Pyramidal tract is a collection of axons that travel between the cerebral cortex of the brain and the spinal cord.
Pyramidal tract contains
Two separate tracts in the spinal cord:
lateral corticospinal tract
anterior corticospinal tract.
One tract in the brain stem
. (carries signals that control motor neurons located in cranial nerve brain nuclei)
The neurons of the pyramidal tracts are called pyramidal neurons
When the pyramidal tract passes the medulla, it forms a dense bundle of nerve fibres that is shaped like a pyramid.
The course and nomenclature
starts in the precentral gyrus and ends in the spine
Once the axons leave the pyramidal cells, they enter the white matter just below and form the
The corona radiata dives into the basal ganglia. At this point called the
Sensory information travels up the tract from the thalamus to the cortex
Motor information travels down to the spine.
At the level where the midbrain begins, the axons are called the
At the level of pons, many of the axons from cortex (the "corticopontine" fibers) get off and synapse with pontine nuclei.
The remaining corticospinal axons continue down.
In the medulla, the fibers are called the
because they look like pyramids
At the very caudal-most end of the medulla, the fibers in the pyramids cross. (decussation of the pyramidal tract)
The cerebrum controls the opposite side of the body
the corticospinal fibers are called the lateral corticospinal tract.
In the spinal cord they synapse either on interneurons (most common) or directly on the a-motor neurons. They preferentially
innervate the limbs and distal muscles.
The internal capsule is very vulnerable to strokes (ischaemia) leading to hemiplegia.
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