NR 507 Exam 4 Actual Exam V1 | NR 507 Advanced Pathophysiology
(NR507 Exam 4) [PDF] | Chamberlain University
1. A 65-year-old patient presents with sudden right-sided weakness and difficulty speaking. A
CT scan confirms an ischemic stroke in the left middle cerebral artery. What is the
pathophysiological significance of the ‘ischemic penumbra’ in this scenario?
A. It represents the area of irreversible necrotic cell death.
B. It refers to the focal area of hemorrhage within the infarcted tissue.
C. It is the area where vasogenic edema is most severe and non-responsive to treatment.
D. It is the zone of minimally perfused tissue surrounding the core that is potentially
salvageable.
Answer: D
Rationale: The ischemic penumbra consists of tissue that is under-perfused but has not yet
undergone complete infarction. This zone is the primary target for clinical interventions
such as thrombolysis or mechanical thrombectomy. Timely restoration of blood flow can
prevent these cells from progressing to necrosis.
2. A patient with a traumatic brain injury is monitored for increased intracranial pressure
(ICP). Which compensatory mechanism is described by the Monro-Kellie doctrine?
A. Increased cerebral blood flow to offset rising metabolic demands.
B. Decrease in systemic blood pressure to reduce cerebral perfusion.
C. Rapid proliferation of glial cells to stabilize the blood-brain barrier.
D. Displacement of cerebrospinal fluid into the spinal subarachnoid space.
Answer: D
Rationale: The Monro-Kellie doctrine states that the cranial vault is a fixed volume
containing brain tissue, blood, and CSF. When the volume of one component increases, the
others must decrease to maintain normal pressure. Displacement of CSF or venous blood
out of the cranium is the most immediate compensatory response to rising ICP.
3. What is the primary neurochemical mechanism underlying the initiation of a seizure?
A. Hyper-responsiveness of the parasympathetic nervous system during stress.
B. Complete depletion of dopamine within the basal ganglia structures.
C. An imbalance characterized by excessive glutamate activity and insufficient GABA
inhibition.
D. Chronic accumulation of beta-amyloid plaques inhibiting synaptic transmission.
,Answer: C
Rationale: Seizures result from a paroxysmal, high-frequency discharge of neurons due to
an imbalance in excitatory and inhibitory influences. Glutamate acts as the primary
excitatory neurotransmitter that facilitates depolarization, while GABA serves as the
primary inhibitory neurotransmitter. When GABA-mediated inhibition fails or glutamate-
mediated excitation is excessive, synchronous neuronal firing occurs.
4. In Parkinson’s disease, the loss of dopaminergic neurons in the substantia nigra leads to
which pathophysiological state?
A. Increased inhibition of the motor cortex due to basal ganglia dysfunction.
B. Overstimulation of the motor cortex by the thalamus.
C. Excessive production of acetylcholine at the neuromuscular junction.
D. Inhibition of the spinal reflex arc in the lower motor neurons.
Answer: A
Rationale: Dopamine normally inhibits the output of the striatum, which in turn reduces
the inhibitory signals sent to the thalamus. The loss of dopamine leads to an over-activity of
the indirect pathway and under-activity of the direct pathway, resulting in excessive
inhibition of the thalamus. This leads to the characteristic motor symptoms such as
bradykinesia and rigidity.
5. A 72-year-old female is diagnosed with Alzheimer’s disease. Pathologically, what is the role
of the tau protein in this condition?
A. Tau protein forms extracellular plaques that disrupt cell-to-cell signaling.
B. It is a protective protein that increases in response to vascular inflammation.
C. Tau protein acts as a prion that spreads infection throughout the meninges.
D. Hyperphosphorylated tau protein forms intracellular neurofibrillary tangles that disrupt
axonal transport.
Answer: D
Rationale: In Alzheimer’s disease, tau protein undergoes hyperphosphorylation, causing it
to detach from microtubules and aggregate. These aggregates form neurofibrillary tangles
within the cytoplasm of neurons, leading to cellular dysfunction and eventual death. This
process is distinct from the extracellular accumulation of amyloid-beta plaques.
6. Multiple Sclerosis (MS) is primarily characterized by which immunologic process?
A. Type I hypersensitivity reaction to environmental allergens.
B. Type IV cell-mediated hypersensitivity causing demyelination in the central nervous
system.
, C. Type III immune complex deposition in the peripheral nerve roots.
D. Excessive production of antibodies against the acetylcholine receptor.
Answer: B
Rationale: Multiple Sclerosis is an autoimmune disorder where T-cells become sensitized
to myelin proteins and cross the blood-brain barrier. These T-cells, along with
macrophages, orchestrate an inflammatory attack on the myelin sheath of CNS neurons.
This leads to the formation of sclerotic plaques and the interruption of nerve impulse
conduction.
7. A patient presents with ptosis and diplopia that worsens throughout the day. If
Myasthenia Gravis is suspected, what is the underlying pathophysiology?
A. Segmental demyelination of peripheral nerves by Macrophages.
B. Destruction of upper and lower motor neurons by oxidative stress.
C. Autoantibody-mediated destruction of nicotinic acetylcholine receptors at the
postsynaptic membrane.
D. Inadequate release of acetylcholine from the presynaptic terminal.
Answer: C
Rationale: Myasthenia Gravis is a Type II hypersensitivity disorder where IgG antibodies
bind to and destroy acetylcholine receptors at the neuromuscular junction. This reduces
the number of available receptors, making it difficult for nerve impulses to trigger muscle
contraction. Fatigue increases with repetitive use as acetylcholine stores are temporarily
depleted.
8. Amyotrophic Lateral Sclerosis (ALS) is distinct from other neurodegenerative diseases
because it affects:
A. Only the sensory neurons in the dorsal root ganglia.
B. The myelin sheath of the peripheral nerves only.
C. Both upper and lower motor neurons without affecting sensory or cognitive function in
most cases.
D. The cognitive centers of the frontal lobe exclusively.
Answer: C
Rationale: ALS involves the progressive degeneration and death of both upper motor
neurons in the cerebral cortex and lower motor neurons in the brainstem and spinal cord.
Because it targets motor pathways specifically, sensory and autonomic functions usually
remain intact. The loss of these neurons leads to progressive muscle atrophy, weakness,
and eventually respiratory failure.
(NR507 Exam 4) [PDF] | Chamberlain University
1. A 65-year-old patient presents with sudden right-sided weakness and difficulty speaking. A
CT scan confirms an ischemic stroke in the left middle cerebral artery. What is the
pathophysiological significance of the ‘ischemic penumbra’ in this scenario?
A. It represents the area of irreversible necrotic cell death.
B. It refers to the focal area of hemorrhage within the infarcted tissue.
C. It is the area where vasogenic edema is most severe and non-responsive to treatment.
D. It is the zone of minimally perfused tissue surrounding the core that is potentially
salvageable.
Answer: D
Rationale: The ischemic penumbra consists of tissue that is under-perfused but has not yet
undergone complete infarction. This zone is the primary target for clinical interventions
such as thrombolysis or mechanical thrombectomy. Timely restoration of blood flow can
prevent these cells from progressing to necrosis.
2. A patient with a traumatic brain injury is monitored for increased intracranial pressure
(ICP). Which compensatory mechanism is described by the Monro-Kellie doctrine?
A. Increased cerebral blood flow to offset rising metabolic demands.
B. Decrease in systemic blood pressure to reduce cerebral perfusion.
C. Rapid proliferation of glial cells to stabilize the blood-brain barrier.
D. Displacement of cerebrospinal fluid into the spinal subarachnoid space.
Answer: D
Rationale: The Monro-Kellie doctrine states that the cranial vault is a fixed volume
containing brain tissue, blood, and CSF. When the volume of one component increases, the
others must decrease to maintain normal pressure. Displacement of CSF or venous blood
out of the cranium is the most immediate compensatory response to rising ICP.
3. What is the primary neurochemical mechanism underlying the initiation of a seizure?
A. Hyper-responsiveness of the parasympathetic nervous system during stress.
B. Complete depletion of dopamine within the basal ganglia structures.
C. An imbalance characterized by excessive glutamate activity and insufficient GABA
inhibition.
D. Chronic accumulation of beta-amyloid plaques inhibiting synaptic transmission.
,Answer: C
Rationale: Seizures result from a paroxysmal, high-frequency discharge of neurons due to
an imbalance in excitatory and inhibitory influences. Glutamate acts as the primary
excitatory neurotransmitter that facilitates depolarization, while GABA serves as the
primary inhibitory neurotransmitter. When GABA-mediated inhibition fails or glutamate-
mediated excitation is excessive, synchronous neuronal firing occurs.
4. In Parkinson’s disease, the loss of dopaminergic neurons in the substantia nigra leads to
which pathophysiological state?
A. Increased inhibition of the motor cortex due to basal ganglia dysfunction.
B. Overstimulation of the motor cortex by the thalamus.
C. Excessive production of acetylcholine at the neuromuscular junction.
D. Inhibition of the spinal reflex arc in the lower motor neurons.
Answer: A
Rationale: Dopamine normally inhibits the output of the striatum, which in turn reduces
the inhibitory signals sent to the thalamus. The loss of dopamine leads to an over-activity of
the indirect pathway and under-activity of the direct pathway, resulting in excessive
inhibition of the thalamus. This leads to the characteristic motor symptoms such as
bradykinesia and rigidity.
5. A 72-year-old female is diagnosed with Alzheimer’s disease. Pathologically, what is the role
of the tau protein in this condition?
A. Tau protein forms extracellular plaques that disrupt cell-to-cell signaling.
B. It is a protective protein that increases in response to vascular inflammation.
C. Tau protein acts as a prion that spreads infection throughout the meninges.
D. Hyperphosphorylated tau protein forms intracellular neurofibrillary tangles that disrupt
axonal transport.
Answer: D
Rationale: In Alzheimer’s disease, tau protein undergoes hyperphosphorylation, causing it
to detach from microtubules and aggregate. These aggregates form neurofibrillary tangles
within the cytoplasm of neurons, leading to cellular dysfunction and eventual death. This
process is distinct from the extracellular accumulation of amyloid-beta plaques.
6. Multiple Sclerosis (MS) is primarily characterized by which immunologic process?
A. Type I hypersensitivity reaction to environmental allergens.
B. Type IV cell-mediated hypersensitivity causing demyelination in the central nervous
system.
, C. Type III immune complex deposition in the peripheral nerve roots.
D. Excessive production of antibodies against the acetylcholine receptor.
Answer: B
Rationale: Multiple Sclerosis is an autoimmune disorder where T-cells become sensitized
to myelin proteins and cross the blood-brain barrier. These T-cells, along with
macrophages, orchestrate an inflammatory attack on the myelin sheath of CNS neurons.
This leads to the formation of sclerotic plaques and the interruption of nerve impulse
conduction.
7. A patient presents with ptosis and diplopia that worsens throughout the day. If
Myasthenia Gravis is suspected, what is the underlying pathophysiology?
A. Segmental demyelination of peripheral nerves by Macrophages.
B. Destruction of upper and lower motor neurons by oxidative stress.
C. Autoantibody-mediated destruction of nicotinic acetylcholine receptors at the
postsynaptic membrane.
D. Inadequate release of acetylcholine from the presynaptic terminal.
Answer: C
Rationale: Myasthenia Gravis is a Type II hypersensitivity disorder where IgG antibodies
bind to and destroy acetylcholine receptors at the neuromuscular junction. This reduces
the number of available receptors, making it difficult for nerve impulses to trigger muscle
contraction. Fatigue increases with repetitive use as acetylcholine stores are temporarily
depleted.
8. Amyotrophic Lateral Sclerosis (ALS) is distinct from other neurodegenerative diseases
because it affects:
A. Only the sensory neurons in the dorsal root ganglia.
B. The myelin sheath of the peripheral nerves only.
C. Both upper and lower motor neurons without affecting sensory or cognitive function in
most cases.
D. The cognitive centers of the frontal lobe exclusively.
Answer: C
Rationale: ALS involves the progressive degeneration and death of both upper motor
neurons in the cerebral cortex and lower motor neurons in the brainstem and spinal cord.
Because it targets motor pathways specifically, sensory and autonomic functions usually
remain intact. The loss of these neurons leads to progressive muscle atrophy, weakness,
and eventually respiratory failure.
