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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
Answer: A
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 .
2. What are the three main components contained within the cranial cavity
according to the Monro-Kellie doctrine?
• A) Brain, Cerebrospinal Fluid (CSF), Blood
• B) Brain, Skull, Meninges
• C) Blood, CSF, Ventricles
• D) Brain, Blood, Meninges
Answer: A
,Rationale: The Monroe-Kellie doctrine states that the cranial cavity contains three main
components: brain tissue (approximately 80%), cerebrospinal fluid (CSF, approximately
10%), and blood (approximately 10%) .
3. What is the normal range for intracranial pressure (ICP)?
• A) 0–5 mmHg
• B) 0–15 mmHg
• C) 15–25 mmHg
• D) 25–35 mmHg
Answer: B
Rationale: Normal intracranial pressure is typically between 0 and 15 mmHg. A reading
of 20 mmHg or higher is considered elevated and requires immediate intervention .
4. 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 (CPP)?
• A) 45 mm Hg
• B) 115 mm Hg
• C) 65 mm Hg
• D) 90 mm Hg
Answer: C
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 .
5. 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
Answer: B
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 .
6. 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
Answer: D
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 .
7. 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