Commissural fibers
Encyclopedia
The commissural
fibers or transverse fibers connect the two hemispheres of the brain
. They include:
In contrast to commissural fibers, association fibers connect regions within the same hemisphere of the brain. Projection fibers
connect the lobe to other parts of the brain and the spinal cord.
Commissure
A commissure is the place where two things are joined. The term is used especially in the fields of anatomy and biology.In anatomy, commissure refers to a bundle of nerve fibers that cross the midline at their level of origin or entry .* The most common usage of the term refers to the brain's...
fibers or transverse fibers connect the two hemispheres of the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
. They include:
- the transverse fibers of the corpus callosumCorpus callosumThe corpus callosum , also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure. It connects the left and right cerebral hemispheres and facilitates interhemispheric communication...
- the anterior commissureAnterior commissureThe anterior commissure is a bundle of nerve fibers , connecting the two cerebral hemispheres across the midline, and placed in front of the columns of the fornix...
- the posterior commissurePosterior commissureThe posterior commissure is a rounded band of white fibers crossing the middle line on the dorsal aspect of the upper end of the cerebral aqueduct. It is important in the bilateral pupillary light reflex....
- the lyraCommissure of fornixThe lateral portions of the body of the fornix are joined by a thin triangular lamina, named the psalterium . This lamina contains some transverse fibers that connect the two hippocampi across the middle line and constitute the commissure of fornix .The terminal lamina creates the commisure plate...
or hippocampal commissure.
In contrast to commissural fibers, association fibers connect regions within the same hemisphere of the brain. Projection fibers
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.-Efferent:The principal efferent strands are:...
connect the lobe to other parts of the brain and the spinal cord.
