This is the second lecture in neuroanatomy presented and taught by Ahmed Eljack to second level medical students at Alneelain University. This lecture discussed the divisions and landmarks of the cerebrum, important white matter bundles of the cerebrum and their functions, and the meninges.

1. Cerebrum (1)
Overview and Cerebral Cortex
By: Ahmed A. E. Eljack

2. Objectives:
2
By the end of this session you should be able
to:
● Describe the divisions and landmarks of the
cerebrum.
● List the important white matter bundles of
the cerebrum and their functions.
● List the meninges that cover the cerebrum.

3. Divisions and Landmarks of the
Cerebrum
3

4. Sulci and Gyri:
● Sulci are the grooves that are found in the
cerebrum and cerebellum separating the
gyri. Fissures are deep sulci.
● Gyri are the ridges which are found in the
cerebrum and cerebellum and separated by
sulci.
4

5. “If it were possible to unfold the cerebral cortex
from one hemisphere (which can be
done in digital representations of the cerebral
hemisphere), the surface area of the
resulting, flattened cerebral cortex would be
roughly approximated by the crust of a
13-inch pizza (thin crust, New York style, of
course, given the thinness of the cortex).”
Leonard E. White, Ph.D
5

6. Important Sulci in the Cerebrum:
● Longitudinal fissure: separates the two
hemispheres.
● Central sulcus (fissure of Rolando): separates
the frontal lobe from the parietal lobe.
● Lateral fissure (Sylvian fissure): separates the
frontal and parietal lobes from the temporal
lobe. 6

7. 7
Eljack’s Lecture Notes in Neuroscience. Fig. 7-1
©2015 all rights reserved

8. 8
Important Sulci in the Cerebrum:
● Cingulate sulcus: Lies superior to the
cingulate gyrus.
● Parietal-occipital sulcus: separates the
parietal lobe from the occipital lobe.
● Calcarine sulcus: separates between the
cuneus and the lingual gyri.

9. 9
Eljack’s Lecture Notes in Neuroscience. Fig. 7-2
©2015 all rights reserved

10. Lobes of the Cerebrum:
10
Cerebrum contains the following lobes in
each hemisphere:
● Frontal lobe.
● Parietal lobe.
● Temporal lobe.
● Occipital lobe.
● Insula.

11. 11
Eljack’s Lecture Notes in Neuroscience. Fig. 7-3
©2015 all rights reserved

12. 12
Eljack’s Lecture Notes in Neuroscience. Fig. 7-4
©2015 all rights reserved

13. Important Cerebral Gyri:
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● Precentral gyrus: lies just anterior to the
central sulcus. It’s the primary motor cortex.
● Postcentral gyrus: lies just posterior to the
central sulcus. It’s the primary somatosensory
cortex.

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Important Cerebral Gyri:
● Lingual and cuneus gyri: lie inferior and
superior to the calcarine sulcus, respectively.
Constitute the primary visual cortex.
● Superior temporal gyrus: contains the
auditory cortex.

15. 15
Important Cerebral Gyri:
● Cingulate gyrus and insula: important parts
of the limbic formation.
● Hippocampus and parahippocampus:
important parts of the limbic formation.
● Supramarginal and angular gyri: important in
language perception.

16. 16
Brodmann's Classification
● This classification depends on the
cytoarchitecture (histology of the different
neurons) of the cerebrum.
● It uses numbers to label areas Brodmann
believed to have the same cytoarchitecture
(more than 50 areas).

17. 17
Eljack’s Lecture Notes in Neuroscience. Fig. 7-5
©2015 all rights reserved

18. 18
Eljack’s Lecture Notes in Neuroscience. Fig. 7-6
©2015 all rights reserved

19. 19
White Matter of the Cerebrum

20. Main Cerebral White Matter Fiber Bundles:
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● Corpus callosum: connects most of the two
hemispheres (commissural fibers).
● Anterior commissure: connect the ventral
parts of the cerebrum (commissural fibers).
● Fornix: connects the hippocampus with the
hypothalamus.

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● Posterior commissure: connects the
pretectal nuclei (consensual pupillary light
reflex).
● Internal capsule: afferent and efferent
projection fibers.
Main Cerebral White Matter Fiber Bundles:

22. 22
Meninges of the Cerebrum:

23. Types of meninges:
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There are three meninges surrounding the CNS:
1. Dura mater.
2. Arachnoid mater.
3. Pia mater.

24. Dura Mater:
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● It’s the outermost part of the meninges.
● Composed of two layers: endosteal and
meningeal layers.
● It’s continuous with the dura of the spinal
cord.

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Dura Mater:
● In the cerebrum there are three folds of the
dura:
○ Falx cerebri: between the cerebral
hemispheres.
○ Tentorium cerebelli: covering the posterior
cranial fossa over the cerebellum.
○ diaphragma sellae: over sella turcica.

26. 26
Snell, R.S. Clinical Neuroanatomy. (7th ed.). Philadelphia:
Lippincott Williams & Wilkins; 2010. Fig. 15-3

27. Arachnoid Mater:
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● It’s a delicate part of the meninges between
the dura and the pia. They bridge over the
sulci
● In some areas, they project into the venous
sinuses (arachnoid villi).
● The CSF and the cerebral arteries and veins
run in the subarachnoid space.

28. Pia Mater:
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● It’s a thin vascular membrane covered by
flattened mesothelial cells.
● It closely invests the brain. It descend into
sulci.

29. Further Readings:
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● Sadler, T.W. Langman's Medical Embryology.
(12th ed.). Philadelphia: Lippincott Williams &
Wilkins; 2012.
● Mescher, A.L. Junqueira's Basic Histology Text
and Atlas. (13th ed.). : McGraw-Hill; 2013.

30. 30
● Sinnatamby, C.S. Last's Anatomy Regional and
Applied. (12th ed.). : Churchill Livingstone;
2011.
● Snell, R.S. Clinical Neuroanatomy. (7th ed.).
Philadelphia: Lippincott Williams & Wilkins;
2010.
Further Readings:

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● Eljack, A. A. E. Eljack’s Lecture Notes in
Neuroscience. Khartoum; 2015.
● Siegel, A, Sapru, H.N. Essential Neuroscience.
(3rd ed.). Philadelphia: Lippincott Williams &
Wilkins; 2015.
Further Readings:

32. 32
Further Readings:
● Waxman, S.G. Clinical Neuroanatomy. (26th
ed.). : McGraw-Hill; 2010.
● Medical Neuroscience MOOC by Duke
University | Coursera.