Ch 12 Lecture Outline b

8/8/2019 Ch 12 Lecture Outline b

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PowerPoint Lecture Slides

prepared by

Janice Meeking,

Mount Royal College

C H A P T E R

Copyright 2010 Pearson Education, Inc.

12The Central

NervousSystem:Part B


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Multimodal Association Areas

Receive inputs from multiple sensory areas

Send outputs to multiple areas, including the

premotor cortex

Allow us to give meaning to information

received, store it as memory, compare it to

previous experience, and decide on action to

take


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Multimodal Association Areas

Three parts

Anterior association area (prefrontal cortex)

Posterior association area

Limbic association area


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Anterior Association Area (Prefrontal

Cortex)

Most complicated cortical region

Involved with intellect, cognition, recall, and

personality

Contains working memory needed for

judgment, reasoning, persistence, and

conscience

Development depends on feedback from

social environment


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Posterior Association Area

Large region in temporal, parietal, andoccipital lobes

Plays a role in recognizing patterns and faces

and localizing us in space

Involved in understanding written and spoken

language (Wernickes area)


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Limbic Association Area

Part of the limbic system

Provides emotional impact that helps

establish memories


7/44Copyright 2010 Pearson Education, Inc.

Lateralization of Cortical Function Lateralization

Division of labor between hemispheres Cerebral dominance

Designates the hemisphere dominant for language (left hemisphere in 90% ofpeople)

Left hemisphere Controls language, math, and logic

Right hemisphere

Insight, visual-spatial skills, intuition, and artistic skills

Left and right hemispheres communicate via fiber tracts in the cerebral

white matter



Cerebral White Matter Myelinated fibers and their tracts

Responsible for communication Commissures (in corpus callosum)connect gray matter of

the two hemispheres

Association fibersconnect different parts of the same

hemisphere

Projection fibers(corona radiata) connect the hemispheres

with lower brain or spinal cord


9/44Copyright 2010 Pearson Education, Inc. Figure 12.10a

Corona radiata

Projectionfibers

Longitudinal fissure

Gray matter

White matter

Association

fibers

Lateral

ventricle

Fornix

Third

ventricle

Thalamus

Pons

Medulla oblongataDecussation

of pyramids

Commissural

fibers (corpus

callosum)

Internal

capsule

Superior

Basal nuclei Caudate

Putamen

Globus

pallidus

(a)



Basal Nuclei (Ganglia)

Consists of the corpus striatum

Caudate nucleus

Lentiform nucleus (putamen + globus pallidus)

Though somewhat elusive, the following are thought to be

functions of basal nuclei Influence muscular control

Help regulate attention and cognition

Regulate intensity of slow or stereotyped movements

Inhibit antagonistic and unnecessary movements



Fibers of

corona radiata

Corpus

striatum

(a)

Projection fibersrun deep to

lentiform nucleus

Caudate

nucleus Thalamus

Tail of

caudate

nucleus

Lentiformnucleus

Putamen

Globus pallidus

(deep to putamen)


12/44Copyright 2010 Pearson Education, Inc. Figure 12.11b (1 of 2)

Corpus callosumAnterior horn

of lateral ventricleCaudate nucleusPutamen

Lentiform

nucleus

(b)

Globus

pallidus

ThalamusTail of caudate nucleusThird ventricle

Cerebral cortexCerebral white matter

Anterior

Posterior

Inferior horn

of lateral ventricle


13/44Copyright 2010 Pearson Education, Inc. Figure 12.11b (2 of 2)

Corpus callosumAnterior horn

of lateral ventricleCaudate nucleus

Lentiform nucleus

(b)

Thalamus

Third ventricle

Cerebral cortexCerebral white matter

Inferior horn

of lateral ventricle



Diencephalon

Three paired structures

Thalamus

Hypothalamus Epithalamus

Encloses the third ventricle

Pineal gland(part of epithalamus)


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Dorsal nuclei

Medial

Anterior

nucleargroup

Reticular

nucleus

Ventralanterior

Ventrallateral

Ventral

postero-lateral

Lateral

geniculate

body

Medial

geniculate

body

Pulvinar

Lateral

dorsal

Lateral

posterior

(a) The main thalamic nuclei. (The reticular nuclei that cap the

thalamus laterally are depicted as curving translucent structures.)

Ventral nuclei



Hypothalamus

Forms the inferolateral walls of the thirdventricle

Contains many nuclei

Example: mammillary bodies

Paired anterior nuclei

Olfactory relay stations

Infundibulumstalk that connects to thepituitary gland


18/44Copyright 2010 Pearson Education, Inc. Figure 12.13b

Preopticnucleus

SupraopticnucleusSupra-chiasmaticnucleus

Anteriorhypothalamic

nucleus

Dorsomedialnucleus

Paraventricularnucleus

FornixAnteriorcommissure

Posteriorhypothalamicnucleus

Lateral

hypothalamicarea

Ventromedial

nucleus

OpticchiasmaInfundibulum

(stalk of the

pituitary gland)

Pituitary

gland

Mammillary

body

(b) The main hypothalamic nuclei.

Arcuate

nucleus



Hypothalamic Function Autonomic control center for many visceral functions (e.g.,

blood pressure, rate and force of heartbeat, digestive tract

motility) Center for emotional response: Involved in perception of

pleasure, fear, and rage and in biological rhythms and drives

Regulates body temperature, food intake, water balance, and

thirst

Regulates sleep and the sleep cycle

Controls release of hormones by the anterior pituitary

Produces posterior pituitary hormones



Epithalamus

Most dorsal portion of the diencephalon;forms roof of the third ventricle

Pineal glandextends from the posterior

border and secretes melatonin

Melatoninhelps regulate sleep-wake cycles


21/44Copyright 2010 Pearson Education, Inc. Figure 12.12

Corpus callosum

Choroid plexusThalamus(encloses third

ventricle)

Pineal gland(part of epithalamus)

Posterior commissure

Corpora

quadrigeminaCerebral

aqueductArbor vitae (of

cerebellum)

Fourth ventricleChoroid plexusCerebellum

Septum pellucidumInterthalamic

adhesion

(intermediate

mass of

thalamus)Interven-

tricular

foramen

Anterior

commissure

Hypothalamus

Optic chiasma

Pituitary gland

Cerebral hemisphere

Mammillary bodyPons

Medulla oblongata

Spinal cord

Mid-

brain

Fornix



Brain Stem

Three regions

Midbrain

Pons

Medulla oblongata



Brain Stem Similar structure to spinal cord but contains

embedded nuclei Controls automatic behaviors necessary for survival

Contains fiber tracts connecting higher and lower

neural centers

Associated with 10 of the

12 pairs of cranial nerves


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Copyright 2010 Pearson Education, Inc. Figure 12.15a

Optic chiasmaView (a)

Optic nerve (II)

Mammillary body

Oculomotor nerve (III)

Crus cerebri of

cerebral peduncles

(midbrain)

Trigeminal nerve (V)

Abducens nerve (VI)Facial nerve (VII)

Vagus nerve (X)

Accessory nerve (XI)

Hypoglossal nerve (XII)

Ventral root of first

cervical nerve

Trochlear nerve (IV)

PonsMiddle cerebellarpeduncle

Pyramid

Decussation of pyramids

(a) Ventral view

Spinal cord

Vestibulocochlear

nerve (VIII)Glossopharyngeal nerve (IX)

Diencephalon

Thalamus Hypothalamus

Diencephalon

Brainstem

Thalamus

Hypothalamus

Midbrain

Pons

Medulla

oblongata


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Copyright 2010 Pearson Education, Inc. Figure 12.15b

View (b)

Crus cerebri ofcerebral peduncles

(midbrain)

Infundibulum

Pituitary gland

Trigeminal nerve (V)

Abducens nerve (VI)

Facial nerve (VII)

Vagus nerve (X)

Accessory nerve (XI)

Hypoglossal nerve (XII)

Pons

(b) Left lateral view

Glossopharyngeal nerve (IX)

Diencephalon

Brainstem

Thalamus

Hypothalamus

Midbrain

Pons

Medulla

oblongata

Thalamus

Superior colliculus

Inferior colliculus


Superior cerebellar peduncleMiddle cerebellar peduncle

Inferior cerebellar peduncle

Vestibulocochlear nerve (VIII)

Olive


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Copyright 2010 Pearson Education, Inc. Figure 12.15c

View (c)

Diencephalon

Brainstem

Thalamus

Hypothalamus

Midbrain

Pons

Medulla

oblongata

Pineal gland

Diencephalon

Anterior wall of

fourth ventricle

(c) Dorsal view

Thalamus

Dorsal root of

first cervical nerve

Midbrain Superior

colliculus Inferior

colliculus


Superior cerebellar peduncle

Corpora

quadrigemina

of tectum

Medulla oblongata

Inferior cerebellar peduncle Facial nerve (VII) Vestibulocochlear nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Accessory nerve (XI)

Pons

Middle cerebellar peduncle

Dorsal median sulcus

Choroid plexus(fourth ventricle)


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Copyright 2010 Pearson Education, Inc. Figure 12.16a

Dorsal

Cerebral aqueduct

Superior

colliculus

Reticular formation

Crus cerebri of

cerebral peduncle

Ventral

Fibers of

pyramidal tract

Substantianigra

(a) Midbrain

Red

nucleus

Medial

lemniscus

Oculomotornucleus (III)

Periaqueductal gray

matter

Tectum


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Pons

Forms part of the anterior wall of the fourth ventricle

Fibers of the pons

Connect higher brain centers and the spinal cord

Relay impulses between the motor cortex and thecerebellum

Origin of cranial nerves V (trigeminal), VI (abducens),

and VII (facial) Some nuclei of the reticular formation

Nuclei that help maintain normal rhythm of breathing


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Reticular

formation

Trigeminal

nerve (V)

Pontine

nuclei

Fibers of

pyramidal

tract

Middle

cerebellar

peduncle

Trigeminal main

sensory nucleus

Trigeminal

motor nucleus

Superior cerebellar

peduncle

Medial lemniscus

Fourth

ventricle

(b) Pons


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Medulla Oblongata

Joins spinal cord at foramen magnum

Forms part of the ventral wall of the fourthventricle

Contains a choroid plexus of the fourthventricle

Pyramidstwo ventral longitudinal ridges

formed by pyramidal tracts Decussation of the pyramidscrossover of

the corticospinal tracts


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Medulla Oblongata

Inferior olivary nucleirelay sensoryinformation from muscles and joints tocerebellum

Cranial nerves VIII, X, and XII are associatedwith the medulla

Vestibular nuclear complexmediatesresponses that maintain equilibrium

Several nuclei (e.g., nucleus cuneatus andnucleus gracilis) relay sensory information


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Medulla Oblongata

Autonomic reflex centers

Cardiovascular center

Cardiac center adjusts force and rate of heart

contraction

Vasomotor center adjusts blood vessel

diameter for blood pressure regulation


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Medulla Oblongata

Respiratory centers

Generate respiratory rhythm

Control rate and depth of breathing, with

pontine centers


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Medulla Oblongata

Additional centers regulate

Vomiting

Hiccuping

Swallowing

Coughing

Sneezing


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Copyright 2010 Pearson Education, Inc. Figure 12.16c

Choroid

plexus

Fourth ventricle

PyramidMedial lemniscus

Inferior olivary

nucleus

Nucleus

ambiguus

Inferior cerebellarpeduncle Cochlearnuclei (VIII)

Vestibular nuclear

complex (VIII)

Solitary

nucleusDorsal motor nucleusof vagus (X)

Hypoglossal nucleus (XII)

(c) Medulla oblongata

LateralnucleargroupMedial

nucleargroup

Raphe

nucleusReticul a

rformation


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The Cerebellum

11% of brain mass

Dorsal to the pons and medulla

Subconsciously provides precise timing and

appropriate patterns of skeletal muscle

contraction


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Anatomy of the Cerebellum

Two hemispheres connected by vermis

Each hemisphere has three lobes

Anterior, posterior, and flocculonodular

Foliatransversely oriented gyri

Arbor vitaedistinctive treelike pattern of the

cerebellar white matter


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(b)

Medulla

oblongataFlocculonodular

lobe

Choroid

plexus of

fourth

ventricle

Posterior

lobe

Arbor

vitae

Cerebellar cortex

Anterior lobe

Cerebellar

peduncles

Superior Middle Inferior


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Copyright 2010 Pearson Education, Inc. Figure 12.17d

(d)

Anterior

lobe

Posterior

lobe

Vermis(d)


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Cerebellar Peduncles

All fibers in the cerebellum are ipsilateral Three paired fiber tracts connect the

cerebellum to the brain stem

Superior peduncles connect the cerebellum tothe midbrain

Middle peduncles connect the pons to thecerebellum

Inferior peduncles connect the medulla to thecerebellum


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Cerebellar Processing for Motor Activity

Cerebellum receives impulses from the cerebralcortex of the intent to initiate voluntary muscle

contraction

Signals from proprioceptors and visual and

equilibrium pathways continuously inform the

cerebellum of the bodys position and momentum

Cerebellar cortex calculates the best way to

smoothly coordinate a muscle contraction A blueprint of coordinated movement is sent to the

cerebral motor cortex and to brain stem nuclei


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Cognitive Function of the Cerebellum

Recognizes and predicts sequences of eventsduring complex movements

Plays a role in nonmotor functions such as

word association and puzzle solving

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