PATHOLOGY TEST BANK - PRACTICE
EXAM 1 QUESTIONS WITH COMPLETE
ANSWERS
A tissue preparation is experimentally subjected to a hypoxic environment. The cells in
this tissue begin to swell, and chromatin begins to clump in cell nuclei. ATPases are
activated, and ATP production decreases. Which of the following ions accumulating in
mitochondria and the cytosol contributes most to these findings and to eventual cell
death?
A Ca2+
B Cl−
C HCO3−
D K+
E Na+
F PO43− - Answer-.
Answer: A
Reasoning: Irreversible cellular injury is likely to occur when cytoplasmic calcium
increases. Calcium can enter cells and also accumulate in mitochondria and
endoplasmic reticulum. The excess calcium activates ATPases, phospholipases,
proteases, and endonucleases, which injure cell components. Mitochondrial
permeability is increased to release cytochrome c, which activates caspases leading to
apoptosis.
Extended reasoning: Of the other ions listed, sodium enters the cell, while potassium
diffuses out when the sodium pump fails as ATP levels fall; but this is potentially
reversible.
A 5-year-old child ingests 50 iron tablets, each with 27 mg of iron. Within 6 hours the
child develops abdominal pain and lethargy. On physical examination he is hypotensive.
Laboratory studies show metabolic acidosis. Through formation of which of the following
compounds is the cell injury in this child most likely mediated?
A Ascorbic acid
B Hemosiderin
C Hydroxyl radical
D Nitric oxide
E Superoxide dismutase - Answer-Answer: C
Reasoning: Excessive iron ingestion, particularly by a child, can overwhelm the body's
ability to bind the absorbed free iron with the transport protein transferrin. The free iron
contributes to generation of cellular free radicals via the Fenton reaction.
Extended reasoning: Ascorbic acid (vitamin C) and vitamin E both act as antioxidants to
protect against free radical injury, albeit over a long time frame. Hemosiderin is a
storage form of iron from excess local or systemic accumulation of ferritin, and by itself
does not cause cell injury until large amounts are present, as with hemochromatosis.
Nitric oxide generated within macrophages can be to kill microbes. It can be converted
,to a highly reactive peroxynitrite anion. Superoxide dismutase helps break down
superoxide anion to hydrogen peroxide, thus scavenging free radicals.
A 47-year-old man has a lung carcinoma with metastases. He receives chemotherapy.
A month later, histologic examination of a metastatic lesion shows many foci in which
individual tumor cells appear shrunken and deeply eosinophilic. Their nuclei exhibit
condensed aggregates of chromatin under the nuclear membrane. The pathologic
process affecting these shrunken tumor cells is most likely triggered by release of which
of the following substances into the cytosol?
A BCL2
B Catalase
C Cytochrome c
D Lipofuscin
E Phospholipase - Answer-Answer: C
Reasoning: This histologic picture is typical of apoptosis produced by chemotherapeutic
agents. The release of cytochrome c from the mitochondria is a key step in many forms
of apoptosis, and it leads to the activation of caspases.
Extended reasoning: BCL2 is an antiapoptotic protein that prevents cytochrome c
release and prevents caspase activation. Catalase is a scavenger of hydrogen
peroxide. Lipofuscin is a pigmented residue representing undigested cellular organelles
in autophagic vacuoles, much like old clothes in a closet. Phospholipases are activated
during necrosis and cause cell membrane damage.
An 11-year-old child falls and cuts his hand. The wound becomes infected. Bacteria
extend into the extracellular matrix around capillaries. In the inflammatory response to
this infection, which of the following cells removes the bacteria?
A B lymphocyte
B Fibroblast
C Macrophage
D Mast cell
E T lymphocyte - Answer-Answer: C
Reasoning: Macrophages in tissues derived from circulating blood monocytes are
phagocytic cells that respond to a variety of stimuli, and they represent the janitorial
crew of the body. The other cells listed are not phagocytes.
Extended reasoning: B cells can differentiate into plasma cells secreting antibodies to
neutralize infectious agents. Fibroblasts form collagen as part of a healing response.
Mast cells can release a variety of inflammatory mediators. T cells are a key part of
chronic inflammatory processes in cell-mediated immune responses.
In an experiment, bacteria are introduced into a per- fused tissue preparation.
Leukocytes leave the vasculature and migrate to the site of bacterial inoculation. The
movement of these leukocytes is most likely to be mediated by which of the following
substances?
A Bradykinin
B Chemokines
C Complement C3a
, D Histamine
E Prostaglandins - Answer-Answer: B
Reasoning: Chemokines include many molecules that are chemotactic for neutrophils,
eosinophils, lymphocytes, monocytes, and basophils.
Extended reasoning: Bradykinin causes pain and increased vascular permeability.
Complement C3a causes increased vascular permeability by releasing histamine from
mast cells. Histamine causes vascular leakage. Prostaglandins have multiple actions,
but they do not cause chemotaxis.
A 5-year-old child has a history of recurrent bacterial infections, including pneumonia
and otitis media. Analysis of leukocytes collected from the peripheral blood shows a
deficiency in myeloperoxidase. A reduction in which of the following processes is the
most likely cause of this child's in- creased susceptibility to infections?
A Hydrogen peroxide (H2O2) elaboration
B Hydroxy-halide radical (HOCl-) formation
C Failure of migration resulting from complement
deficiency
D Phagocytic cell oxygen consumption
E Prostaglandin production - Answer-Answer: B
Reasoning: Myeloperoxidase is present in the azurophilic granules of neutrophils. It
converts H2O2 into HOCl-, a powerful oxidant and antimicrobial agent. Degranulation
occurs as phagolysosomes are formed with engulfed bacteria in phagocytic vacuoles
within the neutrophil cytoplasm.
In an experiment, neutrophils collected from peripheral blood are analyzed for a "burst"
of oxygen consumption. This respiratory burst is an essential step for which of the
following events in an acute inflammatory response?
A Attachment to endothelial cells
B Generation of microbicidal activity
C Increased production in bone marrow
D Opsonization of bacteria
E Phagocytosis of bacteria - Answer-.
Answer: B
Reasoning: The respiratory, or oxidative, burst of neutrophils generates reactive oxygen
species (e.g., superoxide anion) that are important in destruction of engulfed bacteria.
Extended reasoning: Neutrophil attachment to endothelium is aided by adhesion
molecules on both the endothelium and the neutrophil surface. These molecules include
selectins and integrins. Myelopoiesis does not depend on generation of superoxide.
Bacteria are opsonized by complement C3b and IgG, allowing the bacteria to be more
readily phagocytosed.
A 4-year-old girl has had numerous infections with Staphylococcus aureus since
infancy. Genetic testing shows a defect leading to a lack of β2 integrin production.
Which of the following abnormalities of neutrophil function is most likely responsible for
these clinical symptoms?
A Decreased generation of hydroxy-halide radicals (HOCl-)
EXAM 1 QUESTIONS WITH COMPLETE
ANSWERS
A tissue preparation is experimentally subjected to a hypoxic environment. The cells in
this tissue begin to swell, and chromatin begins to clump in cell nuclei. ATPases are
activated, and ATP production decreases. Which of the following ions accumulating in
mitochondria and the cytosol contributes most to these findings and to eventual cell
death?
A Ca2+
B Cl−
C HCO3−
D K+
E Na+
F PO43− - Answer-.
Answer: A
Reasoning: Irreversible cellular injury is likely to occur when cytoplasmic calcium
increases. Calcium can enter cells and also accumulate in mitochondria and
endoplasmic reticulum. The excess calcium activates ATPases, phospholipases,
proteases, and endonucleases, which injure cell components. Mitochondrial
permeability is increased to release cytochrome c, which activates caspases leading to
apoptosis.
Extended reasoning: Of the other ions listed, sodium enters the cell, while potassium
diffuses out when the sodium pump fails as ATP levels fall; but this is potentially
reversible.
A 5-year-old child ingests 50 iron tablets, each with 27 mg of iron. Within 6 hours the
child develops abdominal pain and lethargy. On physical examination he is hypotensive.
Laboratory studies show metabolic acidosis. Through formation of which of the following
compounds is the cell injury in this child most likely mediated?
A Ascorbic acid
B Hemosiderin
C Hydroxyl radical
D Nitric oxide
E Superoxide dismutase - Answer-Answer: C
Reasoning: Excessive iron ingestion, particularly by a child, can overwhelm the body's
ability to bind the absorbed free iron with the transport protein transferrin. The free iron
contributes to generation of cellular free radicals via the Fenton reaction.
Extended reasoning: Ascorbic acid (vitamin C) and vitamin E both act as antioxidants to
protect against free radical injury, albeit over a long time frame. Hemosiderin is a
storage form of iron from excess local or systemic accumulation of ferritin, and by itself
does not cause cell injury until large amounts are present, as with hemochromatosis.
Nitric oxide generated within macrophages can be to kill microbes. It can be converted
,to a highly reactive peroxynitrite anion. Superoxide dismutase helps break down
superoxide anion to hydrogen peroxide, thus scavenging free radicals.
A 47-year-old man has a lung carcinoma with metastases. He receives chemotherapy.
A month later, histologic examination of a metastatic lesion shows many foci in which
individual tumor cells appear shrunken and deeply eosinophilic. Their nuclei exhibit
condensed aggregates of chromatin under the nuclear membrane. The pathologic
process affecting these shrunken tumor cells is most likely triggered by release of which
of the following substances into the cytosol?
A BCL2
B Catalase
C Cytochrome c
D Lipofuscin
E Phospholipase - Answer-Answer: C
Reasoning: This histologic picture is typical of apoptosis produced by chemotherapeutic
agents. The release of cytochrome c from the mitochondria is a key step in many forms
of apoptosis, and it leads to the activation of caspases.
Extended reasoning: BCL2 is an antiapoptotic protein that prevents cytochrome c
release and prevents caspase activation. Catalase is a scavenger of hydrogen
peroxide. Lipofuscin is a pigmented residue representing undigested cellular organelles
in autophagic vacuoles, much like old clothes in a closet. Phospholipases are activated
during necrosis and cause cell membrane damage.
An 11-year-old child falls and cuts his hand. The wound becomes infected. Bacteria
extend into the extracellular matrix around capillaries. In the inflammatory response to
this infection, which of the following cells removes the bacteria?
A B lymphocyte
B Fibroblast
C Macrophage
D Mast cell
E T lymphocyte - Answer-Answer: C
Reasoning: Macrophages in tissues derived from circulating blood monocytes are
phagocytic cells that respond to a variety of stimuli, and they represent the janitorial
crew of the body. The other cells listed are not phagocytes.
Extended reasoning: B cells can differentiate into plasma cells secreting antibodies to
neutralize infectious agents. Fibroblasts form collagen as part of a healing response.
Mast cells can release a variety of inflammatory mediators. T cells are a key part of
chronic inflammatory processes in cell-mediated immune responses.
In an experiment, bacteria are introduced into a per- fused tissue preparation.
Leukocytes leave the vasculature and migrate to the site of bacterial inoculation. The
movement of these leukocytes is most likely to be mediated by which of the following
substances?
A Bradykinin
B Chemokines
C Complement C3a
, D Histamine
E Prostaglandins - Answer-Answer: B
Reasoning: Chemokines include many molecules that are chemotactic for neutrophils,
eosinophils, lymphocytes, monocytes, and basophils.
Extended reasoning: Bradykinin causes pain and increased vascular permeability.
Complement C3a causes increased vascular permeability by releasing histamine from
mast cells. Histamine causes vascular leakage. Prostaglandins have multiple actions,
but they do not cause chemotaxis.
A 5-year-old child has a history of recurrent bacterial infections, including pneumonia
and otitis media. Analysis of leukocytes collected from the peripheral blood shows a
deficiency in myeloperoxidase. A reduction in which of the following processes is the
most likely cause of this child's in- creased susceptibility to infections?
A Hydrogen peroxide (H2O2) elaboration
B Hydroxy-halide radical (HOCl-) formation
C Failure of migration resulting from complement
deficiency
D Phagocytic cell oxygen consumption
E Prostaglandin production - Answer-Answer: B
Reasoning: Myeloperoxidase is present in the azurophilic granules of neutrophils. It
converts H2O2 into HOCl-, a powerful oxidant and antimicrobial agent. Degranulation
occurs as phagolysosomes are formed with engulfed bacteria in phagocytic vacuoles
within the neutrophil cytoplasm.
In an experiment, neutrophils collected from peripheral blood are analyzed for a "burst"
of oxygen consumption. This respiratory burst is an essential step for which of the
following events in an acute inflammatory response?
A Attachment to endothelial cells
B Generation of microbicidal activity
C Increased production in bone marrow
D Opsonization of bacteria
E Phagocytosis of bacteria - Answer-.
Answer: B
Reasoning: The respiratory, or oxidative, burst of neutrophils generates reactive oxygen
species (e.g., superoxide anion) that are important in destruction of engulfed bacteria.
Extended reasoning: Neutrophil attachment to endothelium is aided by adhesion
molecules on both the endothelium and the neutrophil surface. These molecules include
selectins and integrins. Myelopoiesis does not depend on generation of superoxide.
Bacteria are opsonized by complement C3b and IgG, allowing the bacteria to be more
readily phagocytosed.
A 4-year-old girl has had numerous infections with Staphylococcus aureus since
infancy. Genetic testing shows a defect leading to a lack of β2 integrin production.
Which of the following abnormalities of neutrophil function is most likely responsible for
these clinical symptoms?
A Decreased generation of hydroxy-halide radicals (HOCl-)
