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Encyclopedia > Occipital lobe
Brain: Occipital lobe
Lobes of the human brain (the occipital lobe is shown in red)
Medial surface of left cerebral hemisphere. (cuneus and lingual gyrus are at left.)
Latin lobus occipitalis
Gray's subject #189 823
NeuroNames hier-122
MeSH Occipital+Lobe

The occipital lobe is the visual processing center of the mammalian brain, containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1 (visual one). Human V1 is located on the medial side of the occipital lobe within the calcarine sulcus; the full extent of V1 often continues onto the posterior pole of the occipital lobe. V1 is often also called striate cortex because it can be identified by a large stripe of myelin, the Stria of Gennari. Visually driven regions outside V1 are called extrastriate cortex. There are many extrastriate regions, and these are specialized for different visual tasks, such as visuospatial processing, color discrimination and motion perception. Image File history File links Question_book-3. ... Image File history File links Lobes_of_the_brain_NL.svg‎ Lobes of the brain image without labels. ... The frontal lobe is an area in the brain of mammals. ... The temporal lobes are part of the cerebrum. ... The parietal lobe is a lobe in the brain. ... Image File history File links No higher resolution available. ... Cuneus (Latin for wedge; plural, cunei), the architectural term applied to the wedge-shaped divisions of the Roman theatre separated by the scalae or stairways; see Vitruvius v. ... The lingual gyrus of the occipital lobe lies between the calcarine fissure and the posterior part of the collateral fissure; behind, it reaches the occipital pole; in front, it is continued on to the tentorial surface of the temporal lobe, and joins the hippocampal gyrus. ... For other uses, see Latin (disambiguation). ... NeuroNames is a system of nomenclature for the brain and related structures. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... In psychology, visual perception is the ability to interpret visible light information reaching the eyes which is then made available for planning and action. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including those that produce milk, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... For other uses, see Brain (disambiguation). ... Brodmann area 17 (primary visual cortex) is shown in red in this image which also shows area 18 (orange) and 19 (yellow) The visual cortex refers to the primary visual cortex (also known as striate cortex or V1) and extrastriate visual cortical areas such as V2, V3, V4, and V5. ... Brodmann area 17 (primary visual cortex) is shown in red in this image which also shows area 18 (orange) and 19 (yellow) The primary visual cortex (usually called V1) is the most well-studied visual area in the brain. ... A Brodmann area is a region in the brain cortex defined in many different species based on its cytoarchitecture. ... Look up medial in Wiktionary, the free dictionary. ... The calcarine fissure (or calcarine sulcus) is on the medial surface of the hemisphere. ... The stria of Gennari (also band or line of Gennari) is a band of myelinated axons projecting into layer 4C of the primary visual cortex from the lateral geniculate nucleus. ... This term refers the region of the cortex of the mammalian brain located next to the striate cortex (also known as primary visual cortex). ...

Contents

Anatomy

The occipital lobes are the smallest of four true lobes in the human brain. Located in the rearmost portion of the skull, the occipital lobes are part of the forebrain structure. The human brain as viewed from above, showing the cerebral hemispheres. ...


The lobes rest on the tentorium cerebelli, a process of dura mater that separates the cerebrum from the cerebellum. They are structurally isolated in their respective cerebral hemispheres by the separation of the cerebral fissure. The front edge of the occipital lobe is separated from the parietal lobe by the Parieto-occipital sulcus. The sides of the lobe merge with the parietal lobes along a vague boundary defined by several lateral occipital gyri, which are separated by lateral occipital sulcus. The cerebellum (Latin: little brain) is a region of the brain that plays an important role in the integration of sensory perception and motor output. ... The medial longitudinal fissure (or longitudinal cerebral fissure, or longitudinal fissure, or interhemispheric fissure) is the deep groove which separates the two hemispheres of the vertebrate brain. ... The parietal lobe is a lobe in the brain. ... Only a small part of the Parietoöccipital Fissure (or parieto-occipital sulcus) is seen on the lateral surface of the hemisphere, its chief part being on the medial surface. ...


The occipital aspects along the inside face of each hemisphere are divided by the calcarine sulcus. Above the medial, Y-shaped sulcus lies the cuneus, and the area below the sulcus is the lingual gyrus. The calcarine fissure (or calcarine sulcus) is on the medial surface of the hemisphere. ... Cuneus (Latin for wedge; plural, cunei), the architectural term applied to the wedge-shaped divisions of the Roman theatre separated by the scalae or stairways; see Vitruvius v. ... The lingual gyrus of the occipital lobe lies between the calcarine fissure and the posterior part of the collateral fissure; behind, it reaches the occipital pole; in front, it is continued on to the tentorial surface of the temporal lobe, and joins the hippocampal gyrus. ...


Function

Retinal sensors convey stimuli through the optic tracts to the lateral geniculate bodies, where optic radiations continue to the smelling cortex. Each smelling cortex receives raw sensory information from the outside half of the retina on the same side of the head and from the inside half of the retina on the other side of the head. The lateral geniculate nucleus (LGN) of the thalamus is a part of the brain, which is the primary processor of visual information, received from the retina, in the CNS. Schematic diagram of the primate lateral geniculate nucleus. ...


Cells on the posterior aspect of the occipital lobes' gray matter are arranged as a spinal map of the retinal field. Functional neuroimaging reveals similar patterns of response in cortical tissue of the lobes when the retinal fields are exposed to a strong pattern. Grey matter (or gray matter) is a major component of the central nervous system, consisting of nerve cell bodies, glial cells (astroglia and oligodendrocytes), capillaries, and short nerve cell extensions/processes (axons and dendrites). ... Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions. ...


If one occipital lobe is ADD, the result can be homo vision loss from similarly positioned "field cuts" in each eye. Occipital lesions can cause visual hallucinations. Lesions in the parietal-temporal-occipital association area are associated with color agnosia, movement agnosia, and agraphia. Headline text COLOR AGNOSIA http://nanonline. ... Agraphia is inability to write resulting from brain disease. ...


The function of the occipital lobe is to control vision and color recognition.


Functional anatomy

The occipital lobe is divided into several functional visual areas. Each visual area contains a full map of the visual world. Although there are no anatomical markers distinguishing these areas (except for the prominent striations in the striate cortex), physiologists have used electrode recordings to divide the cortex into different functional regions. Brodmann area 17 (primary visual cortex) is shown in red in this image which also shows area 18 (orange) and 19 (yellow) The primary visual cortex (usually called V1) is the most well-studied visual area in the brain. ...


The first functional area is the primary visual cortex. It contains a low-level description of the local orientation, spatial-frequency and color properties within small receptive fields. Primary visual cortex projects to the occipital areas of the ventral stream (visual area V2 and visual area V4), and the occipital areas of the dorsal stream - visual area V3, visual area MT (V5), and visual area DP. Brodmann area 17 (primary visual cortex) is shown in red in this image which also shows area 18 (orange) and 19 (yellow) The primary visual cortex (usually called V1) is the most well-studied visual area in the brain. ... Receptive fields are areas of the retina, producing a change in the firing of cells in the visual system. ... Brodmann area 17 (primary visual cortex) is shown in red in this image which also shows area 18 (orange) and 19 (yellow) The primary visual cortex (usually called V1) is the most well-studied visual area in the brain. ... The primate visual system consists of about thirty areas of the cerebral cortex called the visual cortex. ... Visual area V2 is the second major area in the occipital lobe of the cerebral cortex. ... Visual area V4 is an one of the visual areas in the extrastriate visual cortex of the macaque monkey. ... The dorsal stream is a pathway for visual information which flows through the visual cortex, the part of the brain which provides visual processing. ... Visual area V3 is an area of cerebral cortex that has been defined in primates and humans. ... Visual Area MT MT or middle/medial temporal visual cortex (often referred to as V5) is a region in the Extrastriate cortex that appears to process complex visual motion stimuli. ...


Additional images

See also


  Results from FactBites:
 
NeurosurgeryToday.org | What is Neurosurgery | Patient Education Materials | anatomy of the brain (2607 words)
Messages can travel from one bulge on the brain to another (gyri to gyri), from one lobe to another, from one side of the brain to the other, from one lobe of the brain to structures that are found deep in the brain, e.g.
Occipital Lobes – These lobes are located at the back of the brain and enable humans to receive and process visual information.
The occipital lobe on the right interprets visual signals from the left visual space, while the left occipital lobe performs the same function for the right visual space.
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