The cerebral cortex has six layers and is only 2-5 mm thick. It contains over 80 billion neurons, mainly of three types: granular, fusiform, and pyramidal. The cortex has folds called gyri separated by sulci. It is divided into four lobes and 52 regions called Brodmann areas defined by cellular structure. There are three main association areas: parieto-occipitotemporal for spatial processing and reading, prefrontal for thoughts and memory, and limbic for emotions and motivation. The ventricles contain cerebrospinal fluid and include the lateral, third, and fourth ventricles.

1. Cerebral cortex &
its components
Dr. Anupam Mittal
MBBS, MD
King George’s Medical University, Lucknow

2. PHYSIOLOGIC ANATOMY OF THE
CEREBRAL CORTEX
• Cerebral cortex is a thin layer of neurons covering the
surface of all the convolutions of the cerebrum.
• Layer - only 2 to 5 millimeters thick
• Contain over 80 billion neurons
• The cortex contains six layers of cells
• This is gray matter surrounding the inner white matter.

5. Structure of the cerebral cortex, showing the following layers:
Layer of fusiform or polymorphic cells
Molecular layer
External granular layer
Layer of pyramidal cells
Internal granular layer
Large pyramidal cell layer

6. Most of the neurons are of three
types:
1) Granular (also called stellate)
• Have short axons, Function mainly as interneurons
• Transmit neural signals only short distances in the cortex
• Some are excitatory (Glutamate)
• Others are inhibitory (Gamma- aminobutyric acid/GABA)
• The sensory areas of the cortex, As well as sensory and
motor
• High degree of intracortical processing

7. Most of the neurons are of three
types:
2) Fusiform
• Spindle shaped cells,
• Located in the deepest layers of cerebral cortex
• Give rise to all output fibers from the cortex
• Their dendrites face towards the cortical surface and
axons are commisural, association or projection type
• Send projection fibres to the Thalamus

8. Most of the neurons are of three
types:
3) Pyramidal (pyramidal shape)
• Found in layer III and V
• Give rise to output fibers from cortex
• Source of Long nerve fibers that go upto Brainstem and
Spinal cord
• Pyramidal neurons in layer III give rise to large
subcortical association fibers

9. Cerebral Cortex
• Surface features of the cortex
• Gyri (singular: gyrus): The rounded convolutions of the
cortex
• Sulci (singular: sulcus): The grooves between the gyri
• There are two hemispheres connected by the
corpus callosum
• Each hemisphere has four lobes

10. Cerebral Cortex

11. Cerebral Cortex

12. Brodmann area
• Originally defined and numbered into 52
regions by the German anatomist Korbinian
Brodmann in the early 1900’s
• the Brodmann areas of the cerebral cortex are
defined by its cytoarchitecture (histological
structure and cellular organization)

17. Functional areas of the human cerebral
cortex

18. 1) The parieto-occipitotemporal association area
2) The prefrontal association area
3) The limbic association area
ASSOCIATION AREAS

19. ASSOCIATION AREAS

20. 1) The parieto-occipitotemporal association area
• Analysis of the Spatial Coordinates of the Body
• Wernicke’s Area Is Important for Language
Comprehension
• The Angular Gyrus Area Is Needed for Initial Processing
of Visual Language (Reading)
ASSOCIATION AREAS

21. Wernicke’s Area Is Important for Language Comprehension
lies behind the primary auditory cortex in the posterior part of the
superior gyrus of the temporal lobe

22. 2) The prefrontal association area
• in close association with the motor cortex to plan complex
patterns and sequences of motor movements
• is also essential to carrying out “thought” processes
(elaboration of thoughts)
• store on a short- term basis “working memories”
• used to combine new thoughts while they are entering the brain
• Broca’s Area Provides the Neural Circuitry for Word Formation.
ASSOCIATION AREAS

23. Broca’s Area
• Located partly in the posterior
lateral prefrontal cortex and
partly in the premotor area
• Plans and motor patterns for
expressing individual words or
even short phrases are
initiated and execute
• Also works in close
association with the Wernicke

24. 3) The limbic association area
• is found in the anterior pole of the temporal lobe and in the
cingulate gyrus lying deep
• It is concerned primarily with behavior, emotions, and
motivation
• Provides most of the emotional drives
• for activating other areas of the brain
• provides motivational drive for the process of learning itself.
ASSOCIATION AREAS

25. A GENERAL INTERPRETATIVE AREA
• The somatic, visual, and auditory association areas
all meet one another in the posterior part of the
superior temporal lobe

26. The Ventricular
System
• Four ventricles filled with CSF found
in brain
• The two lateral ventricles in the
cerebrum
• The third ventricle in the
diencephalon of the forebrain
between the right and left
thalamus
• The fourth ventricle located at the
back of the pons and upper half of
the medulla oblongata

27. The Ventricular System and Brain
Function