- Projection fibers
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Brain: Projection fibers Latin Fibrae projectionis Gray's subject #189 843 NeuroNames ancil-219 Code TA A14.1.00.018 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:
- (1) the motor tract, occupying the genu and anterior two-thirds of the occipital part of the internal capsule, and consisting of
- (a) the geniculate fibers, which decussate and end in the motor nuclei of the cranial nerves of the opposite side; and
- (b) the cerebrospinal fibers, which are prolonged through the pyramid of the medulla oblongata into the medulla spinalis:
- (2) the corticopontine fibers, ending in the nuclei pontis.
Afferent
The chief afferent fibers are:
- (1) those of the lemniscus which are not interrupted in the thalamus;
- (2) those of the superior cerebellar peduncle which are not interrupted in the red nucleus and thalamus;
- (3) numerous fibers arising within the thalamus, and passing through its stalks to the different parts of the cortex ;
- (4) optic and acoustic fibers, the former passing to the occipital, the latter to the temporal lobe.
External links
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.
Histology: nervous tissue (TA A14, GA 9.849, TH H2.00.06, H3.11) CNS GeneralGrey matter · White matter (Projection fibers · Association fiber · Commissural fiber · Lemniscus · Funiculus · Fasciculus · Decussation · Commissure) · meningesOtherPNS GeneralPosterior (Root, Ganglion, Ramus) · Anterior (Root, Ramus) · rami communicantes (Gray, White) · Autonomic ganglion (Preganglionic nerve fibers · Postganglionic nerve fibers)Myelination: Schwann cell (Neurolemma, Myelin incisure, Myelin sheath gap, Internodal segment)
Satellite glial cellNeurons/
nerve fibersPartsPerikaryon (Axon hillock)
Axon (Axon terminals, Axoplasm, Axolemma, Neurofibril/neurofilament)
Dendrite (Nissl body, Dendritic spine, Apical dendrite/Basal dendrite)TypesGSA · GVA · SSA · SVA
fibers (Ia, Ib or Golgi, II or Aβ, III or Aδ or fast pain, IV or C or slow pain)GSE · GVE · SVE
Upper motor neuron · Lower motor neuron (α motorneuron, γ motorneuron, β motorneuron)Termination SynapseCategories:- Nervous system
- Neuroscience stubs
- (1) the motor tract, occupying the genu and anterior two-thirds of the occipital part of the internal capsule, and consisting of
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