,Galen NSG 3280 Exam 3 – Pathophysiology for
Nurses I (2026) Actual Q&A PDF
1. Which of the following best describes the compensatory mechanism of the Monro‑Kellie doctrine
when an intracranial mass begins to expand?
A) Displacement of cerebrospinal fluid into the spinal canal and a decrease in cerebral blood volume
B) Rapid increase in brain tissue volume to cushion the mass
C) Immediate dilation of cerebral arteries to enhance perfusion
D) Increased production of cerebrospinal fluid to buffer the pressure
Correct Answer: Displacement of cerebrospinal fluid into the spinal canal and a decrease in cerebral
blood volume
Rationale: The Monro‑Kellie doctrine states that the skull is a rigid container; when one component
(brain, blood, or CSF) increases in volume, another must decrease to maintain normal ICP. Initial
compensation occurs by shifting CSF into the spinal subarachnoid space and reducing cerebral blood
volume through vasoconstriction. The other options describe responses that would increase
intracranial volume and are not compensatory mechanisms.
2. A change in level of consciousness is the earliest and most sensitive indicator of rising intracranial
pressure because it reflects impairment of which cerebral structure?
A) Cerebellar vermis
B) Reticular activating system
C) Hypothalamic thermoregulatory center
D) Pituitary stalk
Correct Answer: Reticular activating system
Rationale: The reticular activating system (RAS) in the brainstem is responsible for maintaining
wakefulness and consciousness. Even slight increases in ICP can compress the RAS, leading to
drowsiness or confusion before other signs appear. The cerebellum, hypothalamus, and pituitary are
not the primary structures responsible for the earliest change in LOC.
,3. A patient with a traumatic brain injury has a mean arterial pressure of 90 mm Hg and an ICP of 25
mm Hg. What is the cerebral perfusion pressure?
A) 45 mm Hg
B) 115 mm Hg
C) 65 mm Hg
D) 90 mm Hg
Correct Answer: 65 mm Hg
Rationale: Cerebral perfusion pressure (CPP) is calculated as MAP minus ICP (90 – 25 = 65 mm Hg).
Normal CPP is 60–100 mm Hg. A CPP below 50 mm Hg indicates inadequate cerebral blood flow. The
other calculations are incorrect or represent components of the formula rather than the result.
4. A nurse is assessing a patient with a severe closed head injury. Which set of vital signs is most
consistent with Cushing’s triad?
A) Hypotension, tachycardia, and rapid shallow respirations
B) Bradycardia, hypotension, and Cheyne‑Stokes respirations
C) Hypertension with narrowed pulse pressure, tachycardia, and hyperventilation
D) Hypertension with widened pulse pressure, bradycardia, and irregular respirations
Correct Answer: Hypertension with widened pulse pressure, bradycardia, and irregular respirations
Rationale: Cushing’s triad is a late sign of increased ICP and brainstem compression, characterized by
systolic hypertension with a widening pulse pressure, reflex bradycardia, and irregular or depressed
respirations. Hypotension, tachycardia, or narrowed pulse pressure are not part of the classic triad.
5. Which type of intracranial hematoma results from a tear in the middle meningeal artery and may
present with a lucid interval?
A) Subdural hematoma
B) Intracerebral hematoma
, C) Subarachnoid hematoma
D) Epidural hematoma
Correct Answer: Epidural hematoma
Rationale: An epidural hematoma typically arises from arterial bleeding, most often a tear of the
middle meningeal artery associated with a temporal bone fracture. Patients may experience a brief
lucid interval followed by rapid deterioration. Subdural hematomas result from venous tearing,
intracerebral from intraparenchymal vessels, and subarachnoid from aneurysm rupture or trauma.
6. Which physiologic change is most likely to directly increase intracranial pressure in a patient with a
brain injury?
A) Hyperventilation leading to respiratory alkalosis
B) Cerebral vasodilation due to hypercapnia
C) Increased systemic vascular resistance from vasopressors
D) Decreased cerebral metabolic rate from sedation
Correct Answer: Cerebral vasodilation due to hypercapnia
Rationale: Hypercapnia causes cerebral vasodilation, which increases cerebral blood volume and
thereby raises ICP within the rigid skull. Hyperventilation causes vasoconstriction and lowers ICP.
Increased systemic vascular resistance does not directly dilate cerebral vessels, and decreased
metabolic rate tends to reduce cerebral blood flow.
7. A patient with a severe head injury is intubated. The nurse should question which intervention
because it would likely worsen ICP?
A) Elevating the head of the bed to 30 degrees
B) Maintaining a PaCO₂ of 35–45 mm Hg
C) Deliberately reducing the respiratory rate to allow gentle hypoventilation
D) Administering mannitol as ordered for osmotic diuresis
Correct Answer: Deliberately reducing the respiratory rate to allow gentle hypoventilation
Nurses I (2026) Actual Q&A PDF
1. Which of the following best describes the compensatory mechanism of the Monro‑Kellie doctrine
when an intracranial mass begins to expand?
A) Displacement of cerebrospinal fluid into the spinal canal and a decrease in cerebral blood volume
B) Rapid increase in brain tissue volume to cushion the mass
C) Immediate dilation of cerebral arteries to enhance perfusion
D) Increased production of cerebrospinal fluid to buffer the pressure
Correct Answer: Displacement of cerebrospinal fluid into the spinal canal and a decrease in cerebral
blood volume
Rationale: The Monro‑Kellie doctrine states that the skull is a rigid container; when one component
(brain, blood, or CSF) increases in volume, another must decrease to maintain normal ICP. Initial
compensation occurs by shifting CSF into the spinal subarachnoid space and reducing cerebral blood
volume through vasoconstriction. The other options describe responses that would increase
intracranial volume and are not compensatory mechanisms.
2. A change in level of consciousness is the earliest and most sensitive indicator of rising intracranial
pressure because it reflects impairment of which cerebral structure?
A) Cerebellar vermis
B) Reticular activating system
C) Hypothalamic thermoregulatory center
D) Pituitary stalk
Correct Answer: Reticular activating system
Rationale: The reticular activating system (RAS) in the brainstem is responsible for maintaining
wakefulness and consciousness. Even slight increases in ICP can compress the RAS, leading to
drowsiness or confusion before other signs appear. The cerebellum, hypothalamus, and pituitary are
not the primary structures responsible for the earliest change in LOC.
,3. A patient with a traumatic brain injury has a mean arterial pressure of 90 mm Hg and an ICP of 25
mm Hg. What is the cerebral perfusion pressure?
A) 45 mm Hg
B) 115 mm Hg
C) 65 mm Hg
D) 90 mm Hg
Correct Answer: 65 mm Hg
Rationale: Cerebral perfusion pressure (CPP) is calculated as MAP minus ICP (90 – 25 = 65 mm Hg).
Normal CPP is 60–100 mm Hg. A CPP below 50 mm Hg indicates inadequate cerebral blood flow. The
other calculations are incorrect or represent components of the formula rather than the result.
4. A nurse is assessing a patient with a severe closed head injury. Which set of vital signs is most
consistent with Cushing’s triad?
A) Hypotension, tachycardia, and rapid shallow respirations
B) Bradycardia, hypotension, and Cheyne‑Stokes respirations
C) Hypertension with narrowed pulse pressure, tachycardia, and hyperventilation
D) Hypertension with widened pulse pressure, bradycardia, and irregular respirations
Correct Answer: Hypertension with widened pulse pressure, bradycardia, and irregular respirations
Rationale: Cushing’s triad is a late sign of increased ICP and brainstem compression, characterized by
systolic hypertension with a widening pulse pressure, reflex bradycardia, and irregular or depressed
respirations. Hypotension, tachycardia, or narrowed pulse pressure are not part of the classic triad.
5. Which type of intracranial hematoma results from a tear in the middle meningeal artery and may
present with a lucid interval?
A) Subdural hematoma
B) Intracerebral hematoma
, C) Subarachnoid hematoma
D) Epidural hematoma
Correct Answer: Epidural hematoma
Rationale: An epidural hematoma typically arises from arterial bleeding, most often a tear of the
middle meningeal artery associated with a temporal bone fracture. Patients may experience a brief
lucid interval followed by rapid deterioration. Subdural hematomas result from venous tearing,
intracerebral from intraparenchymal vessels, and subarachnoid from aneurysm rupture or trauma.
6. Which physiologic change is most likely to directly increase intracranial pressure in a patient with a
brain injury?
A) Hyperventilation leading to respiratory alkalosis
B) Cerebral vasodilation due to hypercapnia
C) Increased systemic vascular resistance from vasopressors
D) Decreased cerebral metabolic rate from sedation
Correct Answer: Cerebral vasodilation due to hypercapnia
Rationale: Hypercapnia causes cerebral vasodilation, which increases cerebral blood volume and
thereby raises ICP within the rigid skull. Hyperventilation causes vasoconstriction and lowers ICP.
Increased systemic vascular resistance does not directly dilate cerebral vessels, and decreased
metabolic rate tends to reduce cerebral blood flow.
7. A patient with a severe head injury is intubated. The nurse should question which intervention
because it would likely worsen ICP?
A) Elevating the head of the bed to 30 degrees
B) Maintaining a PaCO₂ of 35–45 mm Hg
C) Deliberately reducing the respiratory rate to allow gentle hypoventilation
D) Administering mannitol as ordered for osmotic diuresis
Correct Answer: Deliberately reducing the respiratory rate to allow gentle hypoventilation
