1. SHANDONG UNIVERSITY Liu Zhiyu
The Telencephalon
SHANDONG UNIVERSITY
Liu Zhiyu

2. 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

3. Main Sulci Three principal sulci Central sulcus Lateral sulcus
Parietooccipital sulcus
Central sulcus
Parietooccipital sulcus
Lateral sulcus

4. Lobes of Cerebral Hemisphere
Five lobes
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Insular lobe
Insular lobe
Parietal lobe
Frontal lobe
Occipital lobe
Temporal lobe

5. 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

6. Sulci and gyri of frontal lobe
Precentral gyrus
Precentral sulcus
Superior frontal sulcus
Inferior frontal sulcus
Superior, middle
and inferioe frontal
gyri

7. Sulci and Gyri of Parietal Lobe
Postcentral sulcus
Postcentral gyrus
Intraparietal sulcus
Superior parietal lobule
Inferior parietal lobule
Supramarginal gyrus
Angular gyrus

8. Sulci and Gyri of Parietal Lobe
Postcentral gyrus
Postcentral sulcus
Superior parietal lobule
Intraparietal sulcus
Supramarginal gyrus
Angular gyrus

9. Sulci and Gyri of Temporal Lobe
Superior temporal sulcus
Inferior temporal sulcus
Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
Transverse temporal gyri

10. Sulci and Gyri of Temporal Lobe
Superior temporal sulcus
Superior temporal gyrus
Inferior temporal sulcus
Middle temporal gyrus
Inferior temporal gyrus

11. Sulci and Gyri of Temporal Lobe
Transverse temporal gyri

12. Sulci and gyri of Superolateral surface
Precentral gyrus
Precentral sulcus
Postcentral gyrus
Superior frontal sulcus
Postcentral sulcus
Intraparietal sulcus
Inferior frontal sulcus
Superior parietal lobule
Superior,
middle
and inferior
frontal
gyri
Supramarginal gyrus
Angular gyrus
Superior temporal sulcus
Superior temporal gyrus
Inferior temporal sulcus
Middle temporal gyrus
Inferior temporal gyrus

13. Sulci and Gyri of Medial Surface
Corpus callosum
Callosal sulcus
Cingulate gyrus
Cingulate sulcus
Marginal ramus
Paracentral lobule
Calcarine sulcus
Cuneus
Lingual gyrus

14. Sulci and Gyri of Medial Surface
Corpus callosum
Callosal sulcus
Paracentral lobule
cingulate gyrus
Marginal ramus
Cingulate sulcus
Parietooccipital
sulcus
Cuneus
Calcarine sulcus
Lingual gyrus

15. 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

16. 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

17. Sulci and Gyri of Inferior Surface
Hippocampus
Hippocampal
formation
Dentate gyrus

18. Histology of Cerebral Cortex
Archicortex (hippocampal formation)
Paleocortex (rhinencephalon)
Neocortex (most of cerebral cortex)
3 cell layers
6 cell layers

19. Functional Location of Cerebral Cortex

20. First Somatic Motor Area
Position:
Located in precentral gyrus and anterior portion of paracentral lobule

21. First Somatic Motor Area
Characters
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

22. First Somatic Motor Area

23. First Somatic Motor Area

24. First Somatic Sensory Area
Position:
Lies in postcentral gyrus and posterior portion of paracentral lobule

25. First Somatic Sensory Area
Characters
Sensory representation, like motor area, is crossed and inverted
Receiving fibers from ventral posterior nucleus
Interpret sensation from opposite side of body

26. First Somatic Sensory Area

27. 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

28. Auditory Area Located in transverse temporal gyri
Receive auditory information from both ears

29. Vestibular area: located in front of superior temporal gyrus
Olfactory area: located near the uncus
Taste area: located at frontal operculum

30. Language Area It is dominant in left hemisphere in right-handed person
Motor speech area
Located in posterior portion of inferior frontal gyrus
Damage: motor aphasia
Writing area
Located in posterior portion of middle frontal gyrus
Damage: agraphia
Auditory speech area
Located in posterior portion of superior temporal gyrus
Lesion: sensory aphasia
Visual speech area
Located in angular gyrus
Lesion: alexia

31. Lateral Ventricle 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

32. Lateral Ventricle
Transverse MRI scan, at the level of the anterior horn of the lateral ventricle.

33. Lateral Ventricle Communication
lateral ventricle → interventricular foramen → third ventricle

34. Basal Nuclei Corpus striatum Amygdaloid body Lentiform nucleus
Caudate nucleus Claustrum
Amygdaloid body
Globus pallidus
－paleostriatum
Putamen
Neostriatum

35. Basal Nuclei
Caudate nucleus
Putamen
Globus pallidus
Claustrum

36. White Matter Association fibers
Run between gyri within the same hemisphere
Cerebral arcuate fibers
Superior longitudinal fasciculi
Inferior longitudinal fasciculi
Uncinate fasciculus
Cingulum

37. White Matter Commissural fibers Corpus callosum Anterior commissure
Rostrum
Genu
Trunk
Splenium
Anterior commissure
Fornix and commissure of fornix

38. 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

39. Internal Capsule
Caudate nucleus
Lentiform nucleus
Dorsal thalamus

40. Internal Capsule Three 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

41. Anterior thalamic radiation
Head of caudate nucleus
Frontopontine tract
Corticonuclear tract
Lentiform nucleus
Corticorubral tract
Corticospinal tract
Parieto-occipito-
temporo-pontine tract
Dorsal thalamus
Central thalamic
radiation
Acoustic radiation
Medial geniculate body
Optic radiation
Lateral geniculate body

42. 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’