Download Gross Brain Overview: Part II

Gross Brain Overview: Part II
Basic Neuroscience
James H. Baños, Ph.D.
Overview
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Organization
Morphology
 Developmental/Evolutionary
 Cytoarchitectural
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3-D Orientation to Internal Structures
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How do we organize and characterize different
parts of the brain?
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How do we organize and characterize different
parts of the brain?
Morphology
 Developmental/Evolutionary Origins
 Cytoarchitecture
 Function
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Morphology:
External Features
Frog
Rat
What’s changing?
Cat
Monkey
Human
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Sulci - The “valleys” on the surface of the
brain
Gyri - The “Hills”
The term “gyrus” is sometimes used broadly and doesn’t always
refer to a single well-defined ridge on the surface of the brain.
The distinctions between large gyri are sometimes better seen in
coronal sections.
Hemispheres
Longitudinal
Fissure
Lobes
Central (Rolandic) Sulcus
Lateral (Sylvian) fissure
Parieto-occipital fissure
Lobes
Frontal
Parietal
Temporal
Occipital
Cingulate Gyrus
“Limbic Lobe”
Brain Stem
Thalamus
Hypothalamus
Midbrain
Pons
Medulla
Cerebellum: Superior Aspect
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Ant
2 Hemispheres
Vermis
Cerebellum: Posterior Aspect
Anterior Lobe
Primary Fissure
Posterior Lobe
Hemisphere
Vermis Hemisphere
Cerebellum: Mid-Saggital
Anterior Vermis
Posterior Vermis
Developmental and
Evolutionary Origins: The
“Cephalons”
Developmental Origins
Three Vessicle Stage
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Areas of the Brain can be
characterized by the
embryonic origins of the
tissue.
Nervous system begins as a
tube that differentiates into
three vessicles:
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Prosencephalon
Mesencephalon
Rhombencephalon
Developmental Origins

Five Vessicle Stage
Prosencephalon differentiates:
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Rhombencehphalon
differentiates
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Telencephalon -- beginnings of
hemispheres
Diencephalon
Metencephalon
Meyelencephalon
We use this terminology to
describe the parts of the brain
that develop from these
vessicles
Developmental Origins
Prosencephalon
(forebrain)
Telencephalon
(endbrain)
Cerebral Cortex
Basal Ganglia
Limbic System
Hippocampus
Diencephalon
(interbrain)
Thalamus
Hypothalamus
Mesencephalon
Mesencephalon
Midbrain
Rhombencephalon
(hindbrain)
Metencephalon
Cerebellum
Pons
Myelencephalon
Medulla
Organization

Telencephalon
Cortex
 Basal Ganglia
 Limbic System
 Hippocampus

Organization

Diencephalon
Thalamus
 Hypothalamus

Organization

Mesencephalon

Midbrain
Organization

Metencephalon
Cerebellum
 Pons
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Organization

Myelencephalon

Medulla
Cytoarchitectural
Organization
Brodmann’s Areas
Internal Structure
Major Internal Structures
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Ventricular System
Amygdala (helpful landmark)
Thalamus/Hypothalamus/brain stem
Basal Ganglia
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Hippocampal formation
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Caudate Nucleus
Putamen
Globus Pallidus
Hippocampus
Fimbria
Fornix
Major white matter landmarks
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Corpus callosum
Internal capsule
Evolution and Development
Frog
Rat
Cat
Monkey
Human
Evolution and Development
Frog
Rat
Cat
Monkey
Human
?
Evolution and Development
Ventricles
Basal Ganglia
Hippocampus
Evolution and Development
Why not the thalamus?
The Ventricular System
Ventricles
Lateral Ventricles
Third Ventricle
Fourth Ventricle
Ventricles

Ventricles are connected (communicate)
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Intraventricular Foramina (of Monroe)
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Cerebral Aqueduct (of Sylvius)
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Third Ventricle to Fourth
Long, thin channel
Foramen of Magendie
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Lateral Ventricles to Third Ventricle
Wide, oval hole
Median aperture -- Fourth ventricle to subarachnoid space
Foramina of Luschka
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Lateral apertures -- Fourth ventricle to subarachnoid space
Ventricles
Foramen of Monroe
Aqueduct of Sylvius
Foramina of Luschka
Foramen of Magendie
Ventricles
Choroid Plexus and CSF

Choroid Plexus
Spongy tissue located in the ventricles
 Rich capillary bed
 Pia Mater
 Choroid endothelial cells

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Produces CSF
About .35 ml per minute
 Total volume 70-120 ml

Choroid Plexus
CSF Flow
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Lateral ventricles
Foramina of Monroe
3rd ventricle
Aqueduct of Sylvius
4th Ventricle
Foramen of Magendie/foramina of Lushka
Subarachnoid Space
Arachnoid granulations (absorption)
Superior sagittal sinus
CSF Flow
CSF Absorption

CSF flows to the dorsal surface of the
brain, where arachnoid granulations form
a one-way valve and let the excess CSF
enter the veinous drainage of the superior
sagittal sinus
CSF Absorption
Arachnoid Granulations
Ventricular System plus Amygdala
Ventricular System plus Thalamus
Ventricular System plus Thalamus
Ventricles, Brainstem, and Thalamus
Basal Ganglia -- Caudate Nucleus
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Basal Ganglia
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Caudate Nucleus
Putamen
Globus Pallidus
Sometimes Amygdala
Basal Ganglia -- Caudate Nucleus
Basal Ganglia -- Caudate Nucleus
Basal Ganglia -- Putamen & Globus
Pallidus
Basal Ganglia
Basal Ganglia
Hippocampus
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Hippocampal
formation
Fimbria
Fornix
Anterior
Commissure
Amygdala
Hippocampus
Hippocampus
Coming up…
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Circulation and Stroke
Development
Spinal cord
Basic Spinal Pathways