Internal Capsule
Definition
Is an important area in the cerebrum
Consists of projection fibres
Situation
It lies deep within the brain
Between the basal ganglia and the thalamus
Structure
Formed of fibres that pass from and to the cerebral cortex
Motor fibres within the internal capsule form the pyramidal tracts (corticospinal tracts)
The pyramidal tracts decussate at the medulla oblongata
Function
Passing impulses from and to the cerebral cortex
Clinical application
This part of the brain is usually damaged in old age due to cutting off of blood supply causing hemiplegia
The symptoms of hemiplegia are called pyramidal symptoms
Extra pyramidal symptoms mean symptoms caused by damage to basal ganglia and substantia nigra means the internal capsule - containing pyramidal tract is not involved.
Coronal Section of the Brain
