NU 545 Unit 2 ACTUAL EXAM | QUESTIONS AND ANSWERS | VERIFIED
AND WELL DETAILED ANSWERS GRADED A+| LATEST EXAM
Review the anatomy of the brain. Which portion is responsible for keeping you
awake, controlling thought, speech, emotions and behavior, maintaining balance
and posture? - CORRECT ANSWER- The reticular formation is a large network
of diffuse nuclei that connect the brainstem to the cortex and control vital reflexes.
It is essential for maintaining wakefulness and is referred to as the reticular
activating system. Some nuclei within the reticular formation support specific
motor movements, such as balance and posture (p448). The cerebellum is
responsible for maintaining balance and posture (p452). The prefrontal area is
responsible for the elaboration of thought (pg 449). The Broca speech area is on
the inferior frontal gyrus (Brodmann 44, 45). It is usually on the left hemisphere
and is responsible for motor aspects of speech. Broca Area in the inferior frontal
lobe (Brodmann areas 44, 45) is an important center for speech and language
processing. This area, rostral to the inferior edge of the premotor area (Brodmann
area 6). Injury to this area results in difficulty forming or inability to for words
(expressive aphasia or dysphasia). Wernicke (posterior Brodmann 22) and adjacent
portions of the parietal lobe are a sensory speech area, responsible for reception
and interpretation of speech (aphasia/dysphasia). Insula (insular lobe) between
hemispheres temporal and frontal lobes, processes emotional information (pg 450).
The basal ganglia nuclei are important for emotional functions (pg 451). Cerebrum
> forebrain/hindbrain
Broca's area = difficulty writing and finding words, See chart 17.10 (p523)
Know the function of the arachnoid villi. - CORRECT ANSWER- The arachnoid
villi protrude from the arachnoid space, through the dura mater, and lie within the
blood flow of the venous sinuses. The villi function as one-way valves directing
CSF outflow into the blood but preventing blood flow into the subarachnoid space.
Thus CSF is formed from the blood and, after circulating throughout the CNS, it
returns to the blood. Absorbs CSF (pg 459)
Where is the primary defect in Parkinson's disease and Huntington's? -
CORRECT ANSWER- Extrapyramidal system; controls motor system
(involuntary movement) (pg 451). Substantia nigra (of the midbrain) synthesizes
dopamine. The dysfunction of dopamine neurons is associated with PD and
Huntington's
What is the function of the CSF? Where is it produced? Where is it absorbed? -
CORRECT ANSWER- Cerebrospinal fluid (CSF) is a clear, colorless fluid
,similar to blood plasma and interstitial fluid. The intracranial and spinal cord
structures float in CSF and are thereby partially protected from jolts and blows.
The buoyant properties of the CSF also prevent the brain from tugging on
meninges, nerve roots, and blood vessels. Appx 600mL is produced daily (457).
Ependymal cells in the choroid plexuses are the structures that produce CSF; they
arise from the pia mater. The arachnoid villi reabsorb the CSF (p458)
Review blood flow to the brain. - CORRECT ANSWER- The brain receives
approximately 20% of the cardiac output, or 800 to 1000 mL of blood flow per
minute. Autoregulated to maintain a stable flow during fluctuating perfusion
pressures. Carbon dioxide serves as a primary regulator for blood flow within the
CNS. It is a potent vasodilator in the CNS, and its effects ensure an adequate blood
supply. The brain derives its arterial supply from the internal carotid arteries
(anterior circulation) and the vertebral arteries (posterior circulation) (Fig. 15.20).
The internal carotid arteries supply a proportionately greater amount of blood flow.
They originate at the common carotid arteries, enter the cranium through the base
of the skull, and pass through the cavernous sinus. After entering the skull, these
arteries divide into the anterior and middle cerebral arteries (Fig. 15.21). The
vertebral arteries originate at the subclavian arteries and pass through the
transverse foramina of the cervical vertebrae, entering the cranium through the
foramen magnum. They join at the junction of the pons and medulla oblongata to
form the basilar artery. The basilar artery divides at the level of the midbrain to
form paired posterior cerebral arteries (459). When one of the routes is obstructed,
the circle of Willis is an alternate route.
What is the gate control theory of pain? - CORRECT ANSWER- Gate control
theory (GCT) integrates and builds upon features of the other theories to explain
the complex multidimensional aspects of pain perception and pain modulation.
Pain transmission is modulated by a balance of impulses conducted to the spinal
cord where cells in the substantia gelatinosa function as a "gate." The spinal gate
regulates pain transmission to higher centers in the CNS. Large myelinated A-delta
fibers and small unmyelinated C fibers respond to a broad range of painful stimuli
(mechanical, thermal, and chemical). These fibers terminate on interneurons in the
substantia gelatinosa (laminae in the dorsal horn of the spinal cord) and "open" the
spinal gate to transmit the perception of pain. Closure or partial closure of the
spinal gates can occur from nonnociceptive stimulation (i.e., from touch sensors in
the skin) carried on large A-beta fibers decreasing pain perception.
The theories of pain include the specificity theory, pattern theory, gate control
theory, and neuromatrix theory. 4 Specificity theory proposes that pain and touch
are carried on distinct pathways that project to distinct brain centers. Injury
,activates only specific pain receptors and fibers that project to the brain. Intensity
of pain is directly related to the amount of associated tissue injury (i.e., pricking
one's finger with a needle would cause minimal pain, whereas cutting one's hand
with a knife would produce more pain). The theory is useful when applied to
specific injuries and the acute pain associated with them. It does not account for
chronic pain or cognitive and emotional elements that contribute to more complex
types of pain. 5
Know the type of nerve fibers that transmit pain impulses. Page 470 - CORRECT
ANSWER- Transduction begins when nociceptors are activated by a painful
stimulus causing ion channels to open, creating electrical impulses that travel
through axons or two primary types. Pain impulses are conducted along the A-delta
and C fibers of nociceptors.
A-delta fibers: larger myelinated fibers that rapidly transmit sharp, well-localized
"fast" sensations (intense heat or pinprick) "reflex"
· stimulated by mechanoreceptors and mechanothermal nociceptors
· Responsible for causing reflex withdrawal of the body from the painful stimulus
C Fibers: most numerous, smaller, unmyelinated, slowly transmit dull, aching,
burning sensations that are poorly localize and constant
· Stimulated by mechanical, thermal, and chemical nociceptors
A-beta fibers: NOT responsible to transmit pain, but play a role in pain
modulation. Large, myelinated fibers that transmit touch & vibration (p475)
Where in the CNS does pain perception occur? - CORRECT ANSWER- Pain
perception occurs primarily in the reticular and limbic systems and the cerebral
cortex (p476)
It is the conscious awareness of pain; requires the interaction of three systems:
1. Sensory-discriminative system
Mediated by: the somatosensory cortex
Responsibility: identifying the presence, character, location and intensity of pain
2. Affective-motivational system
Mediated by: reticular formation, limbic system, and brainstem with projections to
the prefrontal cortex
Responsibility: individual conditioned avoidance behaviors and emotional
responses to pain
3. Cognitive-evaluative system
Mediated by: cerebral cortex
Responsibility: overlies individual's learned behavior concerning the experience of
pain and can modulate perception of pain
, Know different clinical descriptions of pain (acute, chronic, neuropathic); pain
threshold/tolerance - CORRECT ANSWER- 1. Neurophysiologic Pain
2. Neurogenic Pain
3. Temporal Pain (time related, duration)
4. Pain Location
5. Etiologic Pain
(p480)
signal to the person of a harmful stimulus
· Normal & protective; lasts only seconds to days (up to 3 months)
· Begins suddenly and is relieved after stimulus is removed.
· Clinical signs are related to ANS: ↑HR, HTN, diaphoresis, dilated pupils (476)
(481)
Pain threshold & tolerance are subjective phenomena influence an individual's
perception of pain. Can be influenced by gender, culture, expectations, role
behaviors, physical/mental health, age, fatigue, anger, boredom, apprehension, and
sleep deprivation (Page 471)
Pain threshold: lowest intensity of pain a person can recognize. Different areas of
the body have different thresholds
Pain tolerance is the greatest intensity of pain that a person can endure (p476)
Know endogenous opioids - CORRECT ANSWER- A family of morphine-like
neuropeptides that inhibit transmission of pain impulses in the periphery, spinal
cord, and brain by binding with specific opioid receptors (mu, kappa, delta). They
inhibit ion channels, preventing the release of excitatory neurotransmitters, such as
substance P and glutamate, in the dorsal horn (p478)
In the midbrain, they influence descending inhibitory pathways
· In peripheral inflamed tissue, opioids are produced and released from leukocytes
to activate opioid receptors on sensory nerve terminals. They cannot cross the
blood-brain barrier - this means they do not cause CNS side effects like
drowsiness, ↓respirations, or addiction
· Found in almost all tissues in the body. In addition to analgesia, endogenous
opioids are involved in a variety of other functions in the body including
modulating stress/anxiety, feeding behavior, cough suppression,
immune/inflammatory responses, and alcohol intak
Dynorphins for substance abuse and kappa receptors. (p479)
What are the two type of fibers that transmit the nerve action potentials generated
by excitation of any of the nociceptors - CORRECT ANSWER- Nociceptors =
free nerve endings in the peripheral nervous system that responds to chemical,
AND WELL DETAILED ANSWERS GRADED A+| LATEST EXAM
Review the anatomy of the brain. Which portion is responsible for keeping you
awake, controlling thought, speech, emotions and behavior, maintaining balance
and posture? - CORRECT ANSWER- The reticular formation is a large network
of diffuse nuclei that connect the brainstem to the cortex and control vital reflexes.
It is essential for maintaining wakefulness and is referred to as the reticular
activating system. Some nuclei within the reticular formation support specific
motor movements, such as balance and posture (p448). The cerebellum is
responsible for maintaining balance and posture (p452). The prefrontal area is
responsible for the elaboration of thought (pg 449). The Broca speech area is on
the inferior frontal gyrus (Brodmann 44, 45). It is usually on the left hemisphere
and is responsible for motor aspects of speech. Broca Area in the inferior frontal
lobe (Brodmann areas 44, 45) is an important center for speech and language
processing. This area, rostral to the inferior edge of the premotor area (Brodmann
area 6). Injury to this area results in difficulty forming or inability to for words
(expressive aphasia or dysphasia). Wernicke (posterior Brodmann 22) and adjacent
portions of the parietal lobe are a sensory speech area, responsible for reception
and interpretation of speech (aphasia/dysphasia). Insula (insular lobe) between
hemispheres temporal and frontal lobes, processes emotional information (pg 450).
The basal ganglia nuclei are important for emotional functions (pg 451). Cerebrum
> forebrain/hindbrain
Broca's area = difficulty writing and finding words, See chart 17.10 (p523)
Know the function of the arachnoid villi. - CORRECT ANSWER- The arachnoid
villi protrude from the arachnoid space, through the dura mater, and lie within the
blood flow of the venous sinuses. The villi function as one-way valves directing
CSF outflow into the blood but preventing blood flow into the subarachnoid space.
Thus CSF is formed from the blood and, after circulating throughout the CNS, it
returns to the blood. Absorbs CSF (pg 459)
Where is the primary defect in Parkinson's disease and Huntington's? -
CORRECT ANSWER- Extrapyramidal system; controls motor system
(involuntary movement) (pg 451). Substantia nigra (of the midbrain) synthesizes
dopamine. The dysfunction of dopamine neurons is associated with PD and
Huntington's
What is the function of the CSF? Where is it produced? Where is it absorbed? -
CORRECT ANSWER- Cerebrospinal fluid (CSF) is a clear, colorless fluid
,similar to blood plasma and interstitial fluid. The intracranial and spinal cord
structures float in CSF and are thereby partially protected from jolts and blows.
The buoyant properties of the CSF also prevent the brain from tugging on
meninges, nerve roots, and blood vessels. Appx 600mL is produced daily (457).
Ependymal cells in the choroid plexuses are the structures that produce CSF; they
arise from the pia mater. The arachnoid villi reabsorb the CSF (p458)
Review blood flow to the brain. - CORRECT ANSWER- The brain receives
approximately 20% of the cardiac output, or 800 to 1000 mL of blood flow per
minute. Autoregulated to maintain a stable flow during fluctuating perfusion
pressures. Carbon dioxide serves as a primary regulator for blood flow within the
CNS. It is a potent vasodilator in the CNS, and its effects ensure an adequate blood
supply. The brain derives its arterial supply from the internal carotid arteries
(anterior circulation) and the vertebral arteries (posterior circulation) (Fig. 15.20).
The internal carotid arteries supply a proportionately greater amount of blood flow.
They originate at the common carotid arteries, enter the cranium through the base
of the skull, and pass through the cavernous sinus. After entering the skull, these
arteries divide into the anterior and middle cerebral arteries (Fig. 15.21). The
vertebral arteries originate at the subclavian arteries and pass through the
transverse foramina of the cervical vertebrae, entering the cranium through the
foramen magnum. They join at the junction of the pons and medulla oblongata to
form the basilar artery. The basilar artery divides at the level of the midbrain to
form paired posterior cerebral arteries (459). When one of the routes is obstructed,
the circle of Willis is an alternate route.
What is the gate control theory of pain? - CORRECT ANSWER- Gate control
theory (GCT) integrates and builds upon features of the other theories to explain
the complex multidimensional aspects of pain perception and pain modulation.
Pain transmission is modulated by a balance of impulses conducted to the spinal
cord where cells in the substantia gelatinosa function as a "gate." The spinal gate
regulates pain transmission to higher centers in the CNS. Large myelinated A-delta
fibers and small unmyelinated C fibers respond to a broad range of painful stimuli
(mechanical, thermal, and chemical). These fibers terminate on interneurons in the
substantia gelatinosa (laminae in the dorsal horn of the spinal cord) and "open" the
spinal gate to transmit the perception of pain. Closure or partial closure of the
spinal gates can occur from nonnociceptive stimulation (i.e., from touch sensors in
the skin) carried on large A-beta fibers decreasing pain perception.
The theories of pain include the specificity theory, pattern theory, gate control
theory, and neuromatrix theory. 4 Specificity theory proposes that pain and touch
are carried on distinct pathways that project to distinct brain centers. Injury
,activates only specific pain receptors and fibers that project to the brain. Intensity
of pain is directly related to the amount of associated tissue injury (i.e., pricking
one's finger with a needle would cause minimal pain, whereas cutting one's hand
with a knife would produce more pain). The theory is useful when applied to
specific injuries and the acute pain associated with them. It does not account for
chronic pain or cognitive and emotional elements that contribute to more complex
types of pain. 5
Know the type of nerve fibers that transmit pain impulses. Page 470 - CORRECT
ANSWER- Transduction begins when nociceptors are activated by a painful
stimulus causing ion channels to open, creating electrical impulses that travel
through axons or two primary types. Pain impulses are conducted along the A-delta
and C fibers of nociceptors.
A-delta fibers: larger myelinated fibers that rapidly transmit sharp, well-localized
"fast" sensations (intense heat or pinprick) "reflex"
· stimulated by mechanoreceptors and mechanothermal nociceptors
· Responsible for causing reflex withdrawal of the body from the painful stimulus
C Fibers: most numerous, smaller, unmyelinated, slowly transmit dull, aching,
burning sensations that are poorly localize and constant
· Stimulated by mechanical, thermal, and chemical nociceptors
A-beta fibers: NOT responsible to transmit pain, but play a role in pain
modulation. Large, myelinated fibers that transmit touch & vibration (p475)
Where in the CNS does pain perception occur? - CORRECT ANSWER- Pain
perception occurs primarily in the reticular and limbic systems and the cerebral
cortex (p476)
It is the conscious awareness of pain; requires the interaction of three systems:
1. Sensory-discriminative system
Mediated by: the somatosensory cortex
Responsibility: identifying the presence, character, location and intensity of pain
2. Affective-motivational system
Mediated by: reticular formation, limbic system, and brainstem with projections to
the prefrontal cortex
Responsibility: individual conditioned avoidance behaviors and emotional
responses to pain
3. Cognitive-evaluative system
Mediated by: cerebral cortex
Responsibility: overlies individual's learned behavior concerning the experience of
pain and can modulate perception of pain
, Know different clinical descriptions of pain (acute, chronic, neuropathic); pain
threshold/tolerance - CORRECT ANSWER- 1. Neurophysiologic Pain
2. Neurogenic Pain
3. Temporal Pain (time related, duration)
4. Pain Location
5. Etiologic Pain
(p480)
signal to the person of a harmful stimulus
· Normal & protective; lasts only seconds to days (up to 3 months)
· Begins suddenly and is relieved after stimulus is removed.
· Clinical signs are related to ANS: ↑HR, HTN, diaphoresis, dilated pupils (476)
(481)
Pain threshold & tolerance are subjective phenomena influence an individual's
perception of pain. Can be influenced by gender, culture, expectations, role
behaviors, physical/mental health, age, fatigue, anger, boredom, apprehension, and
sleep deprivation (Page 471)
Pain threshold: lowest intensity of pain a person can recognize. Different areas of
the body have different thresholds
Pain tolerance is the greatest intensity of pain that a person can endure (p476)
Know endogenous opioids - CORRECT ANSWER- A family of morphine-like
neuropeptides that inhibit transmission of pain impulses in the periphery, spinal
cord, and brain by binding with specific opioid receptors (mu, kappa, delta). They
inhibit ion channels, preventing the release of excitatory neurotransmitters, such as
substance P and glutamate, in the dorsal horn (p478)
In the midbrain, they influence descending inhibitory pathways
· In peripheral inflamed tissue, opioids are produced and released from leukocytes
to activate opioid receptors on sensory nerve terminals. They cannot cross the
blood-brain barrier - this means they do not cause CNS side effects like
drowsiness, ↓respirations, or addiction
· Found in almost all tissues in the body. In addition to analgesia, endogenous
opioids are involved in a variety of other functions in the body including
modulating stress/anxiety, feeding behavior, cough suppression,
immune/inflammatory responses, and alcohol intak
Dynorphins for substance abuse and kappa receptors. (p479)
What are the two type of fibers that transmit the nerve action potentials generated
by excitation of any of the nociceptors - CORRECT ANSWER- Nociceptors =
free nerve endings in the peripheral nervous system that responds to chemical,
