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Language AreasLanguage Areas
Located in a large area surrounding the left (or Located in a large area surrounding the left (or language-dominant) lateral sulcuslanguage-dominant) lateral sulcus
Major parts and functions:Major parts and functions: Wernicke’s area –sounding out unfamiliar wordsWernicke’s area –sounding out unfamiliar words Broca’s area – speech preparation and productionBroca’s area – speech preparation and production Lateral prefrontal cortex – language Lateral prefrontal cortex – language
comprehension and word analysiscomprehension and word analysis Lateral and ventral temporal lobe – coordinate Lateral and ventral temporal lobe – coordinate
auditory and visual aspects of languageauditory and visual aspects of language
General (Common) General (Common) Interpretation AreaInterpretation Area
Ill-defined region including parts of the Ill-defined region including parts of the temporal, parietal, and occipital lobestemporal, parietal, and occipital lobes
Found in one hemisphere, usually the leftFound in one hemisphere, usually the left Integrates incoming signals into a single Integrates incoming signals into a single
thoughtthought Involved in processing spatial relationshipsInvolved in processing spatial relationships
Visceral Association AreaVisceral Association Area
Located in the cortex of the insulaLocated in the cortex of the insula Involved in conscious perception of visceral Involved in conscious perception of visceral
sensationssensations
Lateralization of Cortical Lateralization of Cortical FunctionFunction
Lateralization – each hemisphere has abilities Lateralization – each hemisphere has abilities not shared with its partnernot shared with its partner
Cerebral dominance – designates the Cerebral dominance – designates the hemisphere dominant for languagehemisphere dominant for language
Left hemisphere – controls language, math, Left hemisphere – controls language, math, and logicand logic
Right hemisphere – controls visual-spatial Right hemisphere – controls visual-spatial skills, emotion, and artistic skillsskills, emotion, and artistic skills
Cerebral White MatterCerebral White Matter
Consists of deep myelinated fibers and their Consists of deep myelinated fibers and their tractstracts
It is responsible for communication between: It is responsible for communication between: The cerebral cortex and lower CNS center, and The cerebral cortex and lower CNS center, and
areas of the cerebrumareas of the cerebrum
Cerebral White MatterCerebral White Matter
Types include:Types include: Commissures – connect corresponding gray areas Commissures – connect corresponding gray areas
of the two hemispheresof the two hemispheres Association fibers – connect different parts of the Association fibers – connect different parts of the
same hemispheresame hemisphere Projection fibers – enter the hemispheres from Projection fibers – enter the hemispheres from
lower brain or cord centerslower brain or cord centers
Basal NucleiBasal Nuclei
Masses of gray matter found deep within the Masses of gray matter found deep within the cortical white mattercortical white matter
The corpus striatum is composed of three partsThe corpus striatum is composed of three parts Caudate nucleusCaudate nucleus Lentiform nucleus – composed of the putamen and Lentiform nucleus – composed of the putamen and
the globus pallidusthe globus pallidus Fibers of internal capsule running between and Fibers of internal capsule running between and
through caudate and lentiform nucleithrough caudate and lentiform nuclei
Functions of Basal NucleiFunctions of Basal Nuclei
Though somewhat elusive, the following are Though somewhat elusive, the following are thought to be functions of basal nucleithought to be functions of basal nuclei Influence muscular activity Influence muscular activity Regulate attention and cognitionRegulate attention and cognition Regulate intensity of slow or stereotyped Regulate intensity of slow or stereotyped
movementsmovements Inhibit antagonistic and unnecessary movementInhibit antagonistic and unnecessary movement
DiencephalonDiencephalon
Central core of the forebrainCentral core of the forebrain Consists of three paired structures – thalamus, Consists of three paired structures – thalamus,
hypothalamus, and epithalamushypothalamus, and epithalamus Encloses the third ventricleEncloses the third ventricle
ThalamusThalamus
Paired, egg-shaped masses that form the Paired, egg-shaped masses that form the superolateral walls of the third ventriclesuperolateral walls of the third ventricle
Connected at the midline by the intermediate Connected at the midline by the intermediate massmass
Contains four groups of nuclei – anterior, Contains four groups of nuclei – anterior, ventral, dorsal, and posteriorventral, dorsal, and posterior
Nuclei project and receive fibers from the Nuclei project and receive fibers from the cerebral cortexcerebral cortex
Thalamic FunctionThalamic Function
Sensual afferent impulses converge and Sensual afferent impulses converge and synapse in the thalamussynapse in the thalamus
Impulses of similar function are sorted out, Impulses of similar function are sorted out, edited, and relayed as a groupedited, and relayed as a group
All inputs ascending to the cerebral cortex All inputs ascending to the cerebral cortex pass through the thalamuspass through the thalamus
Mediates sensation, motor activities, cortical Mediates sensation, motor activities, cortical arousal, learning, and memoryarousal, learning, and memory
HypothalamusHypothalamus
Located below the thalamus, it caps the brainstem and Located below the thalamus, it caps the brainstem and forms the inferolateral walls of the third ventricleforms the inferolateral walls of the third ventricle
Mammillary bodiesMammillary bodies Small, paired nuclei bulging anteriorly from the Small, paired nuclei bulging anteriorly from the
hypothalamushypothalamus Relay station for olfactory pathwaysRelay station for olfactory pathways
Infundibulum – stalk of the hypothalamus; connects Infundibulum – stalk of the hypothalamus; connects to the pituitary glandto the pituitary gland Main visceral control center of the bodyMain visceral control center of the body
Hypothalamic FunctionHypothalamic Function
Regulates blood pressure, rate and force of Regulates blood pressure, rate and force of heartbeat, digestive tract motility, rate and heartbeat, digestive tract motility, rate and depth of breathing, and many other visceral depth of breathing, and many other visceral activitiesactivities
Perception of pleasure, fear, and ragePerception of pleasure, fear, and rage Maintains normal body temperatureMaintains normal body temperature Regulates feelings of hunger and satiety Regulates feelings of hunger and satiety Regulates sleep and the sleep cycleRegulates sleep and the sleep cycle
Endocrine Functions of the Endocrine Functions of the HypothalamusHypothalamus
Releasing hormones control secretion of Releasing hormones control secretion of hormones by the anterior pituitaryhormones by the anterior pituitary
The supraoptic and paraventricular nuclei The supraoptic and paraventricular nuclei produce ADH and oxytocinproduce ADH and oxytocin
EpithalamusEpithalamus
Most dorsal portion of the diencephalon; forms Most dorsal portion of the diencephalon; forms roof of the third ventricleroof of the third ventricle
Pineal gland – extends from the posterior Pineal gland – extends from the posterior border and secretes melatoninborder and secretes melatonin Melatonin – a hormone involved with sleep Melatonin – a hormone involved with sleep
regulation, sleep-wake cycles, and moodregulation, sleep-wake cycles, and mood Choroid plexus – a structure that secretes Choroid plexus – a structure that secretes
cerebral spinal fluid (CSF)cerebral spinal fluid (CSF)
Brain StemBrain Stem
Consists of three regions – midbrain, pons, and Consists of three regions – midbrain, pons, and medulla oblongatamedulla oblongata
Similar to spinal cord but contains embedded Similar to spinal cord but contains embedded nucleinuclei
Controls automatic behaviors necessary for Controls automatic behaviors necessary for survivalsurvival
Provides the pathway for tracts between higher Provides the pathway for tracts between higher and lower brain centersand lower brain centers
Associated with 10 of the 12 pairs of cranial Associated with 10 of the 12 pairs of cranial nervesnerves
MidbrainMidbrain
Located between the diencephalon and the Located between the diencephalon and the ponspons
Midbrain structures include:Midbrain structures include: Cerebral peduncles – two bulging structures that Cerebral peduncles – two bulging structures that
contain descending pyramidal motor tractscontain descending pyramidal motor tracts Cerebral aqueduct – hollow tube that connects the Cerebral aqueduct – hollow tube that connects the
third and fourth ventriclesthird and fourth ventricles Various nucleiVarious nuclei
Midbrain NucleiMidbrain Nuclei
Nuclei that control cranial nerves III Nuclei that control cranial nerves III (oculomotor) and IV (trochlear)(oculomotor) and IV (trochlear)
Corpora quadrigemina – four domelike Corpora quadrigemina – four domelike protrusions of the dorsal midbrainprotrusions of the dorsal midbrain
Superior colliculi – visual reflex centersSuperior colliculi – visual reflex centers
Midbrain NucleiMidbrain Nuclei
Inferior colliculi – auditory relay centersInferior colliculi – auditory relay centers Substantia nigra – functionally linked to basal Substantia nigra – functionally linked to basal
nucleinuclei Red nucleus – largest nucleus of the reticular Red nucleus – largest nucleus of the reticular
formation; red nuclei are relay nuclei for some formation; red nuclei are relay nuclei for some descending motor pathwaysdescending motor pathways
PonsPons
Bulging brainstem region between the Bulging brainstem region between the midbrain and the medulla oblongatamidbrain and the medulla oblongata
Forms part of the anterior wall of the fourth Forms part of the anterior wall of the fourth ventricleventricle
Fibers of the pons:Fibers of the pons: Connect higher brain centers and the spinal cordConnect higher brain centers and the spinal cord Relay impulses between the motor cortex and the Relay impulses between the motor cortex and the
cerebellumcerebellum
PonsPons
Origin of cranial nerves V (trigeminal), VI Origin of cranial nerves V (trigeminal), VI (abducens), and VII (facial)(abducens), and VII (facial)
Contains nuclei of the reticular formationContains nuclei of the reticular formation
Medulla OblongataMedulla Oblongata
Most inferior part of the brain stemMost inferior part of the brain stem Along with the pons, forms the ventral wall of Along with the pons, forms the ventral wall of
the fourth ventriclethe fourth ventricle Contains a choroid plexus of the fourth ventricleContains a choroid plexus of the fourth ventricle Pyramids – two longitudinal ridges formed by Pyramids – two longitudinal ridges formed by
corticospinal tractscorticospinal tracts Decussation of the pyramids – crossover points Decussation of the pyramids – crossover points
of the corticospinal tractsof the corticospinal tracts
Medulla NucleiMedulla Nuclei
Inferior olivary nuclei – gray matter that relays Inferior olivary nuclei – gray matter that relays sensory informationsensory information
Cranial nerves X, XI, and XII are associated Cranial nerves X, XI, and XII are associated with the medullawith the medulla
Vestibular nuclear complex – synapses that Vestibular nuclear complex – synapses that mediate and maintain equilibriummediate and maintain equilibrium
Ascending sensory tract nuclei, including Ascending sensory tract nuclei, including nucleus cuneatus and nucleus gracilisnucleus cuneatus and nucleus gracilis
Medulla NucleiMedulla Nuclei
Cardiovascular control center – adjusts force Cardiovascular control center – adjusts force and rate of heart contractionand rate of heart contraction
Respiratory centers – control rate and depth of Respiratory centers – control rate and depth of breathingbreathing
Additional centers – regulate vomiting, Additional centers – regulate vomiting, hiccuping, swallowing, coughing, and hiccuping, swallowing, coughing, and sneezingsneezing
The CerebellumThe Cerebellum
Located dorsal to the pons and medullaLocated dorsal to the pons and medulla Protrudes under the occipital lobes of the Protrudes under the occipital lobes of the
cerebrumcerebrum Makes up 11% of the brain’s massMakes up 11% of the brain’s mass Provides precise timing and appropriate Provides precise timing and appropriate
patterns of skeletal muscle contractionpatterns of skeletal muscle contraction Cerebellar activity occurs subconsciouslyCerebellar activity occurs subconsciously
Anatomy of the CerebellumAnatomy of the Cerebellum
Two bilaterally symmetrical hemispheres Two bilaterally symmetrical hemispheres connected medially by the vermisconnected medially by the vermis
Folia – transversely oriented gyriFolia – transversely oriented gyri Each hemisphere has three lobes – anterior, Each hemisphere has three lobes – anterior,
posterior, and flocculonodularposterior, and flocculonodular Neural arrangement – gray matter cortex, Neural arrangement – gray matter cortex,
internal white matter, scattered nucleiinternal white matter, scattered nuclei Arbor vitae – distinctive treelike pattern of the Arbor vitae – distinctive treelike pattern of the
cerebellar white mattercerebellar white matter
Cerebellar PedunclesCerebellar Peduncles
Three paired fiber tracts that connect the Three paired fiber tracts that connect the cerebellum to the brain stemcerebellum to the brain stem
All fibers in the cerebellum are ipsilateralAll fibers in the cerebellum are ipsilateral Superior peduncles connect the cerebellum to Superior peduncles connect the cerebellum to
the midbrainthe midbrain Middle peduncles connect the pons to the Middle peduncles connect the pons to the
cerebellumcerebellum Inferior peduncles connect the medulla to the Inferior peduncles connect the medulla to the
cerebellumcerebellum
Cerebellar ProcessingCerebellar Processing
Cerebellum receives impulses of the intent to Cerebellum receives impulses of the intent to initiate voluntary muscle contractioninitiate voluntary muscle contraction
Proprioceptors and visual signals “inform” the Proprioceptors and visual signals “inform” the cerebellum of the body’s conditioncerebellum of the body’s condition
Cerebellar cortex calculates the best way to Cerebellar cortex calculates the best way to perform a movementperform a movement
A “blueprint” of coordinated movement is sent A “blueprint” of coordinated movement is sent to the cerebral motor cortexto the cerebral motor cortex