Association fiber

Association fibers are axons that connect cortical areas within the same cerebral hemisphere.[1]

In human neuroanatomy, axons within the brain, called fibers, can be categorized on the basis of their course and connection into association fibers, projection fibers, and commissural fibers.[1]

The association fibers unite different parts of the same cerebral hemisphere, and are of two kinds: (1) those connecting adjacent gyri, short association fibers; (2) those passing between more distant parts, long association fibers.

Association fiber
Gray751
Diagram showing principal systems of association fibers in the cerebrum.
Gray752
Dissection of cerebral cortex and brainstem showing association fibers and insular cortex after removal of its superficial grey matter
Details
Identifiers
LatinFibrae associationis telencephali
TAA14.1.00.016
A14.1.09.553
FMA75241
Anatomical terms of neuroanatomy

Short association fibers

Many of the short association fibers (also called arcuate or "U"-fibers) lie immediately beneath the gray substance of the cortex of the hemispheres, and connect together adjacent gyri.[2] Some pass from one wall of the sulcus to the other.[2]

Long association fibers

The long association fibers connect the more widely separated gyri and are grouped into bundles.[2] They include the following:

Name From To
uncinate fasciculus frontal lobe temporal lobe
cingulum cingulate gyrus entorhinal cortex
superior longitudinal fasciculus frontal lobe occipital lobe
inferior longitudinal fasciculus occipital lobe temporal lobe
vertical occipital fasciculus inferior parietal lobule fusiform gyrus
occipitofrontal fasciculus occipital lobe frontal lobe
Arcuate fasciculus frontal lobe temporal lobe

Diffusion tensor imaging is a non-invasive method to study the course of association fibers.

See also

References

  1. ^ a b Standring, Susan (2005). Gray's Anatomy: The Anatomical Basis of Clinical Practice (39th ed.). Churchill Livingstone. p. 411. ISBN 9780443071683. The nerve fibres which make up the white matter of the cerebral hemispheres are categorized on the basis of their course and connections. They are association fibres, which link different cortical areas in the same hemisphere; commissural fibres, which link corresponding cortical areas in the two hemispheres; or projection fibres, which connect the cerebral cortex with the corpus striatum, diencephalon, brain stem and the spinal cord.
  2. ^ a b c Standring, Susan (2005). Gray's Anatomy: The Anatomical Basis of Clinical Practice (39th ed.). Churchill Livingstone. p. 411. ISBN 9780443071683. Association fibres may be either short association (arcuate or 'U') fibres, which link adjacent gyri, or long association fibres, which connect more widely separated gyri. Short association fibres may be entirely intracortical. Many pass subcortically betweena adjacent gyri, some merely pass from one wall of a sulcus to the other. Long association fibres are grouped into bunbles, ...

External links

Ana Karen Allende

Ana Karen Allende is a Mexican artisan from the Mexico City borough of Coyoacán, who specializes in creating rag dolls and soft fabric animals. The tradition of making rag dolls in Mexico extends back to the pre-Hispanic period with the making of rag dolls reaching its peak in the 19th century. Allende’s first doll was made when her sister was about to turn fifteen. For quinceañera celebrations in Xochimilco, it is customary to give the girl her “last doll” as a means of marking her transition from child to adult. Allende decided to make this doll herself, using sewing skills taught to her by her grandmother. Soon after, she began to make dolls for her friends and family, and the attention they received prompted her to think of selling them.

Allende started her own small business called Retacitos (Scraps) in 2002 involving other members of her family, such as her at that time husband Sinhúe Lucas, along with contracting various single mothers in her area to work. She sells directly to the public only on Saturdays at the Art Bazaar in the San Ángel neighborhood. Her other sales are mainly to stores and museums. She receives a number of custom orders including making dolls that look like famous people such as Frida Kahlo and even those that look like the purchaser. Allende states that her goal is to revive the craft of doll making but in a more modern form. She generally sticks to forms familiar to Mexican concepts of cultural identity such as lucha libre wrestlers, angels, traditional rag dolls, horses, mermaids, rabbits, etc. She has been recognized as an authentic Mexican craftswoman since 2010 by the government of Mexico City, her work has been exhibited in various museums and cultural events and has won the 3rd place at the VI Bienal Internacional de Arte Textil Contemporáneo WTA (2012) and the 1st place in the toys category at the Gran Premio de Arte Popular of FONART (2006) among other distinctions.

Arcuate fasciculus

The arcuate fasciculus (Latin: curved bundle) is a bundle of axons that connects Broca's area and Wernicke's area. It is an association fiber tract connecting caudal temporal cortex and inferior frontal lobe.

Extreme capsule

The extreme capsule (Latin: capsula extrema) 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.

Fiber optic filter

Fiber optic filter is an optical fiber instrument used for wavelength selection, which can select desired wavelengths to pass and reject the others. It is Widely used in DWDM systems dynamic wavelength selection, DWDM signal separation, optical performance monitoring, field tunable optical noise filtering and optical amplifier noise suppression, etc. Optical multiplexers (couplers) makes different wavelength coupling into an optical fiber and different wavelength carries different information. At the receiving end, if you want to separate desired wavelengths from optical fiber, it is necessary to use optical filter.

Fiber optic splitter

A fiber optic splitter, also known as a beam splitter, is based on a quartz substrate of an integrated waveguide optical power distribution device, similar to a coaxial cable transmission system. The optical network system uses an optical signal coupled to the branch distribution. The fiber optic splitter is one of the most important passive devices in the optical fiber link. It is an optical fiber tandem device with many input and output terminals, especially applicable to a passive optical network (EPON, GPON, BPON, FTTX, FTTH etc.) to connect the MDF and the terminal equipment and to branch the optical signal.

Fiber to the telecom enclosure

Fiber to the telecom enclosure (FTTTE), also sometimes called fiber to the zone (FTTZ), or fibre to the cabinet (FTTC) in the UK is a standards-compliant structured cabling system architecture that extends the optical fiber backbone network from the equipment room, through the telecom room, and directly to a telecommunications enclosure (TE) installed in a common space to serve a number of users in a work area.

Ganglion

A ganglion is a nerve cell cluster or a group of nerve cell bodies located in the autonomic nervous system and sensory system. Ganglia house the cell bodies of afferent nerves (input nerve fibers) and efferent nerves (output/motor nerve fibers), or axons.

A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies.

Superior longitudinal fasciculus

The superior longitudinal fasciculus (SLF) is an association fiber tract that is composed of three separate components. It is present in both hemispheres and can be found lateral to the centrum ovale and connects the frontal, occipital, parietal, and temporal lobes. These bundles of axon tracts pass from the frontal lobe through the operculum to the posterior end of the lateral sulcus where they either radiate to and synapse on neurons in the occipital lobe or turn downward and forward around the putamen and then radiate to and synapse on neurons in anterior portions of the temporal lobe.The SLF is composed of three distinct components SLF I, SLF II, and SLF III.

Vereinigte Glanzstoff-Fabriken

Vereinigte Glanzstoff-Fabriken (VGF, United Rayon Factories) was a German manufacturer of artificial fiber founded in 1899 that became one of the leading European producers of rayon.

During the first thirty years VGF cooperated closely with the British manufacturer Courtaulds and other companies to share technology and maintain prices by avoiding competition. It merged with the Dutch firm Enka in 1929 under the holding company Algemene Kunstzijde Unie (AKU), but the two retained their legal identities.

AKU made significant investments in rayon production in the United States.

The company suffered government interference in Nazi Germany (1933–45) and lost competitive strength during World War II, but partly recovered after the war with American assistance.

In 1969 AKU merged with the Dutch manufacturer KZO to form AKZO, now part of AkzoNobel. Successor companies formed during various divestitures, mergers and acquisitions continue to be active in various related industries.

CNS
PNS
Neurons/
nerve fibers
Termination
Association fibers in the human brain
Association fibers

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.