The Telencephalon SHANDONG UNIVERSITY Liu Zhiyu. General Appearance of Cerebrum The telencephalon...
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Transcript of The Telencephalon SHANDONG UNIVERSITY Liu Zhiyu. General Appearance of Cerebrum The telencephalon...
The Telencephalon
SHANDONG UNIVERSITY
Liu Zhiyu
General Appearance of Cerebrum
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 SulciThree principal sulci Central sulcus Lateral sulcus Parietooccipital sulcus
Central sulcus
Lateral sulcus
Parietooccipital sulcus
Lobes of Cerebral Hemisphere
Five lobes Frontal lobe Parietal lobe Temporal lobe Occipital lobe Insular lobe
Frontal lobe Parietal lobe
Occipital lobe
Temporal lobe
Insular lobe
Sulci and gyri of frontal lobe
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 sulcus
Precentral gyrus
Superior frontal sulcus
Inferior frontal sulcus
Superior, middleand inferioe frontal gyri
Sulci and Gyri of Parietal Lobe
Postcentral sulcus Postcentral gyrus Intraparietal sulcus Superior parietal lobule Inferior parietal lobule Supramarginal gyrus Angular gyrus
Sulci and Gyri of Parietal Lobe
Postcentral sulcus
Postcentral gyrus
Superior parietal lobule
Supramarginal gyrus
Angular gyrus
Intraparietal sulcus
Sulci and Gyri of Temporal Lobe
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
Inferior temporal sulcus Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
Transverse temporal gyri
Sulci and Gyri of Temporal Lobe
Sulci and gyri of Superolateral surface
Precentral sulcus
Precentral gyrus
Superior frontal sulcus
Inferior frontal sulcus
Superior,middleand inferior frontal gyri
Postcentral sulcus
Postcentral gyrus
Superior parietal lobule
Supramarginal gyrus
Angular gyrus
Superior temporal sulcus
Inferior temporal sulcus Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
Intraparietal sulcus
Sulci and Gyri of Medial Surface
Corpus callosum Callosal sulcus Cingulate gyrus Cingulate sulcus Marginal ramus Paracentral lobule Calcarine sulcus Cuneus Lingual gyrus
Sulci and Gyri of Medial Surface
Corpus callosum Callosal sulcus
cingulate gyrus
Cingulate sulcus
Marginal ramus
Paracentral lobule
Calcarine sulcus
Cuneus
Parietooccipital sulcus
Lingual gyrus
Sulci and Gyri of Inferior Surface
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
Ant. Perforated substance
Collateral sulcus
Occipitotemporal sulcus
Medial occipitotemporal gyrus
Parahippocampalgyrus
Uncus
Lateral occipitotemporal gyrus
Hippocampus
Dentate gyrus
Hippocampal formation
Sulci and Gyri of Inferior Surface
Histology of Cerebral Cortex 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 an
d anterior portion of paracentral lobule
First Somatic Motor Area
Characters Representation is inverted, but he
ad and face are upright A body part is represented by a c
ortical 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 p
osterior portion of paracentral lobule
First Somatic Sensory Area
Characters Sensory representation, like m
otor area, is crossed and inverted
Receiving fibers from ventral posterior nucleus
Interpret sensation from opposite side of body
First Somatic Sensory Area
Visual Area
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
Located in transverse temporal gyri
Receive auditory information from both ears
Vestibular area: located in front of superior temporal gyrus
Olfactory area: located near the uncus
Taste area: located at frontal operculum
Language Area
Motor speech area Located in posterior portion of inferior fr
ontal gyrus Damage: motor aphasia
Writing area Located in posterior portion of middle fr
ontal gyrus Damage: agraphia
Auditory speech area Located in posterior portion of superior t
emporal gyrus Lesion: sensory aphasia
Visual speech area Located in angular gyrus Lesion: alexia
It is dominant in left hemisphere in right-handed person
Position: located in cerebral hemispheres
Four parts 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
Lateral Ventricle
Transverse MRI scan, at the level of the anterior horn of the lateral ventricle.
Lateral Ventricle
Communication
lateral ventricle → interventricular foramen → third ventricle
Basal Nuclei
Corpus striatum Lentiform nucleus Caudate nucleus
Claustrum
Amygdaloid body
PutamenNeostriatum
- paleostriatumGlobus pallidus
Basal Nuclei
Caudate nucleus
Putamen
Globus pallidus
Claustrum
White Matter
Association fibers Run between gyri within the same he
misphere Cerebral arcuate fibers Superior longitudinal fasciculi Inferior longitudinal fasciculi Uncinate fasciculus Cingulum
White Matter
Commissural fibers Corpus callosum
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
Lentiform nucleus
Caudate nucleus
Dorsal thalamus
Internal CapsuleThree parts Anterior limb of internal capsule
Lies between caudate nucleus and lentiform nucleus
Containing frontopontine tract and anterior thalamic radiation
Genu of internal capsule Is angle at which anterior and posterior limbs
meet Containing corticonuclear tract
Posterior limb of internal capsule Lies between thalamus and lentiform nucleus Contain corticospinal tract, corticorubral tract,
central thalamic radiation, parieto-occipito-temporo-pontine tract, acoustic radiation and optic radiation
Anterior thalamic radiation
Frontopontine tract
Lentiform nucleus
Corticorubral tract
Parieto-occipito-temporo-pontine tract
Acoustic radiation
Optic radiation
Head of caudate nucleus
Corticonuclear tract
Corticospinal tract
Dorsal thalamus
Central thalamic radiation
Medial geniculate body
Lateral geniculate body
Limbic System
Composition 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’