gross brain overview: part ii basic neuroscience james h. baños, ph.d
TRANSCRIPT
Gross Brain Overview: Part II Gross Brain Overview: Part II
Basic NeuroscienceBasic Neuroscience
James H. Baños, Ph.D.James H. Baños, Ph.D.
OverviewOverview
OrganizationOrganization Morphology Morphology Developmental/EvolutionaryDevelopmental/Evolutionary CytoarchitecturalCytoarchitectural
3-D Orientation to Internal 3-D Orientation to Internal StructuresStructures
How do we organize and characterize different How do we organize and characterize different parts of the brain?parts of the brain?
How do we organize and characterize different How do we organize and characterize different parts of the brain?parts of the brain? Morphology Morphology Developmental/Evolutionary OriginsDevelopmental/Evolutionary Origins CytoarchitectureCytoarchitecture FunctionFunction
Morphology: Morphology: External FeaturesExternal Features
Frog
Rat
Cat
MonkeyHuman
What’s changing?
Sulci - The “valleys” on the surface Sulci - The “valleys” on the surface of the brainof the brain
Gyri - The “Hills”Gyri - The “Hills”
The term “gyrus” is sometimes used broadly and doesn’t alwaysrefer to a single well-defined ridge on the surface of the brain.The distinctions between large gyri are sometimes better seen incoronal sections.
HemispheresHemispheres
LongitudinalFissure
LobesLobes
Central (Rolandic) Sulcus
Lateral (Sylvian) fissure
Parieto-occipital fissure
LobesLobes
Frontal
Parietal
Temporal
Occipital
Cingulate Gyrus“Limbic Lobe”
Brain StemBrain Stem
Thalamus
Hypothalamus
Midbrain
Pons
Medulla
Cerebellum: Superior Cerebellum: Superior AspectAspect
Ant
2 Hemispheres2 Hemispheres VermisVermis
Cerebellum: Posterior Cerebellum: Posterior AspectAspect
Hemisphere HemisphereVermis
Posterior Lobe
Anterior Lobe
Primary Fissure
Cerebellum: Mid-Cerebellum: Mid-SaggitalSaggital
Anterior Vermis
Posterior Vermis
Developmental and Developmental and Evolutionary Origins: Evolutionary Origins:
The “Cephalons”The “Cephalons”
Developmental OriginsDevelopmental Origins Areas of the Brain can be Areas of the Brain can be
characterized by the characterized by the embryonic origins of the embryonic origins of the tissue.tissue.
Nervous system begins as Nervous system begins as a tube that differentiates a tube that differentiates into three vessicles:into three vessicles: ProsencephalonProsencephalon MesencephalonMesencephalon RhombencephalonRhombencephalon
Three Vessicle Stage
Developmental OriginsDevelopmental Origins Prosencephalon Prosencephalon
differentiates:differentiates: Telencephalon -- beginnings Telencephalon -- beginnings
of hemispheresof hemispheres DiencephalonDiencephalon
Rhombencehphalon Rhombencehphalon differentiatesdifferentiates MetencephalonMetencephalon MeyelencephalonMeyelencephalon
We use this terminology to We use this terminology to describe the parts of the describe the parts of the brain that develop from brain that develop from these vessiclesthese vessicles
Five Vessicle Stage
Developmental OriginsDevelopmental Origins
Cerebral CortexBasal GangliaLimbic SystemHippocampus
Telencephalon(endbrain)
ThalamusHypothalamus
Diencephalon(interbrain)
Prosencephalon(forebrain)
Midbrain
Mesencephalon
Mesencephalon
CerebellumPons
Metencephalon
Medulla
Myelencephalon
Rhombencephalon(hindbrain)
OrganizationOrganization
TelencephalonTelencephalon CortexCortex Basal GangliaBasal Ganglia Limbic SystemLimbic System HippocampusHippocampus
OrganizationOrganization
DiencephalonDiencephalon ThalamusThalamus HypothalamusHypothalamus
OrganizationOrganization
MesencephalonMesencephalon MidbrainMidbrain
OrganizationOrganization
MetencephalonMetencephalon CerebellumCerebellum PonsPons
OrganizationOrganization
MyelencephalonMyelencephalon MedullaMedulla
Cytoarchitectural Cytoarchitectural OrganizationOrganization
Brodmann’s AreasBrodmann’s Areas
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Internal Internal StructureStructure
Major Internal Major Internal StructuresStructures
Ventricular SystemVentricular System Amygdala (helpful landmark)Amygdala (helpful landmark) Thalamus/Hypothalamus/brain stemThalamus/Hypothalamus/brain stem Basal GangliaBasal Ganglia
Caudate NucleusCaudate Nucleus PutamenPutamen Globus PallidusGlobus Pallidus
Hippocampal formationHippocampal formation HippocampusHippocampus FimbriaFimbria FornixFornix
Major white matter landmarksMajor white matter landmarks Corpus callosumCorpus callosum Internal capsuleInternal capsule
Evolution and Evolution and DevelopmentDevelopment
Frog
Rat
Cat
MonkeyHuman
Evolution and Evolution and DevelopmentDevelopment
Frog
Rat
Cat
MonkeyHuman
?
Evolution and Evolution and DevelopmentDevelopment
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Ventricles
Basal Ganglia
Hippocampus
Evolution and Evolution and DevelopmentDevelopment
Why not the thalamus?
The Ventricular The Ventricular SystemSystem
VentriclesVentricles
Lateral Ventricles
Third Ventricle
Fourth Ventricle
VentriclesVentricles
Ventricles are connected (communicate)Ventricles are connected (communicate) Intraventricular Foramina (of Monroe)Intraventricular Foramina (of Monroe)
Lateral Ventricles to Third VentricleLateral Ventricles to Third Ventricle Wide, oval holeWide, oval hole
Cerebral Aqueduct (of Sylvius)Cerebral Aqueduct (of Sylvius) Third Ventricle to FourthThird Ventricle to Fourth Long, thin channelLong, thin channel
Foramen of MagendieForamen of Magendie Median aperture -- Fourth ventricle to subarachnoid spaceMedian aperture -- Fourth ventricle to subarachnoid space
Foramina of LuschkaForamina of Luschka Lateral apertures -- Fourth ventricle to subarachnoid Lateral apertures -- Fourth ventricle to subarachnoid
spacespace
VentriclesVentricles
Foramen of Monroe
Aqueduct of Sylvius
Foramina of Luschka
Foramen of Magendie
VentriclesVentricles
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VentriclesVentricles
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VentriclesVentricles
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VentriclesVentricles
Choroid Plexus and CSFChoroid Plexus and CSF
Choroid PlexusChoroid Plexus Spongy tissue located in the ventriclesSpongy tissue located in the ventricles Rich capillary bedRich capillary bed Pia MaterPia Mater Choroid endothelial cellsChoroid endothelial cells
Produces CSFProduces CSF About .35 ml per minuteAbout .35 ml per minute Total volume 70-120 mlTotal volume 70-120 ml
Choroid PlexusChoroid Plexus
CSF FlowCSF Flow Lateral ventriclesLateral ventricles Foramina of MonroeForamina of Monroe 3rd ventricle3rd ventricle Aqueduct of SylviusAqueduct of Sylvius 4th Ventricle4th Ventricle Foramen of Magendie/foramina of LushkaForamen of Magendie/foramina of Lushka Subarachnoid SpaceSubarachnoid Space Arachnoid granulations (absorption)Arachnoid granulations (absorption) Superior sagittal sinusSuperior sagittal sinus
CSF FlowCSF Flow
CSF AbsorptionCSF Absorption
CSF flows to the dorsal surface of CSF flows to the dorsal surface of the brain, where the brain, where arachnoid arachnoid granulations granulations form a one-way valve form a one-way valve and let the excess CSF enter the and let the excess CSF enter the veinous drainage of the superior veinous drainage of the superior sagittal sinussagittal sinus
CSF AbsorptionCSF Absorption
Arachnoid GranulationsArachnoid Granulations
Ventricular System plus AmygdalaVentricular System plus Amygdala
Ventricular System plus ThalamusVentricular System plus Thalamus
Ventricular System plus ThalamusVentricular System plus Thalamus
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Ventricles, Brainstem, and Ventricles, Brainstem, and ThalamusThalamus
Ventricles, Brainstem, and Ventricles, Brainstem, and ThalamusThalamus
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Basal Ganglia -- Caudate NucleusBasal Ganglia -- Caudate Nucleus
Basal GangliaBasal Ganglia Caudate NucleusCaudate Nucleus PutamenPutamen Globus PallidusGlobus Pallidus Sometimes Sometimes
AmygdalaAmygdala
Basal Ganglia -- Caudate NucleusBasal Ganglia -- Caudate Nucleus
Basal Ganglia -- Caudate NucleusBasal Ganglia -- Caudate Nucleus
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Basal Ganglia -- Caudate NucleusBasal Ganglia -- Caudate Nucleus
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Basal Ganglia -- Putamen & Basal Ganglia -- Putamen & Globus PallidusGlobus Pallidus
Basal Ganglia -- Putamen & Basal Ganglia -- Putamen & Globus PallidusGlobus Pallidus
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Basal GangliaBasal Ganglia
Basal GangliaBasal Ganglia
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Basal GangliaBasal Ganglia
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Internal CapsuleInternal Capsule
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HippocampusHippocampus
Hippocampal Hippocampal formationformation
FimbriaFimbria FornixFornix Anterior Anterior
CommissureCommissure AmygdalaAmygdala
HippocampusHippocampus
HippocampusHippocampus
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Coming up…Coming up…
Spinal cordSpinal cord Basic Spinal PathwaysBasic Spinal Pathways