CEREBRUM

CEREBRUM

1.INTRODUCTION :- it is largest part of the brain .

2.SITUATION : it is situated in the cranium occupies the anterior and middle cranial fossae.

3.CEREBRUM is divided by a deep cleft,the longitudinal cerebral fissure, into right and left cerebral hemispheres, each containing one of the lateral ventricles.

• Deep with  in the brain the hemisphers are connected by a mass of white matter(nerve fibers) called the “corpus callosum”.
• The falx cerebri is formed by the dura mater.
• It separates the two hemispheres and penetrates to the depth of the “corpus collasum”
• The superficial part of the cerebrum is composed of nerve cell bodies (or) Grey Matter forming the cerebral cortex.
• The deeper layers consist of nerve fibers or white matter.
• The cerebral cortex shows many infoldings or furrows of varying depth .
• The exposed areas of the folds are gyri or convolutions greatly increase the surface area of the cerebrum

3) PARTS

Divided into lobes with the names of the bones of the cranium.

1.FRONTAL

2.PARIETAL

3.TEMPORAL

4.OCCIPITAL

The boundaries of the lobes are marked by deep sulci.

INFERIOR OF THE CEREBRUM:-

The surface of the cerebral cortex is composed of grey matter (nerve cell bodies )

Within the cerebrum the lobes are connected by mass of nerve fibers, or tracts which make up the white matter of the brain .

The efferent and afferent fibers linking the different parts of the brain and spinal cord as follows.

1.       ASSOCIATION(ACRUATE) TRACTS

2.       COMMISSURAL TRACTS

3.       PROJECTION TRACTS

ASSOCIATION TRACTS:-

It connect different parts of a cerebral hemispheres by extending from one gyrus to another.

COMMISSURAL TRACTS:-

It connects corresponding areas of the two hemisphere by extending from gyrus to another.

It mainly maintains the “corpus callosum”.

PROJECTION TRACTS:-

It connects the cerebral cortex with grey matter of lower parts of the brain and with the spinal cord, example the internal capsule.

THE INTERNAL CAPSULE :-

It is an important projection tract that lies deep within the brain between the basal ganglia (nuclei) and the thalamus.

FUNCTIONS OF THE CEREBRAL CORTEX

Functional  areas of the cerebral cortex.

Motor areas of the cerebral cortex.

Sensory areas of the cerebral cortex.

Association areas.

Other areas of the cerebrum .