of humoral or antibody-mediated immunity, which is
displayed by the B lymphocytes.
(3) The thymus gland is derived from epithelium of
Humoral Immunity - CORRECT ANSWERS 1. Immunoglobulin (McCance and Huether, 2002;
Polin et al., 2001).
a. Humoral immunity is a specific antibody-mediated response that functions most effectively if
there has been previous exposure.
b. Antibodies are derived from B cells, which have been activated by T cells and antigens (Fig.
32-1).
(1) B cells mature and are stored in lymph tissue and bone marrow.
(2) B cells also produce memory cells that recognize antigens on subsequent exposures and
initiate an antibody response.
(3) Antibody functions include: (a) Recognition of bacterial antigens.
(b) Neutralization or opsonization of foreign substances, rendering them susceptible to
phagocytosis.
2. Types of immunoglobulin. a. Immunoglobulin G (IgG). (1) Major immunoglobulin of serum
and interstitial fluid.
(2) Provides immunity against bacterial and viral pathogens.
,RNC INFECTIOUS DISEASES QUESTIONS AND ANSWERS UPDATED
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
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(3) Placental transfer to the fetus is either an active or a passive process.
(4) Increases gradually until 40 weeks of gestation (majority is passed in the third trimester).
(5) Decreased levels in preterm infants, proportional to their gestational age.
(6) Decreased levels in postmature and small for gestational-age infants, suggesting inhibition
of transfer with placental damage.
b. Immunoglobulin M (IgM). (1) Does not cross the placental barrier.
(2) Synthesis begins early in fetal life, with detectable levels at approximately 30 weeks of
gestation.
(3) Levels may increase (>20 mg/ml) with intrauterine infection.
(4) Serum levels rapidly increase after birth.
c. Immunoglobulin A (IgA). (1) Is the most common immunoglobulin in the gastrointestinal and
respiratory tracts and is secreted in human colostrum and human milk.
(2) Does not cross the placental barrier.
(3) Intrauterine synthesis is minimal in an uninfected fetus.
, RNC INFECTIOUS DISEASES QUESTIONS AND ANSWERS UPDATED
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
CORRECT VERIFIED/DETAILED BEST RATED A+ FOR SUCCESS
(4) Does not beco
Cellular Immunity - CORRECT ANSWERS 1. Specific cellular immunity is mediated by T
lymphocytes, which enhance the efficiency of the phagocytic responses. a. T lymphocytes
migrate to the thymus, where they begin differentiation (see Fig. 32-1).
b. They are activated by antigens to which they have become sensitized and subsequently
become memory or activated T cells. However, they must be "processed" and presented on the
surface of antigen-presenting cells (i.e., macrophages and monocytes). (1) Memory cells
respond at a later time to the same antigen.
(2) There are three types of activated T cells. (a) Cytotoxic: kill foreign or virus-infected cells.
(b) Helper: enable B or T cells to respond to antigens and activate macrophages.
(c) Suppressor: repress responses of specific T and B lymphocytes to antigens.
(3) T lymphocytes modify the behavior of phagocytic cells, produce a variety of cytokines, and
increase their antimicrobial activity.
(4) Depressed T-cell function may occur as a consequence of neonatal viral infection,
hyperbilirubinemia, corticosteroid therapy, or maternal medications taken late in pregnancy.
2. Nonspecific cellular immunity is an inflammatory response involving phagocytosis and
includes neutrophils, monocytes, and complement. Neutrophilic cell invasion and platelet
aggregation are aided by the activation of the three important plasma protein systems (the
complement, clotting, and kinin systems) and immunoglobulins. Additionally, some host cells
produce soluble factors that contribute to defenses by affecting other neighboring cells. These
factors are known as cytokines and include interleukins, interferons, and other proteins.
Cytokines are multifunctional proteins, often referred to as "hormones of the immune system."
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
CORRECT VERIFIED/DETAILED BEST RATED A+ FOR SUCCESS
Host defense mechanisms - CORRECT ANSWERS Overall functions of the immune system.
a. Defense—resistance to infection by microorganisms.
b. Homeostasis—removal of worn-out cells.
c. Surveillance—perception and destruction of mutant cells.
2. Components of the immune system. a. The nonspecific mechanisms, which include
phagocytosis, the inflammatory response, and several amplification systems including
complement, coagulation, and kinin systems.
b. The specific immune responses, which consist of cell-mediated (T cell) and humoral (B cell)
systems. (1) Both are interdependent and interrelated; for example, the activation of the
complement system by immunoglobulins (IgM and IgG), or the production of chemotactic
factors and other lymphokines, plays a significant role in the whole inflammatory response.
(2) Nonspecific immune mechanisms—function without prior exposure, identified early in
gestation, functional development at 32 to 33 weeks.
c. Embryologic development (Table 32-1). (1) The maturation of specific immune responses
begins in utero during the 7th to the 12th weeks of gestation.
(2) Progenitor cells (stem cells) are initially located in the yolk sac, fetal liver, and bone marrow
of the developing embryo.
d. Depending on the type of microchemical environment surrounding the tissue, the stem cells
will differentiate along at least two pathways: (1) The hematopoietic.
,RNC INFECTIOUS DISEASES QUESTIONS AND ANSWERS UPDATED
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
CORRECT VERIFIED/DETAILED BEST RATED A+ FOR SUCCESS
(2) The lymphopoietic. (a) The lymphopoietic system develops along two independent
pathways leading to morphologically and functionally distinct populations of immune systems:
(i) The thymus-derived or T system of cell-mediated immunity whose principal effector cells are
the T lymphocytes.
(ii) The bursal-dependent or B system of humoral or antibody-mediated immunity, which is
displayed by the B lymphocytes.
(3) The thymus gland is derived from epithelium of
Humoral Immunity - CORRECT ANSWERS 1. Immunoglobulin (McCance and Huether, 2002;
Polin et al., 2001).
a. Humoral immunity is a specific antibody-mediated response that functions most effectively if
there has been previous exposure.
b. Antibodies are derived from B cells, which have been activated by T cells and antigens (Fig.
32-1).
(1) B cells mature and are stored in lymph tissue and bone marrow.
(2) B cells also produce memory cells that recognize antigens on subsequent exposures and
initiate an antibody response.
(3) Antibody functions include: (a) Recognition of bacterial antigens.
(b) Neutralization or opsonization of foreign substances, rendering them susceptible to
phagocytosis.
2. Types of immunoglobulin. a. Immunoglobulin G (IgG). (1) Major immunoglobulin of serum
and interstitial fluid.
(2) Provides immunity against bacterial and viral pathogens.
,RNC INFECTIOUS DISEASES QUESTIONS AND ANSWERS UPDATED
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
CORRECT VERIFIED/DETAILED BEST RATED A+ FOR SUCCESS
(3) Placental transfer to the fetus is either an active or a passive process.
(4) Increases gradually until 40 weeks of gestation (majority is passed in the third trimester).
(5) Decreased levels in preterm infants, proportional to their gestational age.
(6) Decreased levels in postmature and small for gestational-age infants, suggesting inhibition
of transfer with placental damage.
b. Immunoglobulin M (IgM). (1) Does not cross the placental barrier.
(2) Synthesis begins early in fetal life, with detectable levels at approximately 30 weeks of
gestation.
(3) Levels may increase (>20 mg/ml) with intrauterine infection.
(4) Serum levels rapidly increase after birth.
c. Immunoglobulin A (IgA). (1) Is the most common immunoglobulin in the gastrointestinal and
respiratory tracts and is secreted in human colostrum and human milk.
(2) Does not cross the placental barrier.
(3) Intrauterine synthesis is minimal in an uninfected fetus.
, RNC INFECTIOUS DISEASES QUESTIONS AND ANSWERS UPDATED
2024/2025 A COMPLETE EXAM SOLUTION ALL ANSWERS 100%
CORRECT VERIFIED/DETAILED BEST RATED A+ FOR SUCCESS
(4) Does not beco
Cellular Immunity - CORRECT ANSWERS 1. Specific cellular immunity is mediated by T
lymphocytes, which enhance the efficiency of the phagocytic responses. a. T lymphocytes
migrate to the thymus, where they begin differentiation (see Fig. 32-1).
b. They are activated by antigens to which they have become sensitized and subsequently
become memory or activated T cells. However, they must be "processed" and presented on the
surface of antigen-presenting cells (i.e., macrophages and monocytes). (1) Memory cells
respond at a later time to the same antigen.
(2) There are three types of activated T cells. (a) Cytotoxic: kill foreign or virus-infected cells.
(b) Helper: enable B or T cells to respond to antigens and activate macrophages.
(c) Suppressor: repress responses of specific T and B lymphocytes to antigens.
(3) T lymphocytes modify the behavior of phagocytic cells, produce a variety of cytokines, and
increase their antimicrobial activity.
(4) Depressed T-cell function may occur as a consequence of neonatal viral infection,
hyperbilirubinemia, corticosteroid therapy, or maternal medications taken late in pregnancy.
2. Nonspecific cellular immunity is an inflammatory response involving phagocytosis and
includes neutrophils, monocytes, and complement. Neutrophilic cell invasion and platelet
aggregation are aided by the activation of the three important plasma protein systems (the
complement, clotting, and kinin systems) and immunoglobulins. Additionally, some host cells
produce soluble factors that contribute to defenses by affecting other neighboring cells. These
factors are known as cytokines and include interleukins, interferons, and other proteins.
Cytokines are multifunctional proteins, often referred to as "hormones of the immune system."
