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Cortico-olivary Fibers
The cortico-olivary fibers are axons of neurons projecting from the primary motor cortex, premotor cortex, and somatosensory cortex bilaterally to both inferior olivary nuclei as part of the cortico-olivocerebellar pathway. They follows the same course as the corticopontine fibers. The inferior olivary nuclei subsequently project to the contralateral (cerebro)cerebellum via the olivocerebellar fibers. This pathway constitutes one of the three main afferent pathways of the cerebellum (besides the spinocerebellar tract The spinocerebellar tracts are nerve tracts originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum. The two main tracts are the dorsal spinocerebellar tract, and the ventral spinocerebellar tract. Both of ..., and vestibulocerebellar tract). References {{neuroanatomy-stub Central nervous system pathways Cerebral white matter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Motor Cortex
The primary motor cortex ( Brodmann area 4) is a brain region that in humans is located in the dorsal portion of the frontal lobe. It is the primary region of the motor system and works in association with other motor areas including premotor cortex, the supplementary motor area, posterior parietal cortex, and several subcortical brain regions, to plan and execute voluntary movements. Primary motor cortex is defined anatomically as the region of cortex that contains large neurons known as Betz cells, which, along with other cortical neurons, send long axons down the spinal cord to synapse onto the interneuron circuitry of the spinal cord and also directly onto the alpha motor neurons in the spinal cord which connect to the muscles. At the primary motor cortex, motor representation is orderly arranged (in an inverted fashion) from the toe (at the top of the cerebral hemisphere) to mouth (at the bottom) along a fold in the cortex called the central sulcus. However, some body p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premotor Cortex
The premotor cortex is an area of the motor cortex lying within the frontal lobe of the brain just anterior to the primary motor cortex. It occupies part of Brodmann's area 6. It has been studied mainly in primates, including monkeys and humans. The functions of the premotor cortex are diverse and not fully understood. It projects directly to the spinal cord and therefore may play a role in the direct control of behavior, with a relative emphasis on the trunk muscles of the body. It may also play a role in planning movement, in the spatial guidance of movement, in the sensory guidance of movement, in understanding the actions of others, and in using abstract rules to perform specific tasks. Different subregions of the premotor cortex have different properties and presumably emphasize different functions. Nerve signals generated in the premotor cortex cause much more complex patterns of movement than the discrete patterns generated in the primary motor cortex. Structure The pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatosensory Cortex
The somatosensory system, or somatic sensory system is a subset of the sensory nervous system. The main functions of the somatosensory system are the perception of external stimuli, the perception of internal stimuli, and the regulation of body position and balance (proprioception). It is believed to act as a pathway between the different sensory modalities within the body. As of 2024 debate continued on the underlying mechanisms, correctness and validity of the somatosensory system model, and whether it impacts emotions in the body. The somatosensory system has been thought of as having two subdivisions; *one for the detection of mechanosensory information related to touch. Mechanosensory information includes that of light touch, vibration, pressure and tension in the skin. Much of this information belongs to the sense of touch which is a general somatic sense in contrast to the special senses of sight, smell, taste, hearing, and balance. * one for the nociception detect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Olivary Nucleus
The inferior olivary nucleus (ION) is a structure found in the medulla oblongata underneath the superior olivary nucleus.Gado, Thomas A. Woolsey; Joseph Hanaway; Mokhtar H. (2003). The brain atlas a visual guide to the human central nervous system (2nd ed.). Hoboken, NJ: Wiley. p. 206. . In vertebrates, the ION is known to coordinate signals from the spinal cord to the cerebellum to regulate motor coordination and learning.Schweighofer N, Lang EJ, Kawato M. Role of the olivo-cerebellar complex in motor learning and control. ''Frontiers in Neural Circuits''. 2013;7:94. . These connections have been shown to be tightly associated, as degeneration of either the cerebellum or the ION results in degeneration of the other. Neurons of the ION are glutamatergic and receive inhibitory input via GABA receptors. There are two distinct GABAα receptor populations that are spatially organized within each neuron present in the ION. The GABAα receptor make-up varies based on where the rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticopontine Fibers
Corticopontine fibers are projections from layer V of the cerebral cortex to the pontine nuclei of the ventral pons. They represent the first link in a cortico-cerebello-cortical pathway mediating neocerebellar control of the motor cortex. The pathway is especially important for voluntary movements. Depending upon the lobe of origin, they can be classified as frontopontine fibers, parietopontine fibers, temporopontine fibers or occipitopontine fibers. Fibers from the frontal lobe and the parietal lobe are more numerous. Anatomy Origin All corticopontine fibers arise from pyramidal neurons in layer V of the cerebral cortex. They include fibers of the premotor, somatosensory, extrastriate, posterior parietal, and cingulate cortices; there are also a few fibers originating from the prefrontal, temporal, and striate cortex. The corticopontine system contains a number of fibers from different areas of the cortex, and are far more numerous in total than the corticos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebrocerebellum
The anatomy of the cerebellum can be viewed at three levels. At the level of gross anatomy, the cerebellum consists of a tightly folded and crumpled layer of cortex, with white matter underneath, several deep nuclei embedded in the white matter, and a fluid-filled ventricle in the middle. At the intermediate level, the cerebellum and its auxiliary structures can be broken down into several hundred or thousand independently functioning modules or compartments known as microzones. At the microscopic level, each module consists of the same small set of neuronal elements, laid out with a highly stereotyped geometry. Gross anatomy The human cerebellum is located at the base of the brain, with the large mass of the cerebrum above it, and the portion of the brainstem called the pons in front of it. It is separated from the overlying cerebrum by a layer of tough dura mater called the cerebellar tentorium; all of its connections with other parts of the brain travel through the pons. An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olivocerebellar Tract
The olivocerebellar tract, also known as olivocerebellar fibers, are neural fibers which originate at the olivary nucleus and pass out through the hilum and decussate with those from the opposite olive in the raphe nucleus, then as internal arcuate fibers they pass partly through and partly around the opposite olive and enter the inferior peduncle to be distributed to the cerebellar hemisphere The cerebellum consists of three parts, a median and two lateral, which are continuous with each other, and are substantially the same in structure. The median portion is constricted, and is called the vermis, from its annulated appearance which ... of the opposite side from which they arise. They terminate directly on Purkinje cells as the climbing fiber input system.Eccles J.C, Llinas R, and Sasaki. Excitation of cerebellar Purkinje cells by the climbing fibers. Nature 203: 245-246, 1964 References External links * Cerebellar connections {{Neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinocerebellar Tract
The spinocerebellar tracts are nerve tracts originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum. The two main tracts are the dorsal spinocerebellar tract, and the ventral spinocerebellar tract. Both of these tracts are located in the peripheral region of the lateral funiculi (white matter columns). Other tracts are the rostral spinocerebellar tract, and the cuneocerebellar tract (posterior external arcuate fibers). They carry proprioceptive, and cutaneous information to the cerebellum, where movement can be coordinated. Origins of proprioceptive information Proprioceptive information is obtained by Golgi tendon organs and muscle spindles. * Golgi tendon organs consist of a fibrous capsule enclosing tendon fascicles and bare nerve endings that respond to tension in the tendon by causing action potentials in type Ib afferents. These fibers are relatively large, myelinated, and quickly conducting. * Muscle spindles monitor the length ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestibulocerebellar Tract
The vestibulocerebellar tract fibers are second-order fibers from the vestibular nuclei, and first-order fibers from the vestibular ganglion/nerve. They pass through the juxtarestiform body of the inferior cerebellar peduncle to reach the cerebellum, They terminate in the vestibulocerebellum, and part of the vermis as well as the dentate nucleus, and fastigial nucleus in each hemisphere They are involved in maintaining balance. The first-order axons in the vestibulocerebellar tract terminate on the same side in the flocculonodular lobe; this direct projection to the cerebellum is a unique feature of the vestibular system The vestibular system, in vertebrates, is a sensory system that creates the sense of balance and spatial orientation for the purpose of coordinating motor coordination, movement with balance. Together with the cochlea, a part of the auditory sys .... References External links Brainstem Central nervous system pathways Cerebellar connections Vestib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System Pathways
Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as Middle Africa * Central America, a region in the centre of America continent * Central Asia, a region in the centre of Eurasian continent * Central Australia, a region of the Australian continent * Central Belt, an area in the centre of Scotland * Central Europe, a region of the European continent * Central London, the centre of London * Central Region (other) * Central United States, a region of the United States of America Specific locations Countries * Central African Republic, a country in Africa States and provinces * Blue Nile (state) or Central, a state in Sudan * Central Department, Paraguay * Central Province (Kenya) * Central Province (Papua New Guinea) * Central Province (Solomon Islands) * Central Province, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
