THE LECTURE ON BRAIN 2013

A SHORT OVERVIEWHAMIADJI

DEVELOPMENT OF THE BRAIN

The Brain (Encephalon) includes:1. The Cerebrum that contains; - The Telencephalon (cortex, white matter and basal nuclei)2. The Diencephalon (dorsal

thalamus, hypothalamus, epithalamus, and subthalamus)

3. The Brainstem (midbrain, pons, and medulla oblongata)

4. The Cerebellum (lobes and Vermis)

THE CENTRAL NERVOUS SYSTEM

5. The Cerebellum (lobes and vermis)

Develops from the roof of the metencephalon

INTRODUCTION

The following will be discussed:1. Cerebral Cortex2. Basal ganglia (nuclei)3. Cerebral white matter

White Matter

Basal Nuclei

Cortex

I. THE LOBES OF THE CEREBRUM

III. THE MAIN CORTICAL FUNCTIONAL AREAS

Wernicke’s area = Br22 + Br39

III. THE MAIN CORTICAL FUNCTIONAL AREAS

• Primary sensory cortex --- postcentral gyrus --- Br. 1, 2, 3• Primary visual cortex --- both sides of calcarine sulcus --- Br. 17• Primary auditory cortex--- transverse gyri of Heschl --- Br. 41, 42• Olfactory cortex--- area of the uncus --- Br. 28• Motor cortex --- precentral gyrus --- Br. 4• Motor speech area (Broca’s area) --- Br. 44, 45• Frontal eyefield --- Br. 6 - 8• Auditory association cortex (Wernicke’s area) --- Br. 22, 39• Integration center --- Br. 5, 7, 40• Visual association cortex --- Br. 18, 19

Note: Lesion to the Wernicke’s area results in Receptive aphasia (alexia) Lesion to the Broca’s area results in Expressive aphasia (agraphia)

IV. THE HOMUNCULI OF PENFIELD

Representation of the body on the cerebral cortex.Motor homunculusSensory homunculus

THE HOMUNCULI OF PENFIELD

LARGE representation of a body part means many neurons are controlling that part (many small motor units) & sensory neurons

Face – many expressions &

sensationsHand – many fine

movements & sensations

V. LEFT AND RIGHT HEMISPHERES

The left hemisphere has been called the dominant or major hemisphere --- verbal and analytical abilities

The right hemisphere has been called nondominant or minor hemisphere --- nonverbal and artistic expressions

VI. THE CEREBRAL WHITE MATTER

• Association fibres – connecting areas same hemisphere• Commissural fibres – connecting areas opposite hemisphere• Projection fibres – connecting areas with spinal cord & vv.

VII. THE BASAL NUCLEI (GANGLIA)Basal ganglia in red

Diencephalon in green

VII. THE BASAL NUCLEI (GANGLIA)Basal ganglia in red

Diencephalon in green

VII. THE BASAL NUCLEI (GANGLIA)

Head of Caudate nucleusClaustrum

PutamenGlobus pallidus

Tail of Caudate nucleusAmygdala (in temporal lobe)

Lentiform nucleus

Function of Basal nuclei : Planning of motor movements

NAME THE BASAL GANGLIA (NUCLEI)

VII. THE BASAL NUCLEI (GANGLIA)

Head of Caudate nucleusClaustrum

PutamenGlobus pallidus

Tail of Caudate nucleusAmygdala (in temporal lobe) or Amygdaloid body

Lentiform nucleus

THALAMUS

PLEASE ORIENTATE YOURSELVESON THE FOLLOWING STRUCTURES

VENTRICLES

DIENCEPHALONEpithalamus

Dorsal thalamusHypothalamusSubthalamus

The Diencephalon (green) develops from

the Proscephalon and is hidden in the Cerebrum

INTRODUCTIONDIENCEPHALON

ASSOC PROF. HAMIADJI T. 24-11-2011.

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Diencephalon

• The Diencephalon is the part of the Cerebrum that is hidden.

• The Diencephalon is the crossing point of

the cerebral cortex, pituitary gland, and the spinal cord.

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DiencephalonOn a sagittal section of the cerebrum

the borders of the diencephalon are:• Choroid plexus of the 3rd ventricle• Habenular commissure• Epihysis (pineal body)• Posterior commissure…………. A hypothetic line ………….• Mammillary body• Tuber cinereum• Hypophysis (pituitary gland)• Optic chiasm…………. A hypothetic line ………….• Interventricular foramen (Monroe)

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The diencephalon isdivided into 4 parts:1. Epithalamus2. Thalamus (dorsal) &

Metathalamus3. Hypothalamus4. Subthalamus

Epithalamus

Dorsal thalamus

Hypothalamus

Epithalamus forms the roof of Diencephalon & includes:•Striae medullaris thalami•Habenula & habenular commissure•Peneal body•Posterior commissure

Diencephalon 5

Thalamus• Is the largest subdivision of the

diencephalon.• Is a major integrated station that

is intercalated between many subcortical structures.

• All sensory impulses except olfaction are relayed before reaching the cerebral cortex.

• Is an ovoid structure at the side of the 3rd ventricle (small anteriorly; big posteriorly).

• Lateral surface related to the internal capsule.

• Medial surface related to 3rd ventricle.

• Superior surface related to lateral ventricles & choroid plexus (med).

• Inferior surface related to the brainstem tegmentum.

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The thalamus consists chiefly of gray

substance.Its gray substance is

incompletely subdivided into three

parts—anterior, medial, and lateral—by

a white layer, the medial medullary

lamina.Fibres (axons &

dendrites) coming into and out are called thalamic radiation

Phylogenesis: anterior – medial (old); lateral nuclei (new)

Thalamus 7

NUCLEI OF THE THALAMUS

Basal gangliaArea6 & difuse frontal cortex

Cerebellum & Basal ganglia

Area 4

Medial lemniscus & Spinal lemniscus

Area 3,1 & 2 Trigeminothalamic tract

Area 3,1 & 2

Optic tractArea 17

Inferior colliculus &Lateral lemniscus

Area 41, 42

Areas 18, 19Inferior parietal

lobule

Mammillothalamic tract, fornix

Cingulate gyrus

Amygdaloid complex & Temporal neocortex

Prefrontal cortex

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Structure / Nuclei

Function Destination

Anterior group Part of limbic system

Cingulum

Medial group Integrates sensory info.

Frontal lobe

Ventral group Projects sensory info.

Primary sensory cortex

Posterior group / pulvinar

Integrates sensory info.

Association areas of cortex

LGB Projects visual info. Visual cortex

MGB Projects auditory info.

Auditory cortex

NUCLEI OF THE THALAMUS 9

SubthalamusFlanks the hypothalamus laterally and thus is not

visible, is a significant subcortical station in the motor activities of voluntary muscles.

Functionally it belongs to the extrapyramidal system

Lesion results in hemiballism. An involuntary, forcefull, sudden, purposeless movement of

contra-lateral half of the body.Assoc. Prof. dr. Hamiadji T.

25.11.20011.

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HypothalamusSeparate lecture

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THANK YOU

THE BRAINSTEMA FIXED LEARNING MODULE

COMPILED BYAssoc Prof dr Hamiadji Tanuseputro

STUDY THEBRAINSTEM

LONGITUDINALLY

THE BRAINSTEM

Rhomboid Fossa (fossa rhomboidea; “floor” of the fourth ventricle)—The anterior part of the fourth ventricle is named, from its shape, the rhomboid fossa, and its anterior wall, formed by the back of the pons and medulla oblongata, constitutes the floor of the fourth ventricle.

DESCRIBE THE RHOMBOIDFOSSA

DEVELOPMENT OF THE BRAIN

Medulla

Pons

Midbrain

CRANIAL NERVES NUCLEI

VIII

V

XIX

IX

IV

III

VII

VI

TRY TO IDENTIFYTHE RESPECTIVE

CRANIAL NERVES.

CRANIAL NERVES NUCLEI

VII

VI

VIV

III

VIII

IX

XXI

XII

TRY TO IDENTIFYTHE RESPECTIVE

CRANIAL NERVES.

NOTESNOTES:* From the brainstem emerge cranial nerves III to XII.* The brainstem is located inferior to the Tentorium Cerebelli.* The brainstem is the site of crossing of the Cerebrum (rostrally),

the Cerebellum (dorsally) and the Spinal Cord (caudally).* The brainstem is the site of communication of the Subarachnoid

space and the Ventricular System through the foramina of Luschka & Magendie.

* The brainstem contains the Vital Centres (reticular system).

THE VENTRICULAR SYSTEM

That portion of the fluid formed in the lateral ventricles escapes by the foramen of Monro into the third ventricle and thence by the

aqueduct into the fourth ventricle. Likewise an ascending current of fluid apparently occurs in the central canal of the spinal cord; this, representing a possible product of the ependyma, may be

added to the intraventricular supply.

DESCRIBETHE CSF

CIRCULATION

THANK YOU

• A cheerful heart is good medicine, but a crushed spirit dries up the bones.

• The fear of the Lord teaches a man wisdom, and humility comes before honour.

• Many are the plans in a man’s heart, but it is the Lord’s purpose that prevails.

Assoc. Prof. dr. Hamiadji T. 25.11.2011