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Heterotypic Cortex
Heterotypic cortex consists of those areas of the mature neocortex that deviate markedly from the homogeneous six-layered internal structure seen in the third trimester of human gestation. A few neocortical areas, such as Brodmann area 17 and the granular insular cortex, undergo modification to more than six layers; and in a few areas, such as Brodmann area 4 Brodmann area 4 refers to the primary motor cortex of the human brain. It is located in the posterior portion of the frontal lobe. Brodmann area 4 is part of the precentral gyrus. The borders of this area are: the precentral sulcus in front ( ..., the number of layers is reduced. Heterotypic cortex is contrasted to homotypic cortex, which retains the fetal six-layered pattern into adulthood. The number of heterotypic areas is small and the specific areas differ somewhat by species. (English translation available as ) References External links * More information aBrainInfo Cerebral cortex {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neocortex
The neocortex, also called the neopallium, isocortex, or the six-layered cortex, is a set of layers of the mammalian cerebral cortex involved in higher-order brain functions such as sensory perception, cognition, generation of motor commands, spatial reasoning and language. The neocortex is further subdivided into the true isocortex and the proisocortex. In the human brain, the neocortex is the largest part of the cerebral cortex (the outer layer of the cerebrum). The neocortex makes up the largest part of the cerebral cortex, with the allocortex making up the rest. The neocortex is made up of six layers, labelled from the outermost inwards, I to VI. Etymology The term is from ''cortex'', Latin, " bark" or "rind", combined with ''neo-'', Greek, "new". ''Neopallium'' is a similar hybrid, from Latin ''pallium'', "cloak". ''Isocortex'' and ''allocortex'' are hybrids with Greek ''isos'', "same", and ''allos'', "other". Anatomy The neocortex is the most developed in its organisat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Gestation
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but can also occur through assisted reproductive technology procedures. A pregnancy may end in a live birth, a miscarriage, an induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP), a span known as the gestational age. This is just over nine months. Counting by fertilization age, the length is about 38 weeks. Pregnancy is "the presence of an implanted human embryo or fetus in the uterus"; implantation occurs on average 8–9 days after fertilization. An '' embryo'' is the term for the developing offspring during the first seven weeks following implantation (i.e. ten weeks' gestational age), after which the term ''fetus'' is used until birth. Signs an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brodmann Area 17
The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. The area of the visual cortex that receives the sensory input from the lateral geniculate nucleus is the primary visual cortex, also known as visual area 1 ( V1), Brodmann area 17, or the striate cortex. The extrastriate areas consist of visual areas 2, 3, 4, and 5 (also known as V2, V3, V4, and V5, or Brodmann area 18 and all Brodmann area 19). Both hemispheres of the brain include a visual cortex; the visual cortex in the left hemisphere receives signals from the right visual field, and the visual cortex in the right hemisphere receives signals from the left visual field. Introduction The primary visual cortex (V1) is located in and around the calcarine fissure in the occipital lobe. Each hemisphere's V1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granular Insular Cortex
Granular insular cortex (or visceral area) refers to a portion of the cerebral cortex defined on the basis of internal structure in the human and macaque, the rat, and the mouse. Classified as neocortex, it is in primates distinguished from adjacent allocortex (periallocortex) by the presence of granular layers – external granular layer (II) and internal granular layer (IV) – and by differentiation of the external pyramidal layer (III) into sublayers. In primates it occupies the posterior part of the insula. In rodents it is located on the lateral surface of the cortex rostrally, dorsal to the gustatory area or, more caudally, dorsal to the agranular insula. See also * Agranular insula Agranular insula is a portion of the cerebral cortex defined on the basis of internal structure in the human, the macaque, the rat, and the mouse. Classified as allocortex (periallocortex), it is in primates distinguished from adjacent neocortex ( ... References External links * More i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brodmann Area 4
Brodmann area 4 refers to the primary motor cortex of the human brain. It is located in the posterior portion of the frontal lobe. Brodmann area 4 is part of the precentral gyrus. The borders of this area are: the precentral sulcus in front ( anteriorly), the medial longitudinal fissure at the top ( medially), the central sulcus in back (posteriorly), and the lateral sulcus along the bottom (laterally). This area of cortex, as shown by Wilder Penfield and others, has the pattern of a homunculus. That is, the legs and trunk fold over the midline; the arms and hands are along the middle of the area shown here; and the face is near the bottom of the figure. Because Brodmann area 4 is in the same general location as primary motor cortex, the homunculus here is called the motor homunculus. The term area 4 of Brodmann-1909 refers to a cytoarchitecturally defined portion of the frontal lobe of the guenon. It is located predominantly in the precentral gyrus. Brodmann-1909 rega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
