WGU D115 EXAM 2025/2026 QUESTIONS
AND ANSWERS 100% PASS.
What are the 3 layers of human defense? What happens during each? - ANS Physical- protect
against damage and infection are composed of tightly associated epithelial cells including those
of the skin and of the membranous sheets lining the gastrointestinal, genitourinary, and
respiratory tracts. Mechanical- "washing" the surfaces (sloughing off of dead skin, vomiting,
urination, coughing). Biochemical barriers- secrets substances meant to trap of destroy
microorganisms. (Mucus, sweat, saliva, tears, sebaceous glands, and earwax).
What is the second line of defense and the process? - ANS Inflammatory response- rapid and
nonspecific, protective response to cellular injury from any cause. It can occur only in
vascularized tissue.
How do acute and chronic inflammation differ? - ANS Acute- Short duration, 8-10 days from
onset to healing. The three systemic changes associated with the acute inflammatory response
are fever, leukocytosis, and plasma protein synthesis. Chronic inflammation- can be a
continuation of acute inflammation that last 2 weeks or longer. It can also occur as a distinct
process without much preceding acute inflammation.
What are the phases of wound healing and the process that takes place during each? -
ANS Phase 1- Inflammation- includes coagulation and the infiltration of cells that participate
in wound healing, including platelets, neutrophils, and macrophages. Phase 2- Proliferation and
New Tissue Formation (Reconstruction)- wound begins to heal. This stage begins 3-4 days after
injury and continues for as long as 2 weeks. Phase 3- Remodeling and Maturation- phase for
recovering normal tissue structure that can persist for years
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, How does the inflammatory response differ in neonates? - ANS Neonates often have
transiently depressed inflammatory function, particularly neutrophil chemotaxis and alternative
complement activity.
How and why does aging affect innate immunity? - ANS Aging alters the tissue
microenvironment and macrophage function with changes in wound healing neoangiogenesis
and fibrosis.
What is the third line of defense and the process that takes place? - ANS Adaptive immunity
(immune response or immunity)- the third line of defense in the human body. Consists of
lymphocytes and serum proteins called antibodies. - Secondary responder-augments the initial
defenses against infection and provides long term security against re-infection. - B cells-
humeral can kill free floating pathogens - T cells- cell - mediated- can kill pathogens hiding inside
cells.
How and why does the neonate have a poorly developed immune response? - ANS The
human neonate has a poorly developed immune response, particularly in the production of IgG.
The fetus and neonate are protected in utero and during the first few post-natal months by
maternal antibody that was actively transported across the placenta.
What terms are collectively known as hypersensitivity reactions? - ANS Allergy,
autoimmunity, and alloimmunity are collectively known as hypersensitivity reactions.
Hypersensitivity Response I - IgE mediated- primary cause of common allergies. Binds with mast
cells which release histamine. (initiates allergic reaction). Histamine release leads to bronchial
smooth muscle contraction, bronchoconstriction, and immune response II- tissue specific-
wrong blood type administered or hemolytic disease of the newborn. Complement pathway
activated III- Immune complex mediated IV- cell mediated - graft rejection
What are some causes of autoimmune diseases? - ANS Autoimmune disease can be caused
by the exposure of a previously sequestered antigen, the development of a neoantigen, the
complications of infectious disease, the emergence of a forbidden clone of lymphocytes, or the
consequence of ineffective peripheral tolerance. The mechanisms for imitation of autoimmune
diseases may already be within humans.
What are some examples of alloimmune disorders? And why do these occur? -
ANS Alloimmunity is the immune systems reaction against antigens on the tissues of other
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
AND ANSWERS 100% PASS.
What are the 3 layers of human defense? What happens during each? - ANS Physical- protect
against damage and infection are composed of tightly associated epithelial cells including those
of the skin and of the membranous sheets lining the gastrointestinal, genitourinary, and
respiratory tracts. Mechanical- "washing" the surfaces (sloughing off of dead skin, vomiting,
urination, coughing). Biochemical barriers- secrets substances meant to trap of destroy
microorganisms. (Mucus, sweat, saliva, tears, sebaceous glands, and earwax).
What is the second line of defense and the process? - ANS Inflammatory response- rapid and
nonspecific, protective response to cellular injury from any cause. It can occur only in
vascularized tissue.
How do acute and chronic inflammation differ? - ANS Acute- Short duration, 8-10 days from
onset to healing. The three systemic changes associated with the acute inflammatory response
are fever, leukocytosis, and plasma protein synthesis. Chronic inflammation- can be a
continuation of acute inflammation that last 2 weeks or longer. It can also occur as a distinct
process without much preceding acute inflammation.
What are the phases of wound healing and the process that takes place during each? -
ANS Phase 1- Inflammation- includes coagulation and the infiltration of cells that participate
in wound healing, including platelets, neutrophils, and macrophages. Phase 2- Proliferation and
New Tissue Formation (Reconstruction)- wound begins to heal. This stage begins 3-4 days after
injury and continues for as long as 2 weeks. Phase 3- Remodeling and Maturation- phase for
recovering normal tissue structure that can persist for years
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, How does the inflammatory response differ in neonates? - ANS Neonates often have
transiently depressed inflammatory function, particularly neutrophil chemotaxis and alternative
complement activity.
How and why does aging affect innate immunity? - ANS Aging alters the tissue
microenvironment and macrophage function with changes in wound healing neoangiogenesis
and fibrosis.
What is the third line of defense and the process that takes place? - ANS Adaptive immunity
(immune response or immunity)- the third line of defense in the human body. Consists of
lymphocytes and serum proteins called antibodies. - Secondary responder-augments the initial
defenses against infection and provides long term security against re-infection. - B cells-
humeral can kill free floating pathogens - T cells- cell - mediated- can kill pathogens hiding inside
cells.
How and why does the neonate have a poorly developed immune response? - ANS The
human neonate has a poorly developed immune response, particularly in the production of IgG.
The fetus and neonate are protected in utero and during the first few post-natal months by
maternal antibody that was actively transported across the placenta.
What terms are collectively known as hypersensitivity reactions? - ANS Allergy,
autoimmunity, and alloimmunity are collectively known as hypersensitivity reactions.
Hypersensitivity Response I - IgE mediated- primary cause of common allergies. Binds with mast
cells which release histamine. (initiates allergic reaction). Histamine release leads to bronchial
smooth muscle contraction, bronchoconstriction, and immune response II- tissue specific-
wrong blood type administered or hemolytic disease of the newborn. Complement pathway
activated III- Immune complex mediated IV- cell mediated - graft rejection
What are some causes of autoimmune diseases? - ANS Autoimmune disease can be caused
by the exposure of a previously sequestered antigen, the development of a neoantigen, the
complications of infectious disease, the emergence of a forbidden clone of lymphocytes, or the
consequence of ineffective peripheral tolerance. The mechanisms for imitation of autoimmune
diseases may already be within humans.
What are some examples of alloimmune disorders? And why do these occur? -
ANS Alloimmunity is the immune systems reaction against antigens on the tissues of other
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
