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Frenulum Veli
The frenulum veli, or frenulum of superior medullary velum, also known as the ''frenulum veli medullaris superioris'', ''cerebellar frenulum'', or ''frenulum cerebelli'', is a slightly raised white band passing from the inferior end of the medial longitudinal fissure, through the groove between the quadrigeminal bodies, and down to the superior medullary velum. On either side of this band the trochlear nerve emerges, and passes forward on the lateral aspect of the cerebral peduncle The cerebral peduncles (In Latin, ''ped-'' means 'foot'.) are the two stalks that attach the cerebrum to the brainstem. They are structures at the front of the midbrain which arise from the ventral pons and contain the large ascending (sensor ... to reach the base of the brain. References * Crosby EC, Humphrey T, Lauer EW, ''Correlative Anatomy of the Nervous System'', New York: MacMillan, 1962. * Stedman, Thomas Lathrop, ''Stedman's Medical Dictionary'' (24th edition), Williams and Wilkins Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Medullary Velum
The superior medullary velum (anterior medullary velum) is a thin, transparent lamina of white matter which - together with the inferior medullary velum - forms the roof of the fourth ventricle. It extends between the two superior cerebellar peduncles. The lingula of cerebellum covers - and adheres to - its dorsal surface. Anatomy Relations The superior medullary velum extends between the dorsomedial margins of the two superior cerebellar peduncles. On the dorsal surface of its lower half the folia and lingula are prolonged. It forms, together with the superior cerebellar peduncle, the roof of the upper part of the fourth ventricle; it is narrow above, where it passes beneath the facial colliculi, and broader below, where it is continuous with the white substance of the superior vermis. A slightly elevated ridge, the frenulum veli, descends upon its upper part from between the inferior colliculi, and on either side of this the trochlear nerve emerges. Blood supply Bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Longitudinal Fissure
The longitudinal fissure (or cerebral fissure, great longitudinal fissure, median longitudinal fissure, interhemispheric fissure) is the deep groove that separates the two cerebral hemispheres of the vertebrate brain. Lying within it is a continuation of the dura mater (one of the meninges) called the falx cerebri. The inner surfaces of the two hemispheres are convoluted by gyri and sulci just as is the outer surface of the brain. Structure Falx cerebri All three meninges of the cortex ( dura mater, arachnoid mater, pia mater) fold and descend deep down into the longitudinal fissure, physically separating the two hemispheres. Falx cerebri is the name given to the dura mater in-between the two hemispheres, whose significance arises from the fact that it is the outermost layer of the meninges. These layers prevent any direct connectivity between the bilateral lobes of the cortex, thus requiring any tracts to pass through the corpus callosum. The vasculature of falx cerebri s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corpora Quadrigemina
In the brain, the corpora quadrigemina (Latin for "quadruplet bodies") are the four colliculi—two inferior, two superior—located on the tectum of the dorsal aspect of the 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, mo .... They are respectively named the inferior and superior colliculus. The corpora quadrigemina are reflex centers involving vision and hearing. It consists of groups of nerve cells-grey matter scattered in white matter. It basically connects the forebrain and the hind brain. It has four corpora quadrigemina which are the reflex centres of eye movement and auditory responses. The superior part of corpora quadrigemina are called superior colliculi, and inferior part as inferior colliculi.Marieb, Elaine N. Essentials of Human Anatomy & Physiology. 6th ed. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Medullary Velum
The superior medullary velum (anterior medullary velum) is a thin, transparent lamina of white matter which - together with the inferior medullary velum - forms the roof of the fourth ventricle. It extends between the two superior cerebellar peduncles. The lingula of cerebellum covers - and adheres to - its dorsal surface. Anatomy Relations The superior medullary velum extends between the dorsomedial margins of the two superior cerebellar peduncles. On the dorsal surface of its lower half the folia and lingula are prolonged. It forms, together with the superior cerebellar peduncle, the roof of the upper part of the fourth ventricle; it is narrow above, where it passes beneath the facial colliculi, and broader below, where it is continuous with the white substance of the superior vermis. A slightly elevated ridge, the frenulum veli, descends upon its upper part from between the inferior colliculi, and on either side of this the trochlear nerve emerges. Blood supply Bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trochlear Nerve
The trochlear nerve (), ( lit. ''pulley-like'' nerve) also known as the fourth cranial nerve, cranial nerve IV, or CN IV, is a cranial nerve that innervates a single muscle - the superior oblique muscle of the eye (which operates through the pulley-like trochlea). Unlike most other cranial nerves, the trochlear nerve is exclusively a motor nerve ( somatic efferent nerve). The trochlear nerve is unique among the cranial nerves in several respects: * It is the ''smallest'' nerve in terms of the number of axons it contains. * It has the greatest intracranial length. * It is the only cranial nerve that exits from the dorsal (rear) aspect of the brainstem. * It innervates a muscle, the superior oblique muscle, on the opposite side (contralateral) from its nucleus. The trochlear nerve decussates within the brainstem before emerging on the contralateral side of the brainstem (at the level of the inferior colliculus). An injury to the trochlear nucleus in the brainstem will result i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Peduncle
The cerebral peduncles (In Latin, ''ped-'' means 'foot'.) are the two stalks that attach the cerebrum to the brainstem. They are structures at the front of the midbrain which arise from the ventral pons and contain the large ascending (sensory) and descending (motor) tracts that run to and from the cerebrum from the pons. Mainly, the three common areas that give rise to the cerebral peduncles are the cerebral cortex, the spinal cord and the cerebellum. The region includes the tegmentum, crus cerebri and pretectum. By this definition, the cerebral peduncles are also known as the basis pedunculi, while the large ventral bundle of efferent fibers is referred to as the cerebral crus (''crus'' means ‘leg’ in Latin.) or the pes pedunculi (''pes'' means 'foot' in Latin.). The cerebral peduncles are located on either side of the midbrain and are the frontmost part of the midbrain, and act as the connectors between the rest of the midbrain and the thalamic nuclei and thus the cer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
