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Trapezoid Body
The trapezoid body (the ventral acoustic stria) is part of the auditory pathway where some of the axons coming from the cochlear nucleus (specifically, the anterior cochlear nucleus) decussate (cross over) to the other side before traveling on to the superior olivary nucleus. This is believed to help with localization of sound. The trapezoid body is located in the caudal pons, or more specifically the pontine tegmentum. It is situated between the pontine nuclei and the medial lemniscus. After nerves from the cochlear nucleus cross over in the trapezoid body and go on to the superior olivary nucleus, they continue to the lateral lemniscus, then the inferior colliculus, then the medial geniculate body, before finally arriving at the primary auditory cortex The auditory cortex is the part of the temporal lobe that processes auditory information in humans and many other vertebrates. It is a part of the auditory system, performing basic and higher functions in hearing, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochlear Nerve
The cochlear nerve (also auditory nerve or acoustic nerve) is one of two parts of the vestibulocochlear nerve, a cranial nerve present in amniotes, the other part being the vestibular nerve. The cochlear nerve carries auditory sensory information from the cochlea of the inner ear directly to the brain. The other portion of the vestibulocochlear nerve is the vestibular nerve, which carries spatial orientation information to the brain from the semicircular canals, also known as semicircular ducts. Anatomy and connections In terms of anatomy, an auditory nerve fiber is either bipolar or unipolar, with its distal projection being called the peripheral process, and its proximal projection being called the axon; these two projections are also known as the "peripheral axon" and the "central axon", respectively. The peripheral process is sometimes referred to as a dendrite, although that term is somewhat inaccurate. Unlike the typical dendrite, the peripheral process generates and cond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Pathway
Auditory means of or relating to the process of hearing: * Auditory system, the neurological structures and pathways of sound perception ** Auditory bulla, part of auditory system found in mammals other than primates ** Auditory nerve, also known as the cochlear nerve is one of two parts of a cranial nerve ** Auditory ossicles, three bones in the middle ear that transmit sounds * Hearing (sense), the auditory sense, the sense by which sound is perceived * Ear, the auditory end organ * Cochlea, the auditory branch of the inner ear * Sound, the physical signal perceived by the auditory system * External auditory meatus, the ear canal * Primary auditory cortex, the part of the higher-level of the brain that serves hearing * Auditory agnosia * Auditory exclusion, a form of temporary hearing loss under high stress * Auditory feedback, an aid to control speech production and singing * Auditory hallucination, perceiving sounds without auditory stimulus * Auditory illusion, sound trick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Auditory Cortex
The auditory cortex is the part of the temporal lobe that processes auditory information in humans and many other vertebrates. It is a part of the auditory system, performing basic and higher functions in hearing, such as possible relations to language switching.Cf. Pickles, James O. (2012). ''An Introduction to the Physiology of Hearing'' (4th ed.). Bingley, UK: Emerald Group Publishing Limited, p. 238. It is located bilaterally, roughly at the upper sides of the temporal lobes – in humans, curving down and onto the medial surface, on the superior temporal plane, within the lateral sulcus and comprising parts of the transverse temporal gyri, and the superior temporal gyrus, including the planum polare and planum temporale (roughly Brodmann areas 41 and 42, and partially 22). The auditory cortex takes part in the spectrotemporal, meaning involving time and frequency, analysis of the inputs passed on from the ear. The cortex then filters and passes on the information to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Geniculate Body
The medial geniculate nucleus (MGN) or medial geniculate body (MGB) is part of the auditory thalamus and represents the thalamic relay between the inferior colliculus (IC) and the auditory cortex (AC). It is made up of a number of sub-nuclei that are distinguished by their neuronal morphology and density, by their afferent and efferent connections, and by the coding properties of their neurons. It is thought that the MGN influences the direction and maintenance of attention. Divisions The MGN has three major divisions; ventral (VMGN), dorsal (DMGN) and medial (MMGN). Whilst the VMGN is specific to auditory information processing, the DMGN and MMGN also receive information from non-auditory pathways. Ventral subnucleus Cell types There are two main cell types in the ventral subnucleus of the medial geniculate body (VMGN): * Thalamocortical relay cells (or principal neurons): The dendritic input to these cells comes from two sets of dendritic trees oriented on opposite poles of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Colliculus
The inferior colliculus (IC) (Latin for ''lower hill'') is the principal midbrain nucleus of the auditory pathway and receives input from several peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex. The inferior colliculus has three subdivisions: the central nucleus, a dorsal cortex by which it is surrounded, and an external cortex which is located laterally. Its bimodal neurons are implicated in auditory-somatosensory interaction, receiving projections from somatosensory nuclei. This multisensory integration may underlie a filtering of self-effected sounds from vocalization, chewing, or respiration activities. The inferior colliculi together with the superior colliculi form the eminences of the corpora quadrigemina, and also part of the tectal region of the midbrain. The inferior colliculus lies caudal to its counterpart – the superior colliculus – above the trochlear nerve, and at the base of the projection of the medial genicu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Lemniscus
The lateral lemniscus is a tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain. Three distinct, primarily inhibitory, cellular groups are located interspersed within these fibers, and are thus named the nuclei of the lateral lemniscus. Connections There are three small nuclei on each of the lateral lemnisci: * the intermediate nucleus of the lateral lemniscus (INLL) * the ventral nucleus of the lateral lemniscus (VNLL) * the dorsal nucleus of the lateral lemniscus (DNLL) Fibers leaving these brainstem nuclei ascending to the inferior colliculus rejoin the lateral lemniscus. In that sense, this is not a ' lemniscus' in the true sense of the word (second order, decussated sensory axons), as there is third (and out of the lateral superior olive, fourth) order information coming out of some of these brainstem nuclei. The lateral lemniscus is loca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Lemniscus
In neuroanatomy, the medial lemniscus, also known as Reil's band or Reil's ribbon (for German anatomist Johann Christian Reil), is a large ascending bundle of heavily myelinated axons that decussate (cross) in the brainstem, specifically in the medulla oblongata. The medial lemniscus is formed by the crossings of the internal arcuate fibers. The internal arcuate fibers are composed of axons of nucleus gracilis and nucleus cuneatus. The axons of the nucleus gracilis and nucleus cuneatus in the medial lemniscus have cell bodies that lie contralaterally. The medial lemniscus is part of the dorsal column–medial lemniscus pathway, which ascends from the skin to the thalamus, which is important for somatosensation from the skin and joints, therefore, lesion of the medial lemnisci causes an impairment of vibratory and touch-pressure sense. Etymology Lemniscus means "ribbon", so named because the medial lemniscus "spirals" or "turns" as it ascends. Path After neurons carrying propri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontine Nuclei
Pontine may refer to: * Having to do with the pons, a structure located in the brain stem (from ''pons'', "bridge") * Pontine Marshes, a region of Italy near Rome * Pontine Islands The Pontine Islands (, also ; it, Isole Ponziane ) are an archipelago in the Tyrrhenian Sea off the coast of Lazio region, Italy. The islands were collectively named after the largest island in the group, Ponza. The other islands in the archipe ..., islands of Italy near Circeo See also {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontine Tegmentum
Pontine may refer to: * Having to do with the pons, a structure located in the brain stem (from ''pons'', "bridge") * Pontine Marshes, a region of Italy near Rome * Pontine Islands The Pontine Islands (, also ; it, Isole Ponziane ) are an archipelago in the Tyrrhenian Sea off the coast of Lazio region, Italy. The islands were collectively named after the largest island in the group, Ponza. The other islands in the archipe ..., islands of Italy near Circeo See also {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pons
The pons (from Latin , "bridge") is part of the brainstem that in humans and other bipeds lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum. The pons is also called the pons Varolii ("bridge of Varolius"), after the Italian anatomist and surgeon Costanzo Varolio (1543–75). This region of the brainstem includes neural pathways and tracts that conduct signals from the brain down to the cerebellum and medulla, and tracts that carry the sensory signals up into the thalamus.Saladin Kenneth S.(2007) Anatomy & physiology the unity of form and function. Dubuque, IA: McGraw-Hill Structure The pons is in the brainstem situated between the midbrain and the medulla oblongata, and in front of the cerebellum. A separating groove between the pons and the medulla is the inferior pontine sulcus. The superior pontine sulcus separates the pons from the midbrain. The pons can be broadly divided into two parts: the basilar part of the pons (ventral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Olivary Complex
The superior olivary complex (SOC) or superior olive is a collection of brainstem nuclei that functions in multiple aspects of hearing and is an important component of the ascending and descending auditory pathways of the auditory system. The SOC is intimately related to the trapezoid body: most of the cell groups of the SOC are dorsal (posterior in primates) to this axon bundle while a number of cell groups are embedded in the trapezoid body. Overall, the SOC displays a significant interspecies variation, being largest in bats and rodents and smaller in primates. Physiology The superior olivary nucleus plays a number of roles in hearing. The medial superior olive (MSO) is a specialized nucleus that is believed to measure the time difference of arrival of sounds between the ears (the interaural time difference or ITD). The ITD is a major cue for determining the azimuth of sounds, i.e., localising them on the azimuthal plane – their degree to the left or the right. The lateral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochlear Nucleus
The cochlear nuclear (CN) complex comprises two cranial nerve nuclei in the human brainstem, the ventral cochlear nucleus (VCN) and the dorsal cochlear nucleus (DCN). The ventral cochlear nucleus is unlayered whereas the dorsal cochlear nucleus is layered. Auditory nerve fibers, fibers that travel through the auditory nerve (also known as the cochlear nerve or eighth cranial nerve) carry information from the inner ear, the cochlea, on the same side of the head, to the nerve root in the ventral cochlear nucleus. At the nerve root the fibers branch to innervate the ventral cochlear nucleus and the deep layer of the dorsal cochlear nucleus. All acoustic information thus enters the brain through the cochlear nuclei, where the processing of acoustic information begins. The outputs from the cochlear nuclei are received in higher regions of the auditory brainstem. Structure The cochlear nuclei (CN) are located at the dorso-lateral side of the brainstem, spanning the junction of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
