Post on 06-May-2015
description
CEREBELLUM
Presented by:-Mr. Suresh Kumar SharmaRN, ACCN, MSN(PSYCHIATRY)
BY
1
DIVISIONS OF THE BRAIN
Forebrain Midbrain Hindbrain
CerebrumThalamus
Hypothalamus
Cerebral peduncleTectum
Brainstem
CerebellumPons
Medulla Oblongata
Sagittal View of the Brain3
FUNCTIONAL REGIONS OF THE BRAIN
The Cerebrum The Cerebellum The Brain Stem
4
ANATOMY OF THE CEREBRUM
Cerebral Hemispheres(View from Above)
LeftRight5
FUNCTIONS OF THE CEREBRUM
Frontal lobe:•Voluntary movement•Higher intellectual functions
Temporal lobe:•Speech & Sound•Complex visual perceptions
Occipital lobe:•Vision
Parietal lobe:•Sensory processes•Attention•Language
6
CONTRALATERAL FUNCTION OF THE CEREBRUM
7
ANATOMY OF THE CEREBELLUM
1. Left Cerebellar Hemisphere
2. Right Cerebellar Hemisphere
3. Vermis
21
3
Spinal cord
8
CEREBELLAR FUNCTIONS
9
ANATOMY OF THE BRAINSTEM
10
FUNCTION OF THE BRAINSTEM
Midbrain:•Visual & auditory processing and reflexes•Fine-tuning of voluntary movements
Pons:•Relay station for cerebellum•Control of sub-conscious movement
Medulla Oblongata:•Control of cardiovascular functions•Control of respiration•Control of gastrointestinal functions
11
CEREBELLUMCEREBELLUM
12
GROSS ANATOMY OF CEREBELLUMGROSS ANATOMY OF CEREBELLUM
Location: The term cerebellum is from
“Latin meaning” the little brain.
part of the hindbrain situated in the posterior cranial fossa.
behind the Pons and medulla oblongata, separated from two structures by the cavity of fourth ventricle.
It is covered by tentorium cerebelli and is connected to brain stem by three cerebellar peduncles.
In adults the weight ratio between cerebellum and cerebrum is 1:10,Infants 1:20
13
Consists of two laterally, large hemisphere which are united by midline vermis.
Cerebellar surface is divided by numerous curve transverse fissures giving it a laminated appearance
One conspicious fissure “horizontal fissure" extends around dorsolateral border of each hemisphere from middle Cerebellar peduncle to vallecula, separating superior and inferior surface
Horizontal fissure
Vermis
Hemisphere
Superior surface
Anatomy of cerebellum......contd.
14
The deepest fissure in the vermis is primary fissure, which curves ventrolaterally in the superior surface of the cerebellum to meet horizontal fissure.
Primary fissure divides the cerebellum into anterior and posterior lobe.
Primary fissure
Anterior lobe
Posterior lobePrimary fissure
External surface of cerebellum
15
Horizontal fissure
verm
is
Primary fissure
Anterior
lobe
Posterior lob
e
Hemisphere
External surface of cerebellum
16
Fourth ventricle
Arbor vitae cerebelli
Arbor vitae •In Latin “ tree of life” it is the white matter of the cerebellum.
•It is so called because of the tree like appearance.
•It brings sensory and motor sensation to and from cerebellum.
17
Vermis
Hemisphere
Parts of the cerebellum
18
LOBES OF CEREBELLUMDivisions of lobesAnatomical
Flocculonodular lobe
Anterior lobe
Posterior lobe
Anterior lobe
Posterior lobe
Flocculonodular lobe
Inferior surface
Superior surface
Anterior lobe
Posterior lobe19
Functional(Evolutionary)
Paleocerebellum
Neocerebellum
Archicerebellum
Division of lobes…..contd.
20
Archi-cerebellum posterior lobe (Vestibular part) •It is formed of the flocculo-nodular lobe + associated Fastigial nuclei, lying on inf. Surface in front of postero-lateral fissure. •Embryo logically, it is the oldest part of cerebellum. •It receives afferent Fibres. From vestibular apparatus of internal ear Via vestibulo-cerebellar tracts. •It is concerned with equilibrium
Neocerebellum
Archicerebellum
Paleocerebellum 21
Paleo-cerebellum (spinal part) •it is formed of midline vermis + surrounding paravermis + globose & emboliform nuclei.
•It receives afferent proprioceptive impulses from Ms.& tendons Via spinocerebellar tracts (dorsal & ventral) mainly.
•it sends efferent to red nucleus of midbrain.
•it is concerned with muscle tone & posture.
Paleocerebellum
22
Neo-cerebellum (cerebralpart) •It is the remaining largest part of cerebellum.•It includes the most 2-cerebellar hemispheres + dendate nuclei.•It receives afferent impulses from the cerebral cortex + Pons Via cerebroponto-cerebellar pathway.•it sends efferent to Ventro lateral nucleus of thalamus.•it controls voluntary movements (muscle coordination).
Neocerebellum
23
ArchicerebellumNodulus
Archicerebellumflocculus
Palaeocerebellum
Neocerebellum
Spinocerebellum
Pontocerebellum
Vestibulocerebellum
Summary of classification
24
Classification by Classification by phylogeneticphylogenetic
Ontogenic developmentOntogenic development• ArchicerebellumArchicerebellum• PaleocerebllumPaleocerebllum• NeocerebellumNeocerebellum
Classification by Afferent Classification by Afferent ConnectionConnection
• VestibulocerebellumVestibulocerebellum•SpinocerebellumSpinocerebellum•Ponto cerebellumPonto cerebellum
Classification by Efferent Classification by Efferent Connection Connection
•VermisVermis•Paravermis RegionParavermis Region•Cerebellar HemisphereCerebellar Hemisphere
25
26
INTERNAL STRUCTURE:-INTERNAL STRUCTURE:- Cerebellum consists of outer
layer of grey matter known as cortex and inner layer of white matter known as medulla.
The medullary core is composed of incoming and outgoing fibres projecting to and from the Cerebellar cortex.
Medullary core also contain the nucleuses of the cerebellum which are four in number.
27
Cortex Medulla Structure of cerebellum
28
Structure of Cerebellar……contd.Cerebellar Cortex:- Cerebellar Cortex:-
Molecular LayerMolecular LayerPurkinje Cell LayerPurkinje Cell LayerGranular LayerGranular Layer
Corpus Medullare (Medullary Center)Corpus Medullare (Medullary Center)
Deep Cerebellar Nuclei:-Deep Cerebellar Nuclei:-Fastigial NucleiFastigial NucleiNucleus InterpositusNucleus InterpositusEmboliform NucleusEmboliform NucleusGlobose NucleusGlobose NucleusDentate NucleusDentate Nucleus
29
Dentate nucleus
Emboliform nucleus
Globose nucleus
Fastigial nucleusNucleus Interpositus
Deep nucleuses of cerebellum
30
White matter of the cerebellum
Consists of three types of nerve fibres in the white matter
A.Axons of purkinje cells The only axons to leave Cerebellar cortex to end in deep Cerebellar nuclei specially dendate nucleus.
B.Mossy fibres They end in the granular layer.
C.Climbing fibres They end in the molecular layer
31
The internal circuity of cerebellum:- Don't leave the cerebellum, interconnect different regions of cerebellum. Some connect the same side. Some connect the two Cerebellar hemisphere
The Cerebellar efferent via middle Cerebellar peduncle(MCP) and inferior Cerebellar peduncle (ICP)
The Cerebellar afferent via superior Cerebellar peduncle(SCP) and from Fastigial from inferior Cerebellar peduncle(ICP)
White matter of cerebellum
32
The cerebellum is connected toBrain stem by three peduncles
Midbrain Middle Cerebellar
peduncle
PonsInferior Cerebellar peduncle
Medulla oblongata
33
Superior Cerebellar peduncle
Peduncles of the cerebellum
34
Fibres entering and leaving through Cerebellar peduncles
1.Superior cerebellar peduncle
A.Fibres entering the cerebellum 1. Ventral spino-cerebellar tract 2. Rostral spino-cerebellar tract 3. Tecto-cerebellar fibres 4. Rubro-cerebellar fibres 5. Trigemino-cerebellar fibres 6. Hypothalamo-cerebellar fibres 7. Coerulo-cerebellar fibres
B.Fibres leaving the cerebellum 1. Cerebello-rubral fibres 2. Cerebello-thalamic fibres 3. Cerebello-reticular fibres 4. Cerebello-olivary fibres 5. Cerebello-nuclear fibres 6. Some fibres to hypothalamus and thalamus
Superior cerebellar peduncle
35
2.Middle cerebellar pedunclePontocerebellar fibres
3.Inferior cerebellar peduncle
A.Fibres entering cerebellum 1. Posterior spino cerebellar tract 2. Cuneo-cerebellar tract 3. Olivo-cerebellar fibres 4. Reticulo-cerebellar fibres 5. Vestibulo-cerebellar fibres 6. Anterior external arcuate fibres 7. Fibres of striae medullaries 8. Trigemino-cerebellar fibres
B.Fibres Leaving the cerebellum 1. Cerebello-olivary fibres 2. Cerebello-vestibular fibres 3. Cerebello spinal and cerebello reticular fibres
Middle cerebellar peduncle
Inferior cerebellar peduncle
36
CT SCAN OF BRAIN WITH CEREBELLUM
37
MRI OF BRAIN WITH CEREBELLUM
38
Blood supply to brain
• Arch of aorta1. Brachiocephalic trunk
i. right common carotid artery
2. Left common carotid artery
3. Left subclavian artery
• right common carotid artery1. External carotid artery
2. Internal carotid artery
39
Blood supply to brain• Anterior cerebral arteries –2• Internal carotid arteries –2• Anterior communicating artery-1• Posterior communicating artery-1• Posterior cerebral arteries -2• Basilar artery-2
40
Circulus arterious(circle of Willis)
circle of Willis
41
Blood supply to cerebellum• Superior surface of cerebellum – superior
Cerebellar branches of basilar artery(SCA)
• Inferior surface– Anterior part -(AICA)
• Anterior inferior Cerebellar
branches of basilar artery
– Posterior part- (PICA)• Posterior inferior Cerebellar• branches of basilar artery
42
Functions of cerebellum
43
44
Maintenance of EquilibriumMaintenance of Equilibrium - balance, posture, eye movement - balance, posture, eye movement
45
Motor Leaning – Motor SkillsMotor Leaning – Motor Skills
Coordination of half-automatic movement Coordination of half-automatic movement of walking and posture maintenanceof walking and posture maintenance - posture -gait - posture -gait
46
Adjustment of Muscle ToneAdjustment of Muscle Tone
,
47
Cognitive FunctionCognitive Function
48
CEREBELLAR FUNCTION TEST• FINGER TO FINGER FINGER TO NOSE
TEST TEST
49
CEREBELLAR FUNCTION TEST• ROMBERG TEST TANDOM TEST
50
Ataxia:Ataxia: incoordination of movementincoordination of movement - decomposition of movement- decomposition of movement - dysmetria, past-pointing- dysmetria, past-pointing - dysdiadochokinesia- dysdiadochokinesia - rebound phenomenon of Holmes- rebound phenomenon of Holmes - gait ataxia, truncal ataxia, titubation- gait ataxia, truncal ataxia, titubationIntention TremorIntention TremorHypotonia,Hypotonia, NystagmusNystagmus
Archicerebellar Lesion: Archicerebellar Lesion: medulloblastomamedulloblastomaPaleocerebellar LesionPaleocerebellar Lesion: gait disturbance: gait disturbanceNeocerebellar LesionNeocerebellar Lesion: hypotonia, ataxia, tremor: hypotonia, ataxia, tremor
Syndromes
51
Cerebellar Cerebellar Ataxia Ataxia
Ataxic gait and position: Ataxic gait and position: Left cerebellar tumorLeft cerebellar tumor
a. Sways to the right ina. Sways to the right in standing positionstanding position
b. Steady on the b. Steady on the right legright leg
c. Unsteady on the c. Unsteady on the left legleft leg
d. ataxic gaitd. ataxic gait
52
Cerebellar Cerebellar Medulloblastoma Medulloblastoma
Cerebellar tumors on Cerebellar tumors on
vermisvermis
- Truncal Ataxia- Truncal Ataxia
- Frequent Falling- Frequent Falling
The child in this picture:The child in this picture:
- - would not try to stand would not try to stand unsupportedunsupported
- would not let go of the - would not let go of the
bed railbed rail if she was stood on the if she was stood on the floor.floor. 53
.
54
NOW TIME FOR ASSIGNMENT
55
WRITE DOWN DIFFERENT DISEASES RELATED TO THE CEREBELLUM FUNCTION LOST???????