Human Anatomy - Kotsan I. Ya. 2009

Pathways of the Brain and Spinal Cord
Projection Pathways

Projection pathways provide bidirectional communication between the Cerebral Cortex AND the nuclei of the Brainstem (short projection pathways) as well as the Spinal Cord (long projection pathways).

Depending on the direction of Nerve Impulse Conduction, projection pathways are classified into ascending (afferent, sensory, centripetal) pathways, which transmit nerve impulses from the periphery to the cerebral cortex, and descending (efferent, motor, centrifugal) pathways, which transmit nerve impulses from the cerebral cortex to the periphery.

Both ascending and descending projection pathways serve as Components of the reflex arc. Contact between these components is established within the cerebral cortex, specifically in the associative cortical areas. Functionally, therefore, they form an integrated whole—a closed chain of sequentially connected Neurons. However, due to the extreme structural complexity of reflex arcs, their components (afferent and efferent) are traditionally examined separately as afferent (ascending) and efferent (descending) projection pathways.



Last update: 08/08/2026

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