Extreme capsule
Encyclopedia
The extreme capsule is a long association fiber pathway of white matter
in the brain
that provides bidirectional communication between such areas as the claustrum
and the insular cortex
, and the inferior frontal gyrus
(Broca’s area) and the middle-posterior portion of the superior temporal gyrus
(Wernicke's area
). Its fibers are near to but can be distinguished by MRI tractography
from adjacent fiber bundles such as the uncinate fasciculus
, the external capsule
, the arcuate fascicle, and the medial, inferior
and superior longitudinal fascicles.
Given its bidirectional connection between the Broca's and Wernicke's speech areas it could have a role in language.
It is most easily visible in a horizontal section, just lateral to the claustrum.
White matter
White matter is one of the two components of the central nervous system and consists mostly of myelinated axons. White matter tissue of the freshly cut brain appears pinkish white to the naked eye because myelin is composed largely of lipid tissue veined with capillaries. Its white color is due to...
in 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,...
that provides bidirectional communication between such areas as the claustrum
Claustrum
The claustrum, which is suspected to be present in all mammals, is a fairly thin vertical curved sheet of subcortical gray matter...
and the insular cortex
Insular cortex
In each hemisphere of the mammalian brain the insular cortex is a portion of the cerebral cortex folded deep within the lateral sulcus between the temporal lobe and the frontal lobe. The cortical area overlying it towards the lateral surface of the brain is the operculum...
, and the inferior frontal gyrus
Inferior frontal gyrus
The inferior frontal gyrus is a gyrus of the frontal lobe . It is labelled gyrus frontalis inferior, its Latin name...
(Broca’s area) and the middle-posterior portion of the superior temporal gyrus
Superior temporal gyrus
The superior temporal gyrus is one of three gyri in the temporal lobe of the human brain, which is located laterally to the head, situated somewhat above the external ear.The superior temporal gyrus is bounded by:* the lateral sulcus above;...
(Wernicke's area
Wernicke's area
Wernicke's area is one of the two parts of the cerebral cortex linked since the late nineteenth century to speech . It is involved in the understanding of written and spoken language...
). Its fibers are near to but can be distinguished by MRI tractography
Tractography
In neuroscience, tractography is a procedure to demonstrate the neural tracts.It uses special techniques of magnetic resonance imaging , and computer-based image analysis.The results are presented in two- and three-dimensional images....
from adjacent fiber bundles such as the uncinate fasciculus
Uncinate fasciculus
The uncinate fasciculus is a white matter tract in the human brain that connects parts of the limbic system such as the hippocampus and amygdala in the temporal lobe with frontal ones such as the orbitofrontal cortex. Its function is unknown though it is affected in several psychiatric conditions...
, the external capsule
External capsule
The external capsule is a series of white matter fiber tracts in the brain. These fibers run between the most lateral segment of the lentiform nucleus and the claustrum....
, the arcuate fascicle, and the medial, inferior
Inferior longitudinal fasciculus
The inferior longitudinal fasciculus connects the temporal lobe and occipital lobe, running along the lateral walls of the inferior and posterior cornua of the lateral ventricle....
and superior longitudinal fascicles.
Given its bidirectional connection between the Broca's and Wernicke's speech areas it could have a role in language.
It is most easily visible in a horizontal section, just lateral to the claustrum.