NURS 231 Module 3 Exam Pathophysiology: 100%
Verified Questions & Answers
1) Explain the challenges of diagnosing autoimmune disorders.
• Nonspecific/overlapping symptoms: Fatigue, arthralgias, rashes, low-grade
fevers overlap with infections, malignancy, or stress.
• Waxing/waning course: Flares and remissions obscure patterns; labs can
look “normal” between flares.
• Multisystem involvement: One patient may have skin, renal, hematologic,
and neuro findings, which fragments the picture across specialties.
• No single gold-standard test: Diagnosis relies on clinical criteria + labs (ANA,
ENA panel, anti-dsDNA, RF/CCP), imaging, sometimes biopsy. Serologies can
be positive in healthy people (e.g., low-titer ANA).
• Overlap syndromes & mimics: Mixed connective tissue disease; drug-
induced autoimmunity; infections (e.g., hepatitis) can mimic.
• Genetic + environmental triggers: Penetrance is variable; the same HLA risk
doesn’t always produce disease.
2) Which type of immunity is characterized by the development of a specific
response to an antigen?
Correct:
b) Adaptive immunity — Antigen-specific B/T responses with memory.
Why others are wrong:
a) Innate = rapid, non-specific barriers/cells (skin, neutrophils, NK).
c) Autoimmunity = pathology (loss of self-tolerance), not a normal “type” of
immunity.
, d) Active immunity describes how immunity is acquired (infection/vaccine),
not whether it’s specific or innate/adaptive (though active immunity is generally
adaptive, the tested concept is “adaptive”).
3) What allows the lymphocyte to differentiate between self and foreign
molecules?
Correct:
c) Major histocompatibility complex (MHC) molecule — Presents peptide to TCR;
self vs. non-self discrimination hinges on self-MHC recognition.
a) Antigen-presenting cells (APCs) present via MHC; they’re the cells, not the
molecular mechanism.
b) Regulatory cells suppress responses; they don’t perform recognition.
d) Effector cells carry out killing/antibody secretion, not discrimination.
4) T-lymphocytes produce what type of immunity?
Answer:
Cell-mediated immunity. CD8+ kill infected/tumor cells; CD4+ coordinate
responses. (Contrast: B cells → humoral/antibody-mediated.)
5) Which immunoglobulin passes immune factors from the mother to the fetus?
Correct:
c) IgG — Crosses placenta via FcRn, protecting neonate for months.
Why others are wrong:
a) IgM pentamer—too large to cross placenta.
b) IgA is in breast milk (mucosal protection), not transplacental.
Verified Questions & Answers
1) Explain the challenges of diagnosing autoimmune disorders.
• Nonspecific/overlapping symptoms: Fatigue, arthralgias, rashes, low-grade
fevers overlap with infections, malignancy, or stress.
• Waxing/waning course: Flares and remissions obscure patterns; labs can
look “normal” between flares.
• Multisystem involvement: One patient may have skin, renal, hematologic,
and neuro findings, which fragments the picture across specialties.
• No single gold-standard test: Diagnosis relies on clinical criteria + labs (ANA,
ENA panel, anti-dsDNA, RF/CCP), imaging, sometimes biopsy. Serologies can
be positive in healthy people (e.g., low-titer ANA).
• Overlap syndromes & mimics: Mixed connective tissue disease; drug-
induced autoimmunity; infections (e.g., hepatitis) can mimic.
• Genetic + environmental triggers: Penetrance is variable; the same HLA risk
doesn’t always produce disease.
2) Which type of immunity is characterized by the development of a specific
response to an antigen?
Correct:
b) Adaptive immunity — Antigen-specific B/T responses with memory.
Why others are wrong:
a) Innate = rapid, non-specific barriers/cells (skin, neutrophils, NK).
c) Autoimmunity = pathology (loss of self-tolerance), not a normal “type” of
immunity.
, d) Active immunity describes how immunity is acquired (infection/vaccine),
not whether it’s specific or innate/adaptive (though active immunity is generally
adaptive, the tested concept is “adaptive”).
3) What allows the lymphocyte to differentiate between self and foreign
molecules?
Correct:
c) Major histocompatibility complex (MHC) molecule — Presents peptide to TCR;
self vs. non-self discrimination hinges on self-MHC recognition.
a) Antigen-presenting cells (APCs) present via MHC; they’re the cells, not the
molecular mechanism.
b) Regulatory cells suppress responses; they don’t perform recognition.
d) Effector cells carry out killing/antibody secretion, not discrimination.
4) T-lymphocytes produce what type of immunity?
Answer:
Cell-mediated immunity. CD8+ kill infected/tumor cells; CD4+ coordinate
responses. (Contrast: B cells → humoral/antibody-mediated.)
5) Which immunoglobulin passes immune factors from the mother to the fetus?
Correct:
c) IgG — Crosses placenta via FcRn, protecting neonate for months.
Why others are wrong:
a) IgM pentamer—too large to cross placenta.
b) IgA is in breast milk (mucosal protection), not transplacental.
