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Self Assessment Chapter 12
part 2
• ___________– important functional brain system, includes limbic
lobe (region of medial cerebrum), hippocampus, amygdala, and
pathways; connect each of these regions of gray matter with rest of
brain (Figure 12.9)
• Found only within mammalian brains
• Involved in memory, learning, emotion, and behavior
• When you are nervous and have “butterflies in your stomach” or are scared
and have a racing heart, that reaction is partially a product of your limbic
system.
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The Cerebrum-Limbic System
• Limbic system – important functional brain system, includes limbic
lobe (region of medial cerebrum), hippocampus, amygdala, and
pathways; connect each of these regions of gray matter with rest of
brain (Figure 12.9)
• Found only within mammalian brains
• Involved in memory, learning, emotion, and behavior
• When you are nervous and have “butterflies in your stomach” or are scared
and have a racing heart, that reaction is partially a product of your limbic
system.
© 2016 Pearson Education, Inc.
The Cerebrum-Limbic System
• Limbic system (continued):
• ___________and associated structures form a ring on medial side of cerebral
hemisphere; contain two main gyri: cingulate gyrus and parahippocampal
gyrus
• ___________– in temporal lobe; connected to a prominent C-shaped ring of
white matter (fornix) which is its main output tract; involved in memory and
learning
• ___________– anterior to hippocampus; involved in behavior and expression
of emotion, especially fear
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The Cerebrum-Limbic System
• Limbic system (continued):
• Limbic lobe and associated structures form a ring on medial side of cerebral
hemisphere; contain two main gyri: cingulate gyrus and parahippocampal
gyrus
• Hippocampus – in temporal lobe; connected to a prominent C-shaped ring of
white matter (fornix) which is its main output tract; involved in memory and
learning
• Amygdala – anterior to hippocampus; involved in behavior and expression of
emotion, especially fear
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The Diencephalon
Diencephalon – at physical center of brain; composed of four
components, each with its own nuclei that receive specific input and
send output to other brain regions (Figure 12.10):
• ___________
• ___________
• ___________
• ___________
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The Diencephalon
Diencephalon – at physical center of brain; composed of four
components, each with its own nuclei that receive specific input and
send output to other brain regions (Figure 12.10):
• Thalamus
• Hypothalamus
• Epithalamus
• Subthalamus
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The Diencephalon
• ___________– main entry route of sensory data into cerebral cortex
(Figure 12.10a, b)
• Consists of two egg-shaped regions of gray matter; make up about 80% of
diencephalon
• Third ventricle is found between these two regions
• Thalamic nuclei receive afferent fibers from many other regions of nervous
system excluding information about the sense of smell
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The Diencephalon
• Thalamus – main entry route of sensory data into cerebral cortex
(Figure 12.10a, b)
• Consists of two egg-shaped regions of gray matter; make up about 80% of
diencephalon
• Third ventricle is found between these two regions
• Thalamic nuclei receive afferent fibers from many other regions of nervous
system excluding information about the sense of smell
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The Diencephalon
• Thalamus (continued):
• Regulates cortical activity by controlling which input should continue to
cerebral cortex
• Each half of thalamus has three main groups of nuclei separated by thin layers
of white matter
• Specific nuclei function as ___________that receive input, integrate
information, then send information to specific motor or sensory areas in
cerebral cortex
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The Diencephalon
• Thalamus (continued):
• Regulates cortical activity by controlling which input should continue to
cerebral cortex
• Each half of thalamus has three main groups of nuclei separated by thin layers
of white matter
• Specific nuclei function as relay stations that receive input, integrate
information, then send information to specific motor or sensory areas in
cerebral cortex
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The Diencephalon
• ___________– collection of nuclei anterior and inferior to larger
thalamus
• Neurons perform several vital functions critical to survival; include regulation
of autonomic nervous system, sleep/wake cycle, thirst and hunger, and body
temperature
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The Diencephalon
• Hypothalamus – collection of nuclei anterior and inferior to larger
thalamus
• Neurons perform several vital functions critical to survival; include regulation
of autonomic nervous system, sleep/wake cycle, thirst and hunger, and body
temperature
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The Diencephalon
• Hypothalamus (continued):
• Inferior hypothalamus – anatomically and functionally linked to pituitary
gland by an extension called infundibulum; hypothalamic tissue makes up
posterior portion of this endocrine gland
• Hypothalamus secretes a number of different releasing and inhibiting
hormones; affect function of pituitary gland; in turn, pituitary gland secretes
hormones that affect activities of other endocrine glands throughout body
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The Diencephalon
• Hypothalamus (continued):
• Antidiuretic hormone and oxytocin, hypothalamic hormones that do not
affect pituitary gland, have their effect on water balance and stimulation of
uterine contraction during childbirth, respectively
• Input to hypothalamus arrives from many sources including cortex and basal
nuclei
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___________– makes up posterior and inferior portion of brain;
functionally connected with cerebral cortex, basal nuclei, brainstem,
and spinal cord; interactions between these regions together
coordinate movement (Figure 12.11)
• Anatomically, divided into two cerebellar hemispheres connected by
structure called vermis (Figure 12.11a)
• Ridges called folia cover exterior cerebellar surface; separated by shallow
sulci; increases surface area of region
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Cerebellum
Cerebellum – makes up posterior and inferior portion of brain;
functionally connected with cerebral cortex, basal nuclei, brainstem,
and spinal cord; interactions between these regions together
coordinate movement (Figure 12.11)
• Anatomically, divided into two cerebellar hemispheres connected by
structure called vermis (Figure 12.11a)
• Ridges called folia cover exterior cerebellar surface; separated by shallow
sulci; increases surface area of region
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The Brainstem
Figure 12.12a Midsagittal section of
the brain showing the brainstem.
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The Brainstem
• ___________
• Includes following structures:
• Superior and inferior colliculi, protrude from posterior surface of brainstem; two paired
projections that form roof of midbrain (tectum); involved in visual (reflex centers that
control head and eye movements) and auditory functions respectively; project to
thalamus
• Descending tracts – white matter tracts that originate in cerebrum and form
anteriormost portion of midbrain; called crus cerebri
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The Brainstem
• Midbrain (continued):
• Includes following structures:
• Superior and inferior colliculi, protrude from posterior surface of brainstem; two paired
projections that form roof of midbrain (tectum); involved in visual (reflex centers that
control head and eye movements) and auditory functions respectively; project to
thalamus
• Descending tracts – white matter tracts that originate in cerebrum and form
anteriormost portion of midbrain; called crus cerebri
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The Brainstem
• ___________(continued):
• Pontine tegmentum – surrounded by middle cerebellar peduncles
• Pontine nuclei have many roles including: regulation of movement, breathing,
(assists the medulla in maintaining the normal rhythms of breathing) reflexes,
and complex functions associated with sleep and arousal
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The Brainstem
• Pons (continued):
• Pontine tegmentum – surrounded by middle cerebellar peduncles
• Pontine nuclei have many roles including: regulation of movement, breathing,
(assists the medulla in maintaining the normal rhythms of breathing) reflexes,
and complex functions associated with sleep and arousal
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The Brainstem
• Medulla oblongata (continued):
• Right and left corticospinal fibers ___________ (crossover) within pyramids;
motor fibers originating from right side of cerebral cortex descend through
left side of spinal cord and vice versa
• Posterior columns – paired tracts of white matter found on medulla’s
posterior surface; carry sensory information from spinal cord to nucleus
gracilis and nucleus cuneatus
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The Brainstem
• Medulla oblongata (continued):
• Right and left corticospinal fibers decussate (crossover) within pyramids;
motor fibers originating from right side of cerebral cortex descend through
left side of spinal cord and vice versa
• Posterior columns – paired tracts of white matter found on medulla’s
posterior surface; carry sensory information from spinal cord to nucleus
gracilis and nucleus cuneatus
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The Brainstem
• Autonomic Reflex Center Functions of the ___________
• Cardiovascular center – adjusts the force and rate of heart contractions and
changes blood vessel diameter.
• Respiratory Centers – these generate the respiratory rhythm and with pontine
centers control the rate and depth of breathing
• Various other centers – regulate vomiting, hiccuping, swallowing, coughing,
and sneezing.
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The Brainstem
• Autonomic Reflex Center Functions of the Medulla
• Cardiovascular center – adjusts the force and rate of heart contractions and
changes blood vessel diameter.
• Respiratory Centers – these generate the respiratory rhythm and with pontine
centers control the rate and depth of breathing
• Various other centers – regulate vomiting, hiccuping, swallowing, coughing,
and sneezing.
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The Brainstem
• ___________(continued):
• Central nuclei (center of reticular formation) function in sleep, pain
transmission, and mood
• Nuclei surrounding central nuclei serve motor functions for both skeletal
muscles and autonomic nervous system
• Other nuclei are instrumental in homeostasis of breathing and blood pressure
• Lateral nuclei play a role in sensation and in alertness and activity levels of
cerebral cortex
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The Brainstem
• Reticular formation (continued):
• Central nuclei (center of reticular formation) function in sleep, pain
transmission, and mood
• Nuclei surrounding central nuclei serve motor functions for both skeletal
muscles and autonomic nervous system
• Other nuclei are instrumental in homeostasis of breathing and blood pressure
• Lateral nuclei play a role in sensation and in alertness and activity levels of
cerebral cortex
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Brain Protection
Three features within protective shell of skull provide additional shelter
for delicate brain tissue:
• ___________– three layers of membranes that surround brain
• ___________– fluid that bathes brain and fills cavities
• – prevents many substances from entering brain and its cells from
blood
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Brain Protection
Three features within protective shell of skull provide additional shelter
for delicate brain tissue:
• Cranial meninges – three layers of membranes that surround brain
• Cerebrospinal fluid (CSF) – fluid that bathes brain and fills cavities
• Blood-brain barrier – prevents many substances from entering brain
and its cells from blood
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Brain Protection
• Cranial meninges – composed of three protective membrane layers
of mostly dense irregular collagenous tissue
• Structural arrangement from superficial to deep: epidural space,
___________mater, subdural space, ___________mater, subarachnoid space,
and ___________mater (Figure 12.18)
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Brain Protection
• Cranial meninges – composed of three protective membrane layers
of mostly dense irregular collagenous tissue
• Structural arrangement from superficial to deep: epidural space, dura mater,
subdural space, arachnoid mater, subarachnoid space, and pia mater (Figure
12.18)
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The Ventricles and Cerebrospinal Fluid
Figure 12.19 Ventricles of the brain.
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The Ventricles and Cerebrospinal Fluid
• Cerebrospinal fluid (CSF) – clear, colorless liquid similar in
composition to blood plasma; protects brain in following ways:
• Cushions brain and maintains a constant temperature within cranial cavity
• Removes wastes and increases buoyancy of brain; keeps brain from collapsing
under its own weight
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The Ventricles and Cerebrospinal Fluid
• ___________– where majority of CSF is manufactured; found in each
of four ventricles where blood vessels come into direct contact with
ependymal cells (also produce some CSF themselves)
• Fenestrated capillaries have gaps between endothelial cells; allow fluids and
electrolytes to exit from blood plasma to enter extracellular fluid (ECF)
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The Ventricles and Cerebrospinal Fluid
• Choroid plexuses – where majority of CSF is manufactured; found in
each of four ventricles where blood vessels come into direct contact
with ependymal cells (also produce some CSF themselves)
• Fenestrated capillaries have gaps between endothelial cells; allow fluids and
electrolytes to exit from blood plasma to enter extracellular fluid (ECF)
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The Ventricles and Cerebrospinal Fluid
• Pathway for formation, circulation, and reabsorption of CSF (Figure 12.20):
• Fluid and electrolytes leak out of capillaries of choroid plexuses into ECF of
ventricles
• Taken up into ependymal cells; then secreted into ventricles as CSF
• Circulated through and around brain and spinal cord in subarachnoid space;
assisted by movement of ependymal cell cilia
• Some CSF is reabsorbed into venous blood in dural sinuses via arachnoid
granulations
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The Blood-Brain Barrier
___________– protective safeguard that separates CSF and brain ECF
from chemicals and disease-causing organisms sometimes found in
blood plasma (Figure 12.21)
• Consists mainly of simple squamous epithelial cells (endothelial cells) of
blood capillaries, their basal laminae, and astrocytes
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The Blood-Brain Barrier
Blood-brain barrier – protective safeguard that separates CSF and brain
ECF from chemicals and disease-causing organisms sometimes found in
blood plasma (Figure 12.21)
• Consists mainly of simple squamous epithelial cells (endothelial cells) of
blood capillaries, their basal laminae, and astrocytes
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The Blood-Brain Barrier
Figure 12.21 The blood-brain barrier.
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• ___________– composed primarily of nervous tissue; responsible for
both relaying and processing information; less anatomically complex
than brain but still vitally important to normal nervous system
function; two primary roles:
• Serves as a relay station and as an intermediate point between body and
brain; only means by which brain can interact with body below head and neck
• Processing station for some less complex activities such as spinal reflexes; do
not require higher level processing
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The Spinal Cord
• Spinal cord – composed primarily of nervous tissue; responsible for
both relaying and processing information; less anatomically complex
than brain but still vitally important to normal nervous system
function; two primary roles:
• Serves as a relay station and as an intermediate point between body and
brain; only means by which brain can interact with body below head and neck
• Processing station for some less complex activities such as spinal reflexes; do
not require higher level processing
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Internal Spinal Cord Anatomy
Butterfly-shaped spinal gray matter is surrounded by tracts of white
matter; following features are seen on cross section of spinal cord
(Figures 12.24, 12.25):
• ___________– filled with CSF; seen in center of spinal cord; surrounded by
two thin strips of gray matter (gray commissure); connects each “butterfly”
wing
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Internal Spinal Cord Anatomy
Butterfly-shaped spinal gray matter is surrounded by tracts of white
matter; following features are seen on cross section of spinal cord
(Figures 12.24, 12.25):
• Central canal – filled with CSF; seen in center of spinal cord; surrounded by
two thin strips of gray matter (gray commissure); connects each “butterfly”
wing
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Internal Spinal Cord Anatomy
• Spinal gray matter makes up three distinct regions found within spinal
cord; houses neurons with specific functions and includes (Figure
12.24):
• ___________makes up anterior wing of gray matter and gives rise to anterior
motor nerve roots; neuron cell bodies found in this region are involved in
somatic motor functions (skeletal muscle contraction)
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Internal Spinal Cord Anatomy
• Spinal gray matter makes up three distinct regions found within spinal
cord; houses neurons with specific functions and includes (Figure
12.24):
• Anterior horn (ventral horn) makes up anterior wing of gray matter and gives
rise to anterior motor nerve roots; neuron cell bodies found in this region are
involved in somatic motor functions (skeletal muscle contraction)
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Internal Spinal Cord Anatomy
• Spinal gray matter (continued):
• ___________(or dorsal horn) makes up posterior wing of gray matter and
gives rise to posterior sensory nerve roots; neuron cell bodies found in this
region are involved in processing incoming somatic and visceral sensory
information
• ___________found only in spinal cord between first thoracic vertebra and
lumbar region; contains cell bodies of neurons involved in control of viscera
via autonomic nervous system
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Internal Spinal Cord Anatomy
• Spinal gray matter (continued):
• Posterior horn (or dorsal horn) makes up posterior wing of gray matter and
gives rise to posterior sensory nerve roots; neuron cell bodies found in this
region are involved in processing incoming somatic and visceral sensory
information
• Lateral horn, found only in spinal cord between first thoracic vertebra and
lumbar region; contains cell bodies of neurons involved in control of viscera
via autonomic nervous system
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Internal Spinal Cord Anatomy
Figure 12.24 Overview of internal spinal
cord structure and function.
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Sensory Stimuli
• Sensory stimuli (continued):
• When CNS has received all different sensory inputs, it integrates them into a
single perception (a conscious awareness of sensation)
• Sensations can be grouped into two basic types:
• Special senses – detected by special sense organs and include vision, hearing,
equilibrium, smell, and taste
• General senses – detected by sensory neurons in skin, muscles, or walls of organs; can
be further subdivided into general somatic senses that involve skin, muscles, and joints
and general visceral senses that involve internal organs
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General Somatic Senses
• Basic pathway consists of following:
• ___________detects initial stimulus in PNS; axon of this neuron then
synapses on a second-order neuron
• ___________– interneuron located in posterior horn of spinal cord or in
brainstem; relays stimulus to a third-order neuron
• ___________– an interneuron found in thalamus; delivers impulse to cerebral
cortex
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General Somatic Senses
• Basic pathway consists of following:
• First-order neuron detects initial stimulus in PNS; axon of this neuron then
synapses on a second-order neuron
• Second-order neuron – interneuron located in posterior horn of spinal cord
or in brainstem; relays stimulus to a third-order neuron
• Third-order neuron – an interneuron found in thalamus; delivers impulse to
cerebral cortex
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General Somatic Senses
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General Somatic Senses
Figure 12.26 Ascending (sensory) pathways: the posterior column/medial lemniscal
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systems in the right and left sides of© the
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General Somatic Senses
Figure 12.27 Ascending (sensory) pathways: the right and left spinothalamic tracts (part of
the anterolateral system).
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General Somatic Senses
• Role of Cerebral Cortex in Sensation, S1 and Somatotopy:
• Thalamus relays most incoming information to ___________cortex (____) in
postcentral gyrus
• Each part of body is represented by a specific region of S1, a type of
organization called ___________ (Figure 12.28)
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General Somatic Senses
• Role of Cerebral Cortex in Sensation, S1 and Somatotopy:
• Thalamus relays most incoming information to primary somatosensory
cortex (S1) in postcentral gyrus
• Each part of body is represented by a specific region of S1, a type of
organization called somatotopy (Figure 12.28)
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General Somatic Senses
Figure 12.28 Representations of the
primary somatosensory cortex.
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General Somatic Senses
• Role of the Cerebral Cortex in Sensation – Processing of Pain Stimuli:
perception of pain stimuli is called nociception
• Thalamus relays pain stimuli to several brain regions including S1 and S2
where sensory discrimination (localization, intensity, and quality) is perceived
and analyzed
• Also sent to basal nuclei, regions of limbic system, hypothalamus, and
prefrontal cortex, where emotional and behavioral aspects of pain are
processed
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Voluntary Movement
1.
2.
3.
Upper motor neurons with cell bodies in motor area
of cerebral cortex (most) or brainstem (some) – axons
descend through cerebral white matter to brainstem
and spinal cord; synapse with local interneurons
Local interneurons – pass messages from upper motor
neurons to neighboring lower motor neurons
Cell bodies of lower motor neurons reside in anterior
horn of spinal gray matter; axons (components of
PNS) exit CNS to innervate skeletal muscles
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Motor Pathways from Brain through Spinal
Cord
Figure 12.29 Descending (motor) pathways:
the right and left lateral corticospinal tracts.
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Role of Brain in Voluntary Movement
Even simple movements require simultaneous firing of countless
neurons as part of a selected group of actions called a ___________
Execution of any motor program requires firing of neurons in motor
association areas, firing of upper motor neurons, and input from basal
nuclei, cerebellum, spinal cord, and multimodal association areas (prefrontal
cortex and various sensory areas)
• Firing of lower motor neurons in PNS is necessary to complete task
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Role of Brain in Voluntary Movement
Even simple movements require simultaneous firing of countless
neurons as part of a selected group of actions called a motor program
• Execution of any motor program requires firing of neurons in motor
association areas, firing of upper motor neurons, and input from basal
nuclei, cerebellum, spinal cord, and multimodal association areas
(prefrontal cortex and various sensory areas)
• Firing of lower motor neurons in PNS is necessary to complete task
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Role of Brain in Voluntary Movement
• Role of Basal Nuclei (continued):
• Damage to any component of basal nuclei system results in a
___________disorder; two main forms:
• Inability to initiate voluntary movement, making simple activities such as walking or
talking difficult
• Inability to inhibit inappropriate, involuntary movements; some of which are mild (throat
clearing or blinking); others may be severe enough to cause disability
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Role of Brain in Voluntary Movement
• Role of Basal Nuclei (continued):
• Damage to any component of basal nuclei system results in a movement
disorder; two main forms:
• Inability to initiate voluntary movement, making simple activities such as walking or
talking difficult
• Inability to inhibit inappropriate, involuntary movements; some of which are mild (throat
clearing or blinking); others may be severe enough to cause disability
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Role of Brain in Voluntary Movement
Figure 12.31 Role of the basal nuclei
in voluntary movement.
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Role of Brain in Voluntary Movement
• Role of the Cerebellum (continued):
• Cerebellum receives input from three sources simultaneously:
• motor areas of cerebral cortex via upper motor neurons
• vestibular nuclei of pons
• ascending sensory tracts from spinal cord
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Role of Brain in Voluntary Movement
• Like basal nuclei, cerebellum affects movement by modifying activity
of upper motor neurons; cerebellum does not have direct connections
with lower motor neurons
• Damage to cerebellum makes fluid, well-coordinated movements
nearly impossible; movements become jerky and inaccurate; called
___________
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Role of Brain in Voluntary Movement
• Like basal nuclei, cerebellum affects movement by modifying activity
of upper motor neurons; cerebellum does not have direct connections
with lower motor neurons
• Damage to cerebellum makes fluid, well-coordinated movements
nearly impossible; movements become jerky and inaccurate; called
cerebellar ataxia
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Role of Brain in Voluntary Movement
Figure 12.32 Role of the cerebellum
in voluntary movement.
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The Big Picture of CNS Control of Voluntary
Movement
Figure 12.33 The Big Picture of CNS© Control
of Voluntary Movement.
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Role of CNS in Maintenance of Homeostasis
• Two structures of CNS are concerned directly with maintenance of
homeostasis:
• ___________– controls functions of many internal organs as well as aspects
of behavior
• ___________– closely associated (anatomically and functionally) with
pituitary gland; reflects close relationship between these vital systems
• Reticular formation and hypothalamus have many interconnections; enable
them to coordinate many homeostatic functions
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Role of CNS in Maintenance of Homeostasis
• Two structures of CNS are concerned directly with maintenance of
homeostasis:
• Reticular formation – controls functions of many internal organs as well as
aspects of behavior
• Hypothalamus – closely associated (anatomically and functionally) with
pituitary gland; reflects close relationship between these vital systems
• Reticular formation and hypothalamus have many interconnections; enable
them to coordinate many homeostatic functions
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Homeostasis of Vital Functions
• Maintenance of vital functions (heart pumping, blood pressure, and
digestion) is largely controlled by ___________,regulates function of
body’s viscera
• Although _____is a component of PNS it is controlled by components
of CNS, mainly hypothalamus
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Homeostasis of Vital Functions
• Maintenance of vital functions (heart pumping, blood pressure, and
digestion) is largely controlled by autonomic nervous system (ANS);
regulates function of body’s viscera
• Although ANS is a component of PNS it is controlled by components
of CNS, mainly hypothalamus
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Homeostasis of Vital Functions
• Although ANS is a component of PNS it is controlled by components
of CNS, mainly hypothalamus (continued):
• Hypothalamus receives sensory input from viscera, components of the limbic
system, and the cerebral cortex
• Allows hypothalamus to respond to both normal physiological changes and
emotional changes and to adjust ANS output to maintain homeostasis
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Homeostasis of Vital Functions
• Hypothalamus maintains homeostasis largely by relaying instructions
to nuclei in reticular formation of medulla; include following centers:
• Neurons of vasopressor center – located in anterolateral medulla; when
stimulated by hypothalamus, center increases rate and force of cardiac
contractions and causes blood vessels to narrow; increases blood pressure
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Homeostasis of Vital Functions
• Hypothalamus maintains homeostasis largely by relaying instructions
to nuclei in reticular formation of medulla; include following centers
(continued):
• Vasodepressor center – located inferior and medial to vasopressor center;
decreases rate and force of heart contractions and opens blood vessels; all
three effects decrease blood pressure
• Other centers: many nuclei in reticular formation participate in regulation of
digestive processes and control of urination
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Homeostasis of Vital Functions
• Respiration is one of few vital functions not under ANS control
• Rate and depth of breathing are regulated by group of neurons in anterior
medullary reticular formation
• Several factors influence neuron firing rates: input from cerebral cortex, limbic
system, hypothalamus, certain sensory receptors, and nuclei in pons
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Body Temperature Homeostasis
• Hypothalamus regulates body temperature
• Acts as body’s thermostat; creates a set point for normal body temperature,
about 37 C or 98.6 F
• Input is received from temperature-sensitive neurons located in several places
(skin and areas deeper in body) and from neurons in hypothalamus itself
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Body Temperature Homeostasis
• Hypothalamus regulates body temperature (continued):
• When body temperature increases above set point, a negative feedback loop
is initiated whereby certain hypothalamic nuclei induce changes that cool
body
• When body temperature decreases below set point, a different feedback loop
is initiated that conserves heat
• Both are examples of Feedback Loops Core Principle
• Fever ensues when body temperature set point is temporarily set higher than
normal
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Regulation of Feeding
• Hypothalamus also regulates feeding
• Stimulation of certain hypothalamic nuclei induces hunger and feeding
behaviors; indirectly preserves homeostasis of glucose
• Thought to be related to secretion of neurotransmitters called orexins
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Sleep and Wakefulness
• Sleep (continued):
• Circadian Rhythms and Biological “Clock”: Human sleep follows a
___________We spend a period of cycle awake and remainder asleep
• Rhythm is controlled by hypothalamus; causes changes in level of wakefulness in
response to day and night cycles
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Sleep and Wakefulness
• Sleep (continued):
• Circadian Rhythms and Biological “Clock”: Human sleep follows a circadian
rhythm
• We spend a period of cycle awake and remainder asleep
• Rhythm is controlled by hypothalamus; causes changes in level of wakefulness in
response to day and night cycles
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Sleep and Wakefulness
Figure 12.34 The process of falling ©asleep.
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Sleep and Wakefulness
• Brain Waves and Stages of Sleep (continued):
• State IV sleep is deepest stage with characteristic low- frequency, highamplitude delta waves; stages I–IV collectively is known as non-REM sleep or
non-rapid eye movement sleep
• ___________(rapid eye movement) lasts for 10–15 minutes and occurs after
stage IV sleep; known for back and forth eye movements; stage where most
dreaming occurs; REM waves resemble beta waves of wakefulness
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Sleep and Wakefulness
• Brain Waves and Stages of Sleep (continued):
• State IV sleep is deepest stage with characteristic low- frequency, highamplitude delta waves; stages I–IV collectively is known as non-REM sleep or
non-rapid eye movement sleep
• REM sleep (rapid eye movement) lasts for 10–15 minutes and occurs after
stage IV sleep; known for back and forth eye movements; stage where most
dreaming occurs; REM waves resemble beta waves of wakefulness
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Sleep and Wakefulness
Figure 12.35 Stages of wakefulness©and
sleep as shown by EEG patterns.
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States of Altered Consciousness
Mimicking Sleep
• Altered consciousness can indicate serious problems with brain
function; examples include:
• ___________– diminished level of cortical activity; arousable with
strong/painful stimuli; caused by infections, mental illnesses, and brain
conditions (such as brain tumors)
• ___________– unarousable unconsciousness; no purposeful responses to any
stimuli (even pain); underlying defect is damage to reticular activating system
or related component; prohibits normal arousal of cerebral cortex
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States of Altered Consciousness
Mimicking Sleep
• Altered consciousness can indicate serious problems with brain
function; examples include:
• Stupor – diminished level of cortical activity; arousable with strong/painful
stimuli; caused by infections, mental illnesses, and brain conditions (such as
brain tumors)
• Coma – unarousable unconsciousness; no purposeful responses to any stimuli
(even pain); underlying defect is damage to reticular activating system or
related component; prohibits normal arousal of cerebral cortex
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States of Altered Consciousness
Mimicking Sleep
• Altered consciousness can indicate serious problems with brain
function; examples include (continued):
• ___________– some patients move from coma state to condition where they
are awake but unaware because of damage to cerebral cortex; also lack
voluntary movement
• Sleep/wake cycles do occur; brainstem reflexes remain intact, leading to involuntary
movements (head turning and grunt-like vocalizations)
• Can be misinterpreted as meaningful but not mediated by cortex, thus do not imply
conscious awareness
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States of Altered Consciousness
Mimicking Sleep
• Altered consciousness can indicate serious problems with brain
function; examples include (continued):
• Persistent vegetative state – some patients move from coma state to
condition where they are awake but unaware because of damage to cerebral
cortex; also lack voluntary movement
• Sleep/wake cycles do occur; brainstem reflexes remain intact, leading to involuntary
movements (head turning and grunt-like vocalizations)
• Can be misinterpreted as meaningful but not mediated by cortex, thus do not imply
conscious awareness
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States of Altered Consciousness
Mimicking Sleep
• People in altered states of consciousness may occasionally regain
consciousness, depending on cause of state
• ___________– most extreme state of altered consciousness; EEG
shows no activity; brainstem reflexes are absent; cerebral blood flow
and metabolism are reduced to zero; consciousness will not be
regained
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States of Altered Consciousness
Mimicking Sleep
• People in altered states of consciousness may occasionally regain
consciousness, depending on cause of state
• Brain death – most extreme state of altered consciousness; EEG
shows no activity; brainstem reflexes are absent; cerebral blood flow
and metabolism are reduced to zero; consciousness will not be
regained
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Cognition and Language
• Cognition – collective term for diverse group of tasks; performed by
association areas of cerebral cortex
• Cognitive ___________– include processing and responding to complex
external stimuli, recognizing related stimuli, processing internal stimuli, and
planning appropriate responses to stimuli
• Cognitive ___________– responsible for social and moral behavior,
intelligence, thoughts, problem-solving skills, language, and personality
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Cognition and Language
• Cognition – collective term for diverse group of tasks; performed by
association areas of cerebral cortex
• Cognitive functions – include processing and responding to complex external
stimuli, recognizing related stimuli, processing internal stimuli, and planning
appropriate responses to stimuli
• Cognitive processes – responsible for social and moral behavior, intelligence,
thoughts, problem-solving skills, language, and personality
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Cognition and Language
• Localization of Cognitive Function – following areas and their
functions are involved in cognition:
• Parietal association cortex – responsible for spatial awareness and attention;
allows us to focus on distinct aspects of a specific object and recognize
position of object in space
• Temporal association cortex – primarily responsible for recognizing stimuli,
especially complex stimuli such as faces
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Cognition and Language
• Localization of Cognitive Function (continued):
• Prefrontal cortex – largest and most complex of association cortices
• Responsible for majority of cognitive functions that make up a person’s “character” or
“personality”
• Gathers information from other association cortices and from other sensory and motor
cortices and integrates information to create an awareness of “self”
• Allows for planning and execution of behaviors appropriate for given circumstances
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Cognition and Language
• Cerebral ___________– phenomenon in which many cognitive
functions are unequally represented in right and left hemispheres
• Represents a division of labor between hemispheres to maximize a limited
amount of brain space
• Following functions appear to be lateralized although this is not an absolute
(next slide)
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Cognition and Language
• Cerebral lateralization – phenomenon in which many cognitive
functions are unequally represented in right and left hemispheres
• Represents a division of labor between hemispheres to maximize a limited
amount of brain space
• Following functions appear to be lateralized although this is not an absolute
(next slide)
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Cognition and Language
• Multiple brain regions are required for communication but two multimodal
association areas are critical (Figure 12.36):
• ___________– in frontal lobe; responsible for production of language,
including planning and ordering of words with proper grammar and syntax
• ___________– in temporal lobe; responsible for understanding language and
linking a word with its correct symbolic meaning
• ___________– language deficit; occurs when either of these two critical
areas is damaged
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Cognition and Language
• Multiple brain regions are required for communication but two multimodal
association areas are critical (Figure 12.36):
• Broca’s area – in frontal lobe; responsible for production of language,
including planning and ordering of words with proper grammar and syntax
• Wernicke’s area – in temporal lobe; responsible for understanding language
and linking a word with its correct symbolic meaning
• Aphasia – language deficit; occurs when either of these two critical areas is
damaged
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Learning and Memory
• Two basic types of memory: ___________ (fact) memory – defined as
memory of things that are readily available to consciousness; could in
principle be expressed aloud (hence term “declarative”), and
___________memory (procedural or skills memory); includes skills
and associations that are largely unconscious
• Declarative examples – phone number, a quote, or pathway of corticospinal
tracts
• Nondeclarative examples – how to enter phone number on a phone, how to
move your mouth to speak, and how to read this chapter
© 2016 Pearson Education, Inc.
Learning and Memory
• Two basic types of memory: declarative (fact) memory – defined as
memory of things that are readily available to consciousness; could in
principle be expressed aloud (hence term “declarative”), and
nondeclarative memory (procedural or skills memory); includes skills
and associations that are largely unconscious
• Declarative examples – phone number, a quote, or pathway of corticospinal
tracts
• Nondeclarative examples – how to enter phone number on a phone, how to
move your mouth to speak, and how to read this chapter
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Learning and Memory
• Declarative and nondeclarative memory can be classified by length of
time in which they are stored:
• ___________– stored only for a few seconds; is critical for carrying out normal
conversation, reading, and daily tasks
• ___________ (working) memory – stored for several minutes; allows you to
remember and manipulate information with a general behavioral goal in mind
• ___________– a more permanent form of storage for days, weeks, or even a
lifetime
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Learning and Memory
• Declarative and nondeclarative memory can be classified by length of
time in which they are stored:
• Immediate memory – stored only for a few seconds; is critical for carrying out
normal conversation, reading, and daily tasks
• Short-term (working) memory – stored for several minutes; allows you to
remember and manipulate information with a general behavioral goal in mind
• Long-term memory – a more permanent form of storage for days, weeks, or
even a lifetime
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Learning and Memory
• Process of converting immediate or working memory into long-term
memory involves a process called ___________ (Figure 12.37)
• Formation and storage of declarative memory appears to require
hippocampus (component of limbic system); immediate and shortterm memories are likely stored in this region
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Learning and Memory
• Process of converting immediate or working memory into long-term
memory involves a process called consolidation (Figure 12.37)
• Formation and storage of declarative memory appears to require
hippocampus (component of limbic system); immediate and shortterm memories are likely stored in this region
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Learning and Memory
• ___________) – mechanism by which hippocampal neurons encode
long-term declarative memories, seems to involve an increase in
synaptic activity between associated neurons; example of Cell-Cell
Communication Core Principle
• Although hippocampus is required to form new declarative memories, longterm memories are not stored in this region; stored in cerebral cortex that
correlates with their functions
• Retrieval of memories seems to be mediated by pathways involving
hippocampus and prefrontal cortex
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Learning and Memory
• Long-term potentiation (LTP) – mechanism by which hippocampal
neurons encode long-term declarative memories, seems to involve an
increase in synaptic activity between associated neurons; example of
Cell-Cell Communication Core Principle
• Although hippocampus is required to form new declarative memories, longterm memories are not stored in this region; stored in cerebral cortex that
correlates with their functions
• Retrieval of memories seems to be mediated by pathways involving
hippocampus and prefrontal cortex
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Learning and Memory
Figure 12.37 Pathways for consolidation
of memories.
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Learning and Memory
• Emotion – complex combination of three separate phenomena:
• Visceral motor responses – blushing or heart racing; mediated by
hypothalamus
• Somatic motor responses – smiling, laughing, frowning, and crying; mediated
by hypothalamus and limbic cortex through reticular formation
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Learning and Memory
• Emotion (continued):
• “Feelings” – highly subjective; most complex; integrated with sensory and/or
cognitive stimuli
• Feeling sad when remembering a lost pet or feeling tense when watching a suspenseful
movie
• Amygdala receives input from brainstem, thalamus, cerebral cortex, and basal nuclei,
analyzes emotional significance of stimuli; creates associations between different
stimuli; projects to prefrontal cortex
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