|
Lateral Reticular Nucleus
The lateral reticular nucleus, of the lateral funiculus, can be divided into three subnuclei, the parvocellular, magnocellular and the ''subtrigeminal''. As is typical of the reticular formation, none of these are very distinct subnuclei, but rather blurred distinctions between cell types and location. The lateral reticular nucleus sends all of its projections to the cerebellum. * The parvocellular portion of the LRN and the immediately adjacent magnocellular portion send most their projections to the vermis of the cerebellum. The rest of the magnocellular subnucleus sends its projections to the hemisphere regions of the cerebellum. * The subtrigeminal nucleus sends its projections to the flocculonodular lobe. All of these efferent pathways are projected in an ipsilateral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Funiculus
The most lateral of the bundles of the anterior nerve roots In anatomy and neurology, the ventral root of spinal nerve, anterior root, or motor root is the efferent motor root of a spinal nerve. At its distal end, the ventral root joins with the dorsal root The dorsal root of spinal nerve (or posterior r ... is generally taken as a dividing line that separates the anterolateral system into two parts. These are the anterior funiculus, between the anterior median fissure and the most lateral of the anterior nerve roots, and the lateral funiculus (or lateral column) between the exit of these roots and the posterolateral sulcus. The lateral funiculus transmits the contralateral corticospinal and spinothalamic tracts. A lateral cutting of the spinal cord results in the transection of both ipsilateral posterior column and lateral funiculus and this produces Brown-Séquard syndrome.Kaplan Qbook - USMLE Step 1 - 5th edition - page References Central nervous system { ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parvocellular Cell
Parvocellular cells, also called P-cells, are neurons located within the parvocellular layers of the lateral geniculate nucleus (LGN) of the thalamus. "''Parvus''" is Latin for "small", and the name "parvocellular" refers to the small size of the cell compared to the larger magnocellular cells. Phylogenetically, parvocellular neurons are more modern than magnocellular ones. Function The parvocellular neurons of the visual system receive their input from midget cells, a type of retinal ganglion cell, whose axons are exiting the optic tract. These synapses occur in one of the four dorsal parvocellular layers of the lateral geniculate nucleus. The information from each eye is kept separate at this point, and continues to be segregated until processing in the visual cortex. The electrically-encoded visual information leaves the parvocellular cells via relay cells in the optic radiations, traveling to the primary visual cortex layer 4C-β. The parvocellular neurons are s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnocellular Cell
Magnocellular cells, also called M-cells, are neurons located within the Adina magnocellular layer of the lateral geniculate nucleus of the thalamus. The cells are part of the visual system. They are termed "magnocellular" since they are characterized by their relatively large size compared to parvocellular cells. Structure The full details of the flow of signaling from the eye to the visual cortex of the brain that result in the experience of vision are incompletely understood. Many aspects are subject to active controversy and the disruption of new evidence. In the visual system, signals mostly travel from the retina to the lateral geniculate nucleus (LGN) and then to the visual cortex. In humans the LGN is normally described as having six distinctive layers. The inner two layers, (1 and 2) are magnocellular cell (M cell) layers, while the outer four layers, (3,4,5 and 6), are parvocellular cell (P cell) layers. An additional set of neurons, known as the koniocellular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (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 or even larger. In humans, the cerebellum plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language as well as 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 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 movement, equilibrium, posture, and motor learning in humans. Anatomically, the human cerebellum has the appearance of a separate structure attached to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vermis
The cerebellar vermis (from Latin ''vermis,'' "worm") is located in the medial, cortico-nuclear zone of the cerebellum, which is in the posterior fossa of the cranium. The primary fissure in the vermis curves ventrolaterally to the superior surface of the cerebellum, dividing it into anterior and posterior lobes. Functionally, the vermis is associated with bodily posture and locomotion. The vermis is included within the spinocerebellum and receives somatic sensory input from the head and proximal body parts via ascending spinal pathways. The cerebellum develops in a rostro-caudal manner, with rostral regions in the midline giving rise to the vermis, and caudal regions developing into the cerebellar hemispheres. By 4 months of prenatal development, the vermis becomes fully foliated, while development of the hemispheres lags by 30–60 days. Postnatally, proliferation and organization of the cellular components of the cerebellum continues, with completion of the foliation p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flocculonodular Lobe
The flocculonodular lobe ( vestibulocerebellum) is a lobe of the cerebellum consisting of the nodule and the flocculus. The two flocculi are connected to the midline structure called the nodulus by thin pedicles. It is placed on the anteroinferior surface of cerebellum. This region of the cerebellum has important connections to the vestibular nuclei and uses information about head movement to influence eye movement. Lesions to this area can result in multiple deficits in visual tracking and oculomotor control (such as nystagmus and vertigo), integration of vestibular information for eye and head control, as well as control of axial muscles for balance. This lobe is also involved in the maintenance of balance equilibrium and muscle tone. The most common cause of damage to the flocculonodular lobe is medulloblastoma in childhood. References External links NIF Search - Flocculonodular lobevia the Neuroscience Information Framework The Neuroscience Information Framework is a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ipsilateral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhalation
Inhalation (or Inspiration) happens when air or other gases enter the lungs. Inhalation of air Inhalation of air, as part of the cycle of breathing, is a vital process for all human life. The process is autonomic (though there are exceptions in some disease states) and does not need conscious control or effort. However, breathing can be consciously controlled or interrupted (within limits). Breathing allows oxygen (which humans and a lot of other species need for survival) to enter the lungs, from where it can be absorbed into the bloodstream. Other substances – accidental Examples of accidental inhalation includes inhalation of water (e.g. in drowning), smoke, food, vomitus and less common foreign substances (e.g. tooth fragments, coins, batteries, small toy parts, needles). Other substances – deliberate Recreational use Legal – helium, nitrous oxide (" laughing gas") Illegal – various gaseous, vaporised or aerosolized recreational drugs Medical use D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Horn Of Spinal Cord
The posterior grey column (posterior cornu, dorsal horn, spinal dorsal horn, posterior horn, sensory horn) of the spinal cord is one of the three grey columns of the spinal cord. It receives several types of sensory information from the body, including fine touch, proprioception, and vibration. This information is sent from receptors of the skin, bones, and joints through sensory neurons whose cell bodies lie in the dorsal root ganglion. Anatomy The posterior grey column is subdivided into six layers termed Rexed laminae I-VI * Marginal nucleus of spinal cord (lamina I) * Substantia gelatinosa of Rolando (lamina II) *Nucleus proprius (laminae III, IV) * Spinal lamina V, the neck of the posterior horn * Spinal lamina VI, the base of the posterior horn. The other four Rexed laminae are located in the other two grey columns in the spinal cord. Additional images File:Gray687.png, Section of the medulla oblongata through the lower part of the decussation of the pyramids See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
