| Brain: Corpus callosum | ||
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| Corpus callosum from below. (Anterior portion is at the top of the image. ) | ||
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| Median sagittal section of brain (person faces to the left). In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species Corpus callosum visible at center, in light gray. ) | ||
| Gray's | subject #189 828 | |
| NeuroNames | hier-173 | |
| MeSH | Corpus+Callosum | |
The corpus callosum is a structure of the mammalian brain in the longitudinal fissure that connects the left and right cerebral hemispheres. This is a list of the subjects in Gray's Anatomy: IX Neurology NeuroNames is a system of nomenclature for the human and/or macaque Brain. Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain A cerebral hemisphere ( hemispherium cerebrale) is defined as one of the two regions of the Brain that are delineated by the body's median plane. It is the largest white matter structure in the brain, consisting of 200-250 million contralateral axonal projections. White matter is one of the three main solid components of the Central nervous system. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species An axon or nerve fiber is a long slender projectionof a nerve cell or Neuron, that conducts electrical impulses away from the neuron's Cell It is a wide, flat bundle of axons beneath the cortex. The cerebral cortex is a structure within the Brain that plays a key role in Memory, Attention, perceptual Awareness, Thought, Much of the inter-hemispheric communication in the brain is conducted across the corpus callosum.
Monotremes and marsupials do not have a corpus callosum. Monotremes (from the Greek monos 'single' + trema 'hole' referring to the Cloaca) are Mammals that lay eggs ( Prototheria) instead Marsupials are an Infraclass of Mammals characterized by a distinctive pouch (called the marsupium) in which females carry their young through
Contents |
Review
The posterior portion of the corpus callosum is called the splenium; the anterior is called the genu (or "knee"); between the two is the 'body. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species The posterior end of the Corpus callosum is the thickest part and is termed the splenium. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species The anterior end of the Corpus callosum is named the genu, and is bent downward and backward in front of the Septum pellucidum; diminishing rapidly in thickness it '
The most anterior part is the rostrum. The anterior end of the Corpus callosum is named the Genu, and is bent downward and backward in front of the Septum pellucidum; diminishing rapidly in thickness it
Sexual dimorphism
There are disputed claims about the difference of the size of the human corpus callosum in men and women and the relationship of any such differences to gender differences in human behaviour and cognition.
R B Bean, a Philadelphia anatomist, suggested in 1906 that the "exceptional size of the corpus callosum may mean exceptional intellectual activity" and claimed differences in size between males and females and between races, although these were refuted by Franklin Mall, the director of his own laboratory. Year 1906 ( MCMVI) was a Common year starting on Monday (link will display full calendar of the Gregorian calendar (or a Common year starting [1]
Of much more substantial popular impact was a 1982 Science article claiming to be the first report of a reliable sex difference in human brain morphology, and arguing for relevance to cognitive gender differences. Year 1982 ( MCMLXXXII) was a Common year starting on Friday (link displays the 1982 Gregorian calendar) Science 80 was a general science magazine published by the American Association for the Advancement of Science (AAAS The term morphology in Biology refers to the outward appearance ( Shape, Structure, Colour, Pattern) of an Organism [2] This paper appears to be the source of a large number of lay explanations of perceived male-female difference in behaviour: For example Time magazine was reported to state in 1992 that the corpus callosum is "Often wider in the brains of women than in those of men, it may allow for greater cross-talk between the hemispheres—possibly the basis for woman’s intuition. For other uses see Time (disambiguation Time is a component of a measuring system used to sequence events to compare the durations of Year 1992 ( MCMXCII) was a Leap year starting on Wednesday (link will display full 1992 Gregorian calendar) "[3] It has also been used, for example, as the explanation of an increased single-task orientation of male, relative to female, learners; a smaller male corpus is said to make it harder for the left and right sides of the brain to work together and to explain a greater feminine ability to multitask.
There is scientific dispute not only about the implications of anatomical difference, but whether such a difference actually exists. A substantial review paper performed a meta-analysis of 49 studies and found, contrary to de Lacoste-Utamsing and Holloway, that males have a larger corpus callosum, a relationship that is true whether or not account is taken of larger male brain size. Ralph Holloway (born 1935 is a Physical anthropologist at Columbia University and research associate with the American Museum of Natural History. [1] Bishop and Wahlstein found that "the widespread belief that women have a larger splenium than men and consequently think differently is untenable. " However, more recent studies using new techniques revealed morphological sex differences in human corpus callosum. [4][5] Whether, and to what extent, these morphological differences are associated with behavioural and cognitive differences between males and females remains unclear.
Other correlations
The corpus callosum has been reported to be significantly larger in musicians than non-musicians,[6] and to be slightly larger in left-handed people than right-handed people. [7]
Epilepsy
The symptoms of refractory epilepsy can be reduced by cutting the corpus callosum in an operation known as a corpus callosotomy. Epilepsy is a common chronic Neurological disorder that is characterized by recurrent unprovoked seizures. Corpus callosotomy (or less frequently callotomy) is a Surgical procedure that disconnects the Cerebral hemispheres resulting in a condition called [8]
Pathology
- Alien hand syndrome
- A complete or partial absence of it in humans is called agenesis of the corpus callosum. Alien hand syndrome ( anarchic hand or Dr Strangelove syndrome) is an unusual Neurological disorder, in which one of the sufferer's hands seems Agenesis of the Corpus Callosum ( ACC) is a rare birth defect ( Congenital disorder) in which there is a complete or partial absence of the Corpus callosum
- Split-brain
- Septo-optic dysplasia (deMorsier syndrome)
External links
Additional images
 Mesal aspect of a brain sectioned in the median sagittal plane. Split-brain is a lay term to describe the result when the Corpus callosum connecting the two hemispheres of the Brain is severed to some degree Septo-optic dysplasia (SOD also known as de Morsier syndrome is a congenital malformation Syndrome manifested by hypoplasia (underdevelopment BrainMaps is an NIH -funded interactive zoomable high-resolution digital brain atlas and virtual microscope that is based on more than 20 million megapixels (50 terabytes |
 Coronal section of brain immediately in front of pons. |
 Coronal section of brain through intermediate mass of third ventricle. |
 Coronal section of lateral and third ventricles. |
 Central part and anterior and posterior cornua of lateral ventricles exposed from above. |
 Coronal section through anterior cornua of lateral ventricles. |
 Coronal section of brain through anterior commissure. |
 Diagram showing the positions of the three principal subarachnoid cisternæ. |
 Medial view of a halved human brain |
References
- ^ a b Bishop KM, Wahlsten D (1997). "Sex differences in the human corpus callosum: myth or reality?". Neurosci Biobehav Rev 21 (5): 581–601. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 9353793.
- ^ de Lacoste-Utamsing, C. , Holloway, R. L. "Sexual dimorphism in the human corpus callosum. " Science, 216, 1431–1432, 1982.
- ^ C Gorman (20 January 1992). "Sizing up the sexes". Time: 36-43.
- ^ Dubb A, Gur R, Avants B, Gee J (2003). "Characterization of sexual dimorphism in the human corpus callosum". Neuroimage 20 (1): 512–9. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 14527611.
- ^ Shin YW, Kim DJ, Ha TH, et al (2005). "Sex differences in the human corpus callosum: diffusion tensor imaging study". Neuroreport 16 (8): 795–8. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 15891572.
- ^ Levitin, Daniel J. "This is Your Brain on Music", '
- ^ Driesen, Naomi R. ; Naftali Raz (1995). "The influence of sex, age, and handedness on corpus callosum morphology: A meta-analysis". Psychobiology 23 (3): 240–247.
- ^ Clarke DF, Wheless JW, Chacon MM, et al (2007). "Corpus callosotomy: a palliative therapeutic technique may help identify resectable epileptogenic foci". Seizure 16 (6): 545–53. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 17521926.
Dictionary
corpus callosum
-noun
- In mammals, a broad band of nerve fibres that connects the left and right hemispheres of the brain.
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