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Corticopontine Tract
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] |
Mid-brain
The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, motor control, sleep and wakefulness, arousal ( alertness), and temperature regulation.Breedlove, Watson, & Rosenzweig. Biological Psychology, 6th Edition, 2010, pp. 45-46 The name ''mesencephalon'' comes from the Greek ''mesos'', "middle", and ''enkephalos'', "brain". Structure The midbrain is the shortest segment of the brainstem, measuring less than 2cm in length. It is situated mostly in the posterior cranial fossa, with its superior part extending above the tentorial notch. The principal regions of the midbrain are the tectum, the cerebral aqueduct, tegmentum, and the cerebral peduncles. Rostrally the midbrain adjoins the diencephalon (thalamus, hypothalamus, etc.), while caudally it adjoins the hindbrain (pon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebrospinal Fibers
The cerebrospinal fibers, derived from the cells of the motor area of the cerebral cortex, occupy the middle three-fifths of the base; they are continued partly to the nuclei of the motor cranial nerves, but mainly into the pyramids of the medulla oblongata The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun .... References Central nervous system {{Portal bar, Anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontal Lobe
The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a Sulcus (neuroanatomy), groove between tissues called the central sulcus and from the temporal lobe by a deeper groove called the lateral sulcus (Sylvian fissure). The most anterior rounded part of the frontal lobe (though not well-defined) is known as the frontal pole, one of the three Cerebral hemisphere#Poles, poles of the cerebrum. The frontal lobe is covered by the frontal cortex. The frontal cortex includes the premotor cortex and the primary motor cortex – parts of the motor cortex. The front part of the frontal cortex is covered by the prefrontal cortex. The nonprimary motor cortex is a functionally defined portion of the frontal lobe. There are four principal Gyrus, gyri in the frontal lobe. The precentral gyrus is directly anterior to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occipitopontine 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 corticospi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporopontine Fibers
The temporopontine fibers are corticopontine fibers projecting from the temporal lobe to the pontine nuclei. The temporopontine fibers are lateral to the cerebrospinal fibers; they originate in the temporal lobe and end in the pontine nuclei. The fibers descend through the sublentiform part of the internal capsule The internal capsule is a paired white matter structure, as a two-way nerve tract, tract, carrying afferent nerve fiber, ascending and efferent nerve fiber, descending axon, fibers, to and from the cerebral cortex. The internal capsule is situate .... References Pons Temporal lobe Cerebral white matter {{Portal bar, Anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parietopontine 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 corticospina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontopontine Fibers
The frontopontine fibers or frontopontine tract are corticopontine fibers projecting from the cortex of the frontal lobe to the pons. In the internal capsule, the fibers descend predominately in the anterior limb (but some also in the posterior limb), passing inferior to the thalamus to reach the mesencephalon (midbrain) where they descend in the medial portion of base of the cerebral peduncles. In the pons, the fibers flare out between the pontine nuclei. Pathways Some of the frontopontine fibers participate in a pathway contributing to horizontal conjugate gaze: * Visual cortex → frontal eye fields (of the middle frontal gyrus) → frontopontine fibers → (contralateral) paramedian pontine reticular formation → (ipsilateral) abducens nucleus and (contralateral) oculomotor nucleus The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lobes Of The Brain
The lobes of the brain are the four major identifiable regions of the human cerebral cortex, and they comprise the surface of each hemisphere of the cerebrum. The two hemispheres are roughly symmetrical in structure, and are connected by the corpus callosum. Some sources include the insula and limbic lobe but the limbic lobe incorporates parts of the other lobes. The lobes are large areas that are anatomically distinguishable, and are also functionally distinct. Each lobe of the brain has numerous ridges, or gyri, and furrows, sulci that constitute further subzones of the cortex. The expression "lobes of the brain" usually refers only to those of the cerebrum, not to the distinct areas of the cerebellum. Frontal lobe The frontal lobe is located at the front of each cerebral hemisphere and positioned in front of the parietal lobe and above and in front of the temporal lobe. It is separated from the parietal lobe by a space between tissues called the central sulcus, and from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Cortex
The motor cortex is the region of the cerebral cortex involved in the planning, motor control, control, and execution of voluntary movements. The motor cortex is an area of the frontal lobe located in the posterior precentral gyrus immediately anterior to the central sulcus. Components The motor cortex can be divided into three areas: 1. The primary motor cortex is the main contributor to generating neural impulses that pass down to the spinal cord and control the execution of movement. However, some of the other motor areas in the brain also play a role in this function. It is located on the anterior paracentral lobule on the medial surface. 2. The premotor cortex is responsible for some aspects of motor control, possibly including the preparation for movement, the sensory guidance of movement, the spatial guidance of reaching, or the direct control of some movements with an emphasis on control of proximal and trunk muscles of the body. Located anterior to the primary mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neocerebellum
The posterior lobe of cerebellum or neocerebellum is one of the lobes of the cerebellum, below the primary fissure. The posterior lobe is much larger than anterior lobe. The anterior lobe is separated from the posterior lobe by the primary fissure, and the posterolateral fissure separates flocculonodular lobe from the posterior lobe. Sometimes, the posterior lobe of cerebellum is called the neocerebellum since phylogenetically it is the newest part of the cerebellum. It plays an important role in fine motor coordination, specifically in the inhibition of involuntary movement via inhibitory neurotransmitters, especially GABA. The posterior lobe receives input mainly from the brainstem (i.e., reticular formation The reticular formation is a set of interconnected nuclei in the brainstem that spans from the lower end of the medulla oblongata to the upper end of the midbrain. The neurons of the reticular formation make up a complex set of neural networks ... and inferior oli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral Pons
The basilar part of pons, also known as basis pontis, or basilar pons, is the ventral part of the pons (ventral pons) in the brainstem; the dorsal part (dorsal pons) is known as the pontine tegmentum. The basilar part of the pons makes up two thirds of the pons. It has a ridged appearance with a shallow groove at the midline. This groove is the basilar sulcus and is covered by the basilar artery. The basilar artery feeds into the circle of Willis providing blood supply to the brainstem and cerebellum. The ridged appearance is due to the fibers that come out of the pons to enter the cerebellum. The basilar pons contains fibers from the corticospinal tract (a descending pathway for neurons to reach other structures in the body), pontine nuclei, and transverse pontine fibers. The corticospinal tract carries fibres from the primary motor cortex to the spinal cord, aiding in voluntary motor movement of the body. In addition to passing through the ventral pons, corticospinal tract fibers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontine Nuclei
The pontine nuclei (or griseum pontis) are all the neurons of the ventral pons. Corticopontine fibres project from the primary motor cortex to the ipsilateral pontine nucleus; pontocerebellar fibers then relay the information to the contralateral cerebellum via the middle cerebellar peduncle. They are involved in motor function: the pontine nuclei are involved in adjusting movements according to their outcome (movement error correction), and are therefore important in learning motor skills. Anatomy The pontine nuclei encompass all of the about 20 million neurons scattered throughout the basilar part of pons. The pontine nuclei nuclei extend caudally into the medulla oblongata as the arcuate nucleus which is functionally homologous with the pontine nuclei. Afferents Corticopontine fibres arise primarily from the neocortex layer V of the premotor, somatosensory, non- striate visual, posterior parietal, and cingulate cerebral cortex; there are also a few fibers originating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
