Download The Telencephalon

The Telencephalon
SHANDONG UNIVERSITY
Liu Zhiyu
General Appearance of Cerebrum
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The telencephalon consists of right and
left cerebral hemisphere, partially
separated by cerebral longitudinal
fissure
In the depths of the fissure, the corpus
callosum connects the hemispheres
across the midline
The cerebral transverse fissure
intervenes between the hemispheres
and the cerebellum
Each hemisphere has three surfaces:
superolateral, medial and inferior
Main Sulci
Three principal sulci
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Central sulcus
Lateral sulcus
Parietooccipital sulcus
Central sulcus
Lateral sulcus
Parietooccipital sulcus
Lobes of Cerebral Hemisphere
Five lobes
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Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Insular lobe
Insular lobe
Sulci and gyri of frontal lobe
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Precentral sulcus
Precentral gyrus
Superior frontal sulcus
Inferior frontal sulcus
Superior frontal gyrus
Middle frontal gyrus
Inferior frontal gyrus
Sulci and gyri of frontal lobe
Precentral gyrus
Precentral sulcus
Superior frontal sulcus
Inferior frontal sulcus
Superior, middle
and inferioe frontal
gyri
Sulci and Gyri of Parietal Lobe
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Postcentral sulcus
Postcentral gyrus
Intraparietal sulcus
Superior parietal lobule
Inferior parietal lobule
Supramarginal gyrus
Angular gyrus
Sulci and Gyri of Parietal Lobe
Postcentral gyrus
Postcentral sulcus
Superior parietal lobule
Intraparietal sulcus
Supramarginal gyrus
Angular gyrus
Sulci and Gyri of Temporal Lobe
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Superior temporal sulcus
Inferior temporal sulcus
Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
Transverse temporal gyri
Sulci and Gyri of Temporal Lobe
Superior temporal sulcus
Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
Inferior temporal sulcus
Sulci and Gyri of Temporal Lobe
Transverse temporal gyri
Sulci and gyri of Superolateral surface
Precentral gyrus
Precentral sulcus
Superior frontal sulcus
Postcentral gyrus
Postcentral sulcus
Intraparietal sulcus
Superior parietal lobule
Inferior frontal sulcus
Superior,
middle
and inferior
frontal
gyri
Supramarginal gyrus
Angular gyrus
Superior temporal sulcus
Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
Inferior temporal sulcus
Sulci and Gyri of Medial Surface
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Corpus callosum
Callosal sulcus
Cingulate gyrus
Cingulate sulcus
Marginal ramus
Paracentral lobule
Calcarine sulcus
Cuneus
Lingual gyrus
Sulci and Gyri of Medial Surface
Callosal sulcus
cingulate gyrus
Corpus callosum
Paracentral lobule
Marginal ramus
Cingulate sulcus
Parietooccipital
sulcus
Cuneus
Calcarine
sulcus
Lingual gyrus
Sulci and Gyri of Inferior Surface
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Olfactory bulb
Olfactory tract
Olfactory trigone
Anterior perforated substance
Collateral sulcus
Occipitotemporal sulcus
Medial occipitotemporal gyrus
Lateral occipitotemporal gyrus
Hippocampal sulcus
Parahippocampal gyrus
Uncus
Hippocampus
Dentate gyrus
Sulci and Gyri of Inferior Surface
Olfactory bulb
Olfactory tract
Olfactory trigone
Uncus
Ant. Perforated substance
Occipitotemporal sulcus
Parahippocampalgyrus
Collateral sulcus
Lateral occipitotemporal
gyrus
Medial occipitotemporal
gyrus
Sulci and Gyri of Inferior Surface
Hippocampus
Dentate gyrus
Hippocampal
formation
Histology of Cerebral Cortex
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Archicortex (hippocampal formation)
Paleocortex (rhinencephalon)
Neocortex (most of cerebral cortex)
3 cell layers
6 cell layers
Functional Location of Cerebral Cortex
First Somatic Motor Area
Position:
Located in precentral gyrus
and anterior portion of
paracentral lobule
First Somatic Motor Area
Characters
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Representation is inverted, but
head and face are upright
A body part is represented by a
cortical area proportional to its
use rather than its size
Receiving fibers from postcentral
gyrus, ventral anterior, ventral
lateral and ventral posterior
nuclei
Sending out fibers to form
pyramidal tract, controlling
voluntary movements
First Somatic Motor Area
First Somatic Motor Area
First Somatic Sensory Area
Position:
Lies in postcentral gyrus and
posterior portion of paracentral
lobule
First Somatic Sensory Area
Characters
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Sensory representation, like
motor area, is crossed and
inverted
Receiving fibers from ventral
posterior nucleus
Interpret sensation from
opposite side of body
First Somatic Sensory Area
Visual Area
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Lie on either side of calcarine
sulcus in medial surface of
occipital lobe
Visual cortex of one
hemisphere receives
impression from temporal part
of retina of same side and
nasal part of opposite side
Lesions of visual cortex
produce contralateral
homonymous visual field
defections
Auditory Area
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Located in transverse
temporal gyri
Receive auditory
information from both
ears
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Vestibular area: located in
front of superior temporal
gyrus
Olfactory area: located
near the uncus
Taste area: located at
frontal operculum
Language Area
It is dominant in left hemisphere in right-handed person
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Motor speech area
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Writing area
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Located in posterior portion of middle
frontal gyrus
Damage: agraphia
Auditory speech area
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Located in posterior portion of inferior
frontal gyrus
Damage: motor aphasia
Located in posterior portion of superior
temporal gyrus
Lesion: sensory aphasia
Visual speech area
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Located in angular gyrus
Lesion: alexia
Lateral Ventricle
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Position: located in cerebral
hemispheres
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Four parts
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Central part: lies in parietal lobe
Anterior horn: extends into
frontal lobe
Posterior horn: extend into
occipital lobe
Inferior horn: extend into
temporal lobe
Lateral Ventricle
Transverse MRI scan, at the level of
the anterior horn of the lateral
ventricle.
Lateral Ventricle
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Communication
lateral ventricle →
interventricular foramen →
third ventricle
Basal Nuclei
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Corpus striatum
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－paleostriatum
Lentiform nucleus Globus pallidus
Caudate nucleus
Putamen
Claustrum
Neostriatum
Amygdaloid body
Basal Nuclei
Caudate nucleus
Putamen
Globus pallidus
Claustrum
White Matter
Association fibers
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Run between gyri within the same
hemisphere
Cerebral arcuate fibers
Superior longitudinal fasciculi
Inferior longitudinal fasciculi
Uncinate fasciculus
Cingulum
White Matter
Commissural fibers
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Corpus callosum
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Rostrum
Genu
Trunk
Splenium
Anterior commissure
Fornix and commissure of fornix
White Matter
Projection fibers connect
cortex with lower part of brain and
spinal cord and they include both
ascending and descending fibers
★Internal capsule
 Position: a thick lamina of white
matter lying between caudate
nucleus, thalamus and lentiform
nucleus
Internal Capsule
Caudate nucleus
Lentiform nucleus
Dorsal thalamus
Internal Capsule
Three parts
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Anterior limb of internal capsule
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Genu of internal capsule
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Lies between caudate nucleus and lentiform
nucleus
Containing frontopontine tract and anterior
thalamic radiation
Is angle at which anterior and posterior limbs
meet
Containing corticonuclear tract
Posterior limb of internal capsule
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Lies between thalamus and lentiform nucleus
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Contain corticospinal tract, corticorubral tract,
central thalamic radiation, parieto-occipitotemporo-pontine tract, acoustic radiation and
optic radiation
Anterior thalamic radiation
Head of caudate nucleus
Frontopontine tract
Corticonuclear tract
Corticospinal tract
Dorsal thalamus
Central thalamic
radiation
Lentiform nucleus
Corticorubral tract
Parieto-occipitotemporo-pontine tract
Acoustic radiation
Medial geniculate body
Optic radiation
Lateral geniculate body
Limbic System
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Composition
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Limbic lobe: includes septal area,
cingulated gyrus,
parahippocampal gyrus,
hippocampus, dentate gyrus,
temporal pole, anterior part of
insular lobe and so on
Associated subcortical nuclei:
amygdaloid body, septal nuclei,
hypothalamus, epithalamus,
anterior nucleus group of
thalamus, tegmentum of midbrain
Function: concerned with visceral
activities, olfaction, emotion and
memory, so this system is called
‘visceral brain’