Long association fibers
Fibrae longae associationis
- Latin synonym: Fibrae associationis longae
- Related terms: Long association fibres
Definition
The long association fibers include the following:
- uncinate fasciculus;
- cingulum;
- superior longitudinal fasciculus;
- inferior longitudinal fasciculus;
- perpendicular fasciculus;
- occipitofrontal fasciculus;
- fornix.
References
The long association fibres are intrahemispheric cortico-cortical white-matter fibres that connect widely separated areas of the cerebral cortex within the same hemisphere, frequently linking different cerebral lobes.
Unlike short association fibres (arcuate or U-fibres), which mainly connect adjacent or nearby gyri, long association fibres extend over considerably greater distances.
Major long association fibre systems include the superior longitudinal fasciculus, arcuate fasciculus, inferior longitudinal fasciculus, inferior occipitofrontal fasciculus, uncinate fasciculus and cingulum.
Important distinctions
The association fibres should be distinguished from commissural fibres, which connect cortical regions of the two cerebral hemispheres, and projection fibres, which connect the cerebral cortex with subcortical structures, brainstem and spinal cord.