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Nucleus Of Darkschewitsch
The nucleus of Darkschewitsch is an accessory oculomotor nucleus situated in the ventrolateral portion of the periaqueductal gray of the mesencephalon (midbrain) near its junction with the diencephalon. It is involved in mediating vertical eye movements. It projects to the trochlear nucleus, receives afferents from the visual cortex, and forms a reciprocal (looping) connection with the cerebellum by way of the inferior olive. Anatomy Connections It receives afferents from the visual association areas (via the corticotectal tract), vestibular nuclei (via the medial longitudinal fasciculus), and from the spinomesencephalic tract. It gives rise to the medial tegmental tract to project efferents to the (rostral portion of) medial accessory olivary nucleus → ((decussation) inferior cerebellar peduncle → (contralateral) globose nucleus of cerebellum → superior cerebellar peduncle (decussation) → (rostral part of) medial accessory olivary nucleus → (ipsilateral) nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midbrain
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. Rostral and caudal, Rostrally the midbrain adjoins the diencephalon (thalamus, hypothalamus, etc.), while Rostral and caudal, cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinomesencephalic Tract
The spinomesencephalic pathway, spinomesencephalic tract or spino-quadrigeminal system of Mott, includes a number of ascending tracts in the spinal cord, including the spinotectal tract. The spinomesencephalic tract is one of the ascending tracts in the anterolateral system of the spinal cord that projects to various parts of the midbrain. It is involved in the processing of pain and visceral sensations. In the ALS The anterolateral system (ALS) is a bundle of afferent somatosensory fibers from different ascending tracts in the spinal cord. These fibers include those of the spinomesencephalic tract, spinothalamic tract, and spinoreticular tract amongst others. Spinomesencephalic fibres project to the periaqueductal gray, and to the tectum. Other fibers project to and terminate in the parabrachial nucleus, the pretectum, and the nucleus of Darkschewitsch. The fibers that project to the tectum are known as the spinotectal fibers. The spinotectal tract fibers project to the superior co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstitial Nucleus Of Cajal
The interstitial nucleus of Cajal is a collection of neurons in the mesencephalon (midbrain) which are involved in integrating eye position-velocity information in order to coordinate head-eye movements - especially those related to vertical and torsional conjugate eye movements (gaze). It also mediates vertical gaze holding. Bilateral projections to the oculomotor (cranial nerve III) and trochlear (cranial nerve IV) nuclei represent its principal outputs. It forms reciprocal connections with vestibular nuclei. It also has additional afferents and efferents. Some of the nucleus' connections pass through the medial longitudinal fasciculus, and the posterior commissure. It is one of the accessory oculomotor nuclei. Anatomy The interstitial nucleus of Cajal is a diffuse collection of mid-sized, parvalbumin-containing premotor neurons of the midbrain reticular formation. Connections The nucleus forms reciprocal connections with the vestibular nuclei (through the MLF). It f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 for a short distance into the floor of the third ventricle. From this nucleus the fibers pass forward through the tegmentum, the red nucleus, and the medial part of the substantia nigra, forming a series of curves with a lateral convexity, and emerge from the oculomotor sulcus on the medial side of the cerebral peduncle. The nucleus of the oculomotor nerve does not consist of a continuous column of cells, but is broken up into a number of smaller nuclei, which are arranged in two groups, anterior and posterior. Those of the posterior group are six in number, five of which are symmetrical on the two sides of the middle line, while the sixth is centrally placed and is common to the nerves of both sides. The anterior group consists of two nuclei, an antero-medial and an antero-lateral. The nucleus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Cerebellar Peduncle
In the human brain, the superior cerebellar peduncle (brachium conjunctivum) is one of the three paired cerebellar peduncles of bundled fibers that connect the cerebellum to the brainstem. The superior cerebellar peduncle connects to the midbrain. It consists mainly of efferent fibers, the cerebellothalamic tract that runs from a cerebellar hemisphere to the contralateral thalamus, and the cerebellorubral tract that runs from a cerebellar hemisphere to the red nucleus. It also contains afferent tracts, most prominent of which is the ventral spinocerebellar tract. Other afferent tracts are the ventral trigeminal tract, tectocerebellar fibers, and noradrenergic fibers from the locus coeruleus. The superior peduncle emerges from the upper and medial parts of the white matter of each cerebellar hemisphere and is placed under cover of the upper part of the cerebellum. Structure Superior cerebellar peduncles are connected together by the superior medullary velum, which can be fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or even larger. In humans, the cerebellum plays an important role in motor control and cognition, cognitive functions such as attention and language as well as emotion, emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to motor coordination, coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in fine motor skill, fine movement, sense of balance, equilibrium, list of human positions, posture, and motor learning in humans. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globose Nucleus
The globose nucleus is one of the deep cerebellar nuclei. It is located medial to the emboliform nucleus, and lateral to the fastigial nucleus. The ''globose nucleus'' and emboliform nucleus are known collectively as the interposed nuclei. The globose nucleus is part of a neural circuit giving rise to descending motor tracts involved in motor control of distal musculature of the upper and lower limbs. Anatomy Afferents * Purkinje cells of (the paravermal cortex of) the spinocerebellum * Anterior spinocerebellar tract (via restiform body of inferior cerebellar peduncle) Efferents * Contralateral (magnocellular division of) red nucleus (via the superior cerebellar peduncle). This is the major major efferent projection of the globose nucleus. The red nucleus in turn gives rise to the rubrospinal tract. * Ipsilateral ventral lateral nucleus of thalamus. The VL nucleus in turn projects to the primary motor cortex and premotor cortex (which then give rise to the lateral c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Cerebellar Peduncle
The inferior cerebellar peduncle is formed by fibers of the restiform body that join with fibers from the much smaller juxtarestiform body. The inferior cerebellar peduncle is the smallest of the three cerebellar peduncles. The upper part of the posterior district of the medulla oblongata is occupied by the inferior cerebellar peduncle, a thick rope-like strand situated between the lower part of the fourth ventricle and the roots of the glossopharyngeal and vagus nerves. Each cerebellar inferior peduncle connects the spinal cord and medulla oblongata with the cerebellum, and comprises the juxtarestiform body and restiform body. Important fibers running through the inferior cerebellar peduncle include the dorsal spinocerebellar tract and axons from the inferior olivary nucleus, among others. Function The inferior cerebellar peduncle carries many types of input and output fibers that are mainly concerned with integrating proprioceptive sensory input with motor vestibular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Olivary Complex
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] |
Medial Tegmental Tract
Medial may refer to: Mathematics * Medial magma, a mathematical identity in algebra Geometry * Medial axis, in geometry the set of all points having more than one closest point on an object's boundary * Medial graph, another graph that represents the adjacencies between edges in the faces of a plane graph * Medial triangle, the triangle whose vertices lie at the midpoints of an enclosing triangle's sides * Polyhedra: ** Medial deltoidal hexecontahedron ** Medial disdyakis triacontahedron ** Medial hexagonal hexecontahedron ** Medial icosacronic hexecontahedron ** Medial inverted pentagonal hexecontahedron ** Medial pentagonal hexecontahedron ** Medial rhombic triacontahedron Linguistics * A medial sound or letter is one that is found in the middle of a larger unit (like a word) ** Syllable medial, a segment located between the onset and the rime of a syllable * In the older literature, a term for the voiced stops (like ''b'', ''d'', ''g'') * Medial or second person demo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Longitudinal Fasciculus
The medial longitudinal fasciculus (MLF) is a prominent bundle of nerve fibres which pass within the ventral/anterior portion of periaqueductal gray of the mesencephalon (midbrain). It contains the interstitial nucleus of Cajal, responsible for oculomotor control, head posture, and vertical eye movement. The MLF interconnects interneurons of each abducens nucleus with motor neurons of the contralateral oculomotor nucleus; thus, the MLF mediates coordination of horizontal (side to side) eye movements, ensuring the two eyes move in unison (thus also enabling saccadic eye movements). The MLF also contains fibers projecting from the vestibular nuclei to the oculomotor and trochlear nuclei as well as the interstitial nucleus of Cajal; these connections ensure that eye movements are coordinated with head movements (as sensed by the vestibular system). The medial longitudinal fasciculus is the main central connection for the oculomotor nerve, trochlear nerve, and abduce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accessory Oculomotor Nuclei
The accessory oculomotor nuclei are a group of nuclei situated in the rostral mesencephalon (midbrain) near its junction with the diencephalon, and consist of: * Interstitial nucleus of Cajal * Rostral interstitial nucleus of medial longitudinal fasciculus * Nucleus of Darkschewitsch * Nucleus of the posterior commissure These nuclei are involved in vertical and rotatory gaze (physiology), and smooth pursuit. They receive afferents from the visual association area; they project efferents through the medial longitudinal fasciculus The medial longitudinal fasciculus (MLF) is a prominent bundle of nerve fibres which pass within the ventral/anterior portion of periaqueductal gray of the mesencephalon (midbrain). It contains the interstitial nucleus of Cajal, responsible ... to the nuclei of cranial nerves controlling extrinsic eye muscles. References {{Reflist Brainstem nuclei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
