NURS 231 Module 3 Exam Questions
And Answers
/. What is innate immunity? - Answer-✅Innate immunity, also called natural immunity, is
the first line of defense. This type of defense is in place before an infection takes place
and can function immediately. It is comprised of physical, chemical, cellular, and
molecular defenses.
/.How does the skin act as a physical barrier? - Answer-✅The skin's design makes it a
strong physical barrier. It has closely packed cells in multiple layers that are
continuously being shed. Keratin covers the skin, which creates a salty, acidic
environment inhospitable to microbes. It also contains antimicrobial proteins and
lysozymes that inhibit microorganisms and help to destroy them.
/.What cells are involved in innate immunity? - Answer-✅The cells responsible for this
response include neutrophils, macrophages, dendritic cells (DC), natural killer (NK)
cells, and intraepithelial lymphocytes.
/.Describe each type of leukocyte and explain their function: - Answer-✅Neutrophils are
the most abundant in the body and are an early responder in innate immunity and use
phagocytosis to kill microbes. Eosinophils are active in parasitic infections and allergic
responses. Basophils release histamine and proteolytic enzymes. Monocytes are the
largest in size and are released from the bone marrow and mature into macrophages
and dendritic cells where they engage in the inflammatory response and phagocytize
foreign substances and cellular debris. Macrophages have a long life span, reside in the
tissues, and are the first phagocyte that organisms encounter. Neutrophils and
macrophages work together on behalf of the host's initial defense system.
/.Describe adaptive immunity: - Answer-✅Adaptive immunity, also called acquired
immunity, is the second line of defense and includes both humoral and cellular
mechanisms that respond to cell-specific substances known as antigens. Adaptive
immunity is acquired through previous exposure to infections and other foreign agents.
It can not only distinguish self from nonself but can recognize and destroy specific
foreign agents based on their different antigenic properties. This response takes more
time but is extremely effective.
/.What are antigens? - Answer-✅Antigens are present on the surface of pathogens or
other foreign substances that elicit the adaptive immune response.
, /.What are the primary cells of adaptive immunity? - Answer-✅The primary cells of the
adaptive immune system are the lymphocytes, APCs (antigen presenting cells), and
effector cells.
/.Describe B & T lymphocytes and discuss their role in immunity: - Answer-✅B
lymphocytes produce the antibodies (humoral immunity) and T lymphocytes provide the
cell-mediated immunity. B and T lymphocytes have the unique function as the only cells
to recognize specific antigens present on the surface of pathogens and to remember
them in the future.
/.What is the function of humoral immunity? - Answer-✅B lymphocytes function in
humoral immunity to produce antibodies.
/.What is the function of cellular immunity? - Answer-✅T lymphocytes make up the
cellular immunity and function to activate other T and B cells, control intracellular viral
infections, reject foreign tissue grafts, activate autoimmune processes, and activate
delayed hypersensitivity reactions.
/.What is the master regulator of the immune system? - Answer-✅CD4+ helper T cells
/.Describe the differences between active and passive immunity? - Answer-✅Active
immunity is acquired from an immune response either via vaccination or from
environmental exposure. Active immunity is long lasting but takes days to weeks after
the first exposure to fully develop a response.
Passive immunity is immunity transferred from another source. The most common
example is from mother to fetus, where the IgG antibodies are passed on either via the
placenta or breast milk or colostrum. Passive immunity is short-term protection lasting
only weeks to months.
/.What are type I hypersensitivity reactions? - Answer-✅IgE-mediated reactions that
develop quickly upon exposure to an antigen.
/.What cells are involved in type I reactions? (Know their roles.) - Answer-✅Mast cells,
basophils, and eosinophils play an important role in the development of type I reactions
because they contain the chemical mediator histamine.
/.What are type II hypersensitivity reactions? - Answer-✅Type II hypersensitivity
reactions, or cytotoxic hypersensitivity reactions, are antibody-mediated reactions. They
are mediated by IgG or IgM antibodies directed against target antigens on specific host
cell surfaces or tissues.
/.What are autoimmune disorders? - Answer-✅Autoimmune diseases occur when the
body's immune system fails to differentiate self-antigens from nonself antigens and
mounts an immunologic response against host tissues.
And Answers
/. What is innate immunity? - Answer-✅Innate immunity, also called natural immunity, is
the first line of defense. This type of defense is in place before an infection takes place
and can function immediately. It is comprised of physical, chemical, cellular, and
molecular defenses.
/.How does the skin act as a physical barrier? - Answer-✅The skin's design makes it a
strong physical barrier. It has closely packed cells in multiple layers that are
continuously being shed. Keratin covers the skin, which creates a salty, acidic
environment inhospitable to microbes. It also contains antimicrobial proteins and
lysozymes that inhibit microorganisms and help to destroy them.
/.What cells are involved in innate immunity? - Answer-✅The cells responsible for this
response include neutrophils, macrophages, dendritic cells (DC), natural killer (NK)
cells, and intraepithelial lymphocytes.
/.Describe each type of leukocyte and explain their function: - Answer-✅Neutrophils are
the most abundant in the body and are an early responder in innate immunity and use
phagocytosis to kill microbes. Eosinophils are active in parasitic infections and allergic
responses. Basophils release histamine and proteolytic enzymes. Monocytes are the
largest in size and are released from the bone marrow and mature into macrophages
and dendritic cells where they engage in the inflammatory response and phagocytize
foreign substances and cellular debris. Macrophages have a long life span, reside in the
tissues, and are the first phagocyte that organisms encounter. Neutrophils and
macrophages work together on behalf of the host's initial defense system.
/.Describe adaptive immunity: - Answer-✅Adaptive immunity, also called acquired
immunity, is the second line of defense and includes both humoral and cellular
mechanisms that respond to cell-specific substances known as antigens. Adaptive
immunity is acquired through previous exposure to infections and other foreign agents.
It can not only distinguish self from nonself but can recognize and destroy specific
foreign agents based on their different antigenic properties. This response takes more
time but is extremely effective.
/.What are antigens? - Answer-✅Antigens are present on the surface of pathogens or
other foreign substances that elicit the adaptive immune response.
, /.What are the primary cells of adaptive immunity? - Answer-✅The primary cells of the
adaptive immune system are the lymphocytes, APCs (antigen presenting cells), and
effector cells.
/.Describe B & T lymphocytes and discuss their role in immunity: - Answer-✅B
lymphocytes produce the antibodies (humoral immunity) and T lymphocytes provide the
cell-mediated immunity. B and T lymphocytes have the unique function as the only cells
to recognize specific antigens present on the surface of pathogens and to remember
them in the future.
/.What is the function of humoral immunity? - Answer-✅B lymphocytes function in
humoral immunity to produce antibodies.
/.What is the function of cellular immunity? - Answer-✅T lymphocytes make up the
cellular immunity and function to activate other T and B cells, control intracellular viral
infections, reject foreign tissue grafts, activate autoimmune processes, and activate
delayed hypersensitivity reactions.
/.What is the master regulator of the immune system? - Answer-✅CD4+ helper T cells
/.Describe the differences between active and passive immunity? - Answer-✅Active
immunity is acquired from an immune response either via vaccination or from
environmental exposure. Active immunity is long lasting but takes days to weeks after
the first exposure to fully develop a response.
Passive immunity is immunity transferred from another source. The most common
example is from mother to fetus, where the IgG antibodies are passed on either via the
placenta or breast milk or colostrum. Passive immunity is short-term protection lasting
only weeks to months.
/.What are type I hypersensitivity reactions? - Answer-✅IgE-mediated reactions that
develop quickly upon exposure to an antigen.
/.What cells are involved in type I reactions? (Know their roles.) - Answer-✅Mast cells,
basophils, and eosinophils play an important role in the development of type I reactions
because they contain the chemical mediator histamine.
/.What are type II hypersensitivity reactions? - Answer-✅Type II hypersensitivity
reactions, or cytotoxic hypersensitivity reactions, are antibody-mediated reactions. They
are mediated by IgG or IgM antibodies directed against target antigens on specific host
cell surfaces or tissues.
/.What are autoimmune disorders? - Answer-✅Autoimmune diseases occur when the
body's immune system fails to differentiate self-antigens from nonself antigens and
mounts an immunologic response against host tissues.
