A nerve tract is a bundle of nerve fibers connecting nuclei of the central nervous system.
The central nervous system is the part of the nervous system consisting of the brain and spinal cord.
THE SPINAL CORD & SPINAL TRACTS; PART 1 by Professor Fink by professorfink
In the peripheral nervous system this is known as a nerve.
Olfactory Pathway - Nerve and Tracts by MEDSimplified
The main nerve tracts in the central nervous system are of three types: association fibers, commissural fibers, and projection fibers.
The projection fibers consist of efferent and afferent fibers uniting the cortex with the lower parts of the brain and with the spinal cord.
Association fibers are axons that connect cortical areas within the same cerebral hemisphere.
A tract may also be referred to as a commissure, fasciculus or decussation.
A commissure is the location at which two objects abut or are joined.
Decussation is used in biological contexts to describe a crossing.
A commissure connects the two cerebral hemispheres at the same levels.
The vertebrate cerebrum is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure.
Examples are the posterior commissure and the corpus callosum.
The corpus callosum, also callosal commissure, is a wide, thick, nerve tract consisting of a flat bundle of commissural fibers, beneath the cerebral cortex in the brain.
The posterior commissure is a rounded band of white fibers crossing the middle line on the dorsal aspect of the rostral end of the cerebral aqueduct.
A decussation is a connection made by fibres that cross at different levels, such as the sensory decussation.
The sensory decussation or decussation of the lemniscus is a decussation or crossover of axons from the gracile nucleus and cuneate nucleus, which are responsible for fine touch, proprioception and two-point discrimination of the body.
Examples of a fascicle are the subthalamic fasciculus and the lenticular fasciculus.