Brain anatomy - Revision history

Jadrian Miles: /* Commissural Tracts */ cleaned up hippocampal commissure

2014-01-17T19:44:13Z

Commissural Tracts: cleaned up hippocampal commissure

← Older revision		Revision as of 19:44, 17 January 2014
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	: Another smaller band of commissural fibers inferior to the CC and posterior to the anterior commissure.		: Another smaller band of commissural fibers inferior to the CC and posterior to the anterior commissure.
	; Hippocampal commissure (or lyra, or commissue of the fornix)		; Hippocampal commissure (or lyra, or commissue of the fornix)
	: A very small, sheet-shaped band of fibers connecting the two ~~halves (~~hippocampi) of the fornix.		: A very small, sheet-shaped band of fibers connecting the two hippocampi. These connect to, and join the fibers of, the fornix in either hemisphere.

	=== Association Tracts ===		=== Association Tracts ===

Jadrian Miles: /* Association Tracts */ clarified orientation of cingulum

2014-01-17T19:41:28Z

Association Tracts: clarified orientation of cingulum

← Older revision		Revision as of 19:41, 17 January 2014
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	=== Association Tracts ===		=== Association Tracts ===
	; [[/Cingulum bundle\|Cingulum / cingulum bundle]]		; [[/Cingulum bundle\|Cingulum / cingulum bundle]]
	: White matter fibers located just superior to the corpus callosum, but running anterior-posterior. In a para-sagittal section, they look like a letter C turned on its side, with the tips pointing inferior, stacked right on top of the CC. In a coronal section, they look like two small circles just superior to the CC on either side of the interhemispheric fissure.		: White matter fibers located just superior to the corpus callosum, but running anterior-posterior. In a para-sagittal section, they look like a letter C turned on its side, with the tips pointing inferior, stacked right on top of the CC. In a coronal section, they look like two small circles just superior to the CC on either side of the interhemispheric fissure, with fibers running orthogonal to the plane.
	; Fornix		; Fornix
	: C-shaped pathways that surrounds the subcortical gray matter in each hemisphere. It connects the hippocampus to the hypothalamus. Difficult to track due its curvature and partial voluming with gray matter.		: C-shaped pathways that surrounds the subcortical gray matter in each hemisphere. It connects the hippocampus to the hypothalamus. Difficult to track due its curvature and partial voluming with gray matter.

Jadrian Miles: /* Commissural Tracts */ added the other small commissural tracts

2014-01-17T19:40:35Z

Commissural Tracts: added the other small commissural tracts

← Older revision		Revision as of 19:40, 17 January 2014
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	:: A medial projection of the CC (from the body) into the temporal lobe. In a well-reconstructed 3D tractogram, it forms a small horizontal fanning sheet of fibers emanating from the CC.		:: A medial projection of the CC (from the body) into the temporal lobe. In a well-reconstructed 3D tractogram, it forms a small horizontal fanning sheet of fibers emanating from the CC.
	: (Note that the list above is not exhaustive—there are other named tracts that pass through the CC too.)		: (Note that the list above is not exhaustive—there are other named tracts that pass through the CC too.)

			; Anterior commissure
			: A smaller band of fibers that crosses between the hemispheres inferior to the CC.
			; Posterior commissure
			: Another smaller band of commissural fibers inferior to the CC and posterior to the anterior commissure.
			; Hippocampal commissure (or lyra, or commissue of the fornix)
			: A very small, sheet-shaped band of fibers connecting the two halves (hippocampi) of the fornix.

	=== Association Tracts ===		=== Association Tracts ===

Jadrian Miles: /* Commissural Tracts */ clarified about the CC

2014-01-17T19:36:32Z

Commissural Tracts: clarified about the CC

← Older revision		Revision as of 19:36, 17 January 2014
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	=== Commissural Tracts ===		=== Commissural Tracts ===
			The vast majority of commissural tracts cross between the hemispheres in a single localized region called the corpus callosum. Strictly speaking, the corpus callosum is not itself a tract, because it describes only the medial portion of each tract.

	; Corpus callosum (CC)		; Corpus callosum (CC)
	: The large ~~tract~~ of left-right-running fibers connecting the hemispheres. In a mid-sagittal cutting plane, it looks like a letter C turned on its side, with the tips pointing inferior; see [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p8.html]. Though the distal portions of the fibers that make up the CC are grouped into separate tracts in the interior of each hemisphere, they are collectively called the CC where they cross the mid-sagittal plane. In this sense the CC is more of a place name than a tract name; it indicates only the portions of those fibers that are near the mid-sagittal plane. Moving around the CC from the back (posterior), it is subdivided into parts named:		: The large, central collection of left-right-running fibers connecting the hemispheres. In a mid-sagittal cutting plane, it looks like a letter C turned on its side, with the tips pointing inferior (and the fibers running orthogonal to the plane); see the illustration above, or [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p8.html]. Though the distal portions of the fibers that make up the CC are grouped into separate tracts in the interior of each hemisphere, they are collectively called the CC where they cross the mid-sagittal plane. In this sense the CC is more of a place name than a tract name; it indicates only the portions of those fibers that are near the mid-sagittal plane. Moving around the CC from the back (posterior), it is subdivided into parts named:
	:; Splenium		:; Splenium
	:: The posterior, slightly bulbous part of the CC.		:: The posterior, slightly bulbous part of the CC.
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	:; Rostrum		:; Rostrum
	:: The part of the CC inferior and posterior to the genu.		:: The part of the CC inferior and posterior to the genu.
	; Forceps major / forceps posterior		: The fibers that make up the corpus callosum may be grouped into entire tracts, and identified both by their structure and by the region of the CC through which they pass:
	: The posterior projection of the CC (from the splenium) into the occipital lobe (the back of the brain). In an axial section, it looks like a letter C at the posterior portion of the brain with the tips pointing posterior. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].		:; Forceps major / forceps posterior
	; Forceps minor / forceps anterior		:: The posterior projection of the CC (from the splenium) into the occipital lobe (the back of the brain). In an axial section, it looks like a letter C at the posterior portion of the brain with the tips pointing posterior. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].
	: The anterior projection of the CC (from the genu) into the cerebrum (the front of the brain). In an axial section, it looks like a letter C at the anterior portion of the brain with the tips pointing anterior. In other words, it looks sort of like a pair of mandibles over the eyes. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].		:; Forceps minor / forceps anterior
	; Tapetum		:: The anterior projection of the CC (from the genu) into the cerebrum (the front of the brain). In an axial section, it looks like a letter C at the anterior portion of the brain with the tips pointing anterior. In other words, it looks sort of like a pair of mandibles over the eyes. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].
	: A medial projection of the CC (from the body) into the temporal lobe. In a well-reconstructed 3D tractogram, it forms a small horizontal fanning sheet of fibers emanating from the CC.		:; Tapetum
			:: A medial projection of the CC (from the body) into the temporal lobe. In a well-reconstructed 3D tractogram, it forms a small horizontal fanning sheet of fibers emanating from the CC.
			: (Note that the list above is not exhaustive—there are other named tracts that pass through the CC too.)

	=== Association Tracts ===		=== Association Tracts ===

Jadrian Miles: /* Commissural Tracts */ removed dead link to illustration of commissural fibers

2014-01-17T19:24:43Z

Commissural Tracts: removed dead link to illustration of commissural fibers

← Older revision		Revision as of 19:24, 17 January 2014
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	=== Commissural Tracts ===		=== Commissural Tracts ===
	~~See [http://www.debratylermedart.com/medillus_webimages/commisuralfiberswebcopy.jpg] for an illustration of the comissural tracts of the brain.~~

	; Corpus callosum (CC)		; Corpus callosum (CC)
	: The large tract of left-right-running fibers connecting the hemispheres. In a mid-sagittal cutting plane, it looks like a letter C turned on its side, with the tips pointing inferior; see [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p8.html]. Though the distal portions of the fibers that make up the CC are grouped into separate tracts in the interior of each hemisphere, they are collectively called the CC where they cross the mid-sagittal plane. In this sense the CC is more of a place name than a tract name; it indicates only the portions of those fibers that are near the mid-sagittal plane. Moving around the CC from the back (posterior), it is subdivided into parts named:		: The large tract of left-right-running fibers connecting the hemispheres. In a mid-sagittal cutting plane, it looks like a letter C turned on its side, with the tips pointing inferior; see [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p8.html]. Though the distal portions of the fibers that make up the CC are grouped into separate tracts in the interior of each hemisphere, they are collectively called the CC where they cross the mid-sagittal plane. In this sense the CC is more of a place name than a tract name; it indicates only the portions of those fibers that are near the mid-sagittal plane. Moving around the CC from the back (posterior), it is subdivided into parts named:

Ryan Cabeen at 18:36, 6 July 2013

2013-07-06T18:36:00Z

← Older revision		Revision as of 18:36, 6 July 2013
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	: White matter fibers located just superior to the corpus callosum, but running anterior-posterior. In a para-sagittal section, they look like a letter C turned on its side, with the tips pointing inferior, stacked right on top of the CC. In a coronal section, they look like two small circles just superior to the CC on either side of the interhemispheric fissure.		: White matter fibers located just superior to the corpus callosum, but running anterior-posterior. In a para-sagittal section, they look like a letter C turned on its side, with the tips pointing inferior, stacked right on top of the CC. In a coronal section, they look like two small circles just superior to the CC on either side of the interhemispheric fissure.
	; Fornix		; Fornix
	: ~~???~~		: C-shaped pathways that surrounds the subcortical gray matter in each hemisphere. It connects the hippocampus to the hypothalamus. Difficult to track due its curvature and partial voluming with gray matter.
	; Inferior longitudinal fasciculus (ILF)		; Inferior longitudinal fasciculus (ILF)
	: ~~???~~		: A pathway that runs from the occipital to temporal cortices in each hemisphere. The majority of the fibers are in the temporal lobe.
	; Superior longitudinal fasciculus (SLF)		; Superior longitudinal fasciculus (SLF)
	: ~~???~~		: A collection of pathways that run between the frontal lobe and the temporal, parietal, and occipital lobes in each hemisphere. There are several subdivisions typically made based on their posterior connections.
	:; SLF I		:; SLF I
	:: ~~???~~		:: The portion of the SLF that intersects the corpus callosum and connects superior frontal cortex to parietal and occipital cortex. Typically not reconstructed with the single tensor model.
	:; SLF II		:; SLF II
	:: ~~???~~		:: The portion of the SLF that connects lateral frontal white matter (such as DLPFC) to the parietal and occipital cortices. Sometimes reconstructed with single tensors.
	:; SLF III		:; SLF III
	:: ~~???~~		:: The portion superior to the arcuate that connects lateral-inferior frontal cortex to parietal cortex. These fibers are very similar to the arcuate but do not curve.
	:; Arcuate fasciculus (AF)		:; Arcuate fasciculus (AF)
	:: ~~???~~		:: The portion of the SLF that curves to connect frontal cortex to the temporal lobe.
	; Uncinate fasciculus		; Uncinate fasciculus
	: ~~???~~		: A pathway that connects inferior frontal cortex to the temporal pole in each hemisphere. This curves around the insula cortex. Sometimes difficult to track due to high curvature.

	=== Projection Tracts ===		=== Projection Tracts ===

Jadrian Miles: /* Commissural Tracts */

2009-12-08T16:41:08Z

Commissural Tracts

← Older revision		Revision as of 16:41, 8 December 2009
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	:: The part of the CC inferior and posterior to the genu.		:: The part of the CC inferior and posterior to the genu.
	; Forceps major / forceps posterior		; Forceps major / forceps posterior
	: The posterior projection of the CC (from the splenium) into the occipital lobe (the back of the brain). In ~~a transverse~~ section, it looks like a letter C at the posterior portion of the brain with the tips pointing posterior. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].		: The posterior projection of the CC (from the splenium) into the occipital lobe (the back of the brain). In an axial section, it looks like a letter C at the posterior portion of the brain with the tips pointing posterior. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].
	; Forceps minor / forceps anterior		; Forceps minor / forceps anterior
	: The anterior projection of the CC (from the genu) into the cerebrum (the front of the brain). In ~~a transverse~~ section, it looks like a letter C at the anterior portion of the brain with the tips pointing anterior. In other words, it looks sort of like a pair of mandibles over the eyes. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].		: The anterior projection of the CC (from the genu) into the cerebrum (the front of the brain). In an axial section, it looks like a letter C at the anterior portion of the brain with the tips pointing anterior. In other words, it looks sort of like a pair of mandibles over the eyes. See [http://anatomy.uams.edu/anatomyhtml/atlas_html/n1a5p7.html].
	; Tapetum		; Tapetum
	: ~~The~~ medial projection of the CC (from the body) into the temporal lobe. In a well-reconstructed 3D tractogram, it forms a fanning sheet of fibers emanating from the CC.		: A medial projection of the CC (from the body) into the temporal lobe. In a well-reconstructed 3D tractogram, it forms a small horizontal fanning sheet of fibers emanating from the CC.

	=== Association Tracts ===		=== Association Tracts ===

Jadrian Miles: /* Grey Matter Structures */

2009-12-05T00:13:04Z

Grey Matter Structures

← Older revision		Revision as of 00:13, 5 December 2009
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	== Grey Matter Structures ==		== Grey Matter Structures ==
	; Thalamus		; Thalamus
	: Major relay nuclei (~~a gray~~ matter ~~structure~~) in the diencephalon (division of the brain primarily containing thalamus and hypothalamus in mature brain). Most sensory information is carried to the thalamus first (i.e., via ascending tracts) and then relayed to the cerebral cortex. Similarly, neural signals controlling movements, learning, memory and emotions bound to sub-cortical structures are relayed by the thalamus to their final destinations.		: Major relay nuclei (grey matter structures) in the diencephalon (division of the brain primarily containing thalamus and hypothalamus in mature brain). Most sensory information is carried to the thalamus first (i.e., via ascending tracts) and then relayed to the cerebral cortex. Similarly, neural signals controlling movements, learning, memory and emotions bound to sub-cortical structures are relayed by the thalamus to their final destinations.
	; [[w:Hippocampus\|Hippocampus]]		; [[w:Hippocampus\|Hippocampus]]
	: Paired horn-shaped structures beneath the medial surface of the temporal lobes. Each half of the hippocampus is an elaboration of the edge of the cerebral cortex, where it folds up and inward from the inferior surface of the temporal lobe and curls around on itself. The hippocampus is associated with spatial memory.		: Paired horn-shaped structures beneath the medial surface of the temporal lobes. Each half of the hippocampus is an elaboration of the edge of the cerebral cortex, where it folds up and inward from the inferior surface of the temporal lobe and curls around on itself. The hippocampus is associated with spatial memory.

Jadrian Miles: /* External Links */

2009-12-04T18:41:46Z

External Links

← Older revision		Revision as of 18:41, 4 December 2009
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	* [http://radiopaedia.org/encyclopaedia/anatomy/central-nervous-system Radiopaedia] --- a wiki encyclopedia for radiology; search for articles		* [http://radiopaedia.org/encyclopaedia/anatomy/central-nervous-system Radiopaedia] --- a wiki encyclopedia for radiology; search for articles
	* [http://www.bartleby.com/107/index.html#chap10 Gray's Anatomy] --- an illustrated anatomy textbook from 1918		* [http://www.bartleby.com/107/index.html#chap10 Gray's Anatomy] --- an illustrated anatomy textbook from 1918
	* [[https://www.mristudio.org MRI Studio]] is a program that supposedly includes [[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2478641 Mori, et al.'s 2008 multi-subject DTI-based WM atlas]]		* [https://www.mristudio.org MRI Studio] is a program that supposedly includes [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2478641 Mori, et al.'s 2008 multi-subject DTI-based WM atlas]

	[[Category:Diffusion MRI]]		[[Category:Diffusion MRI]]

Jadrian Miles: /* External Links */

2009-12-04T18:41:34Z

External Links

← Older revision		Revision as of 18:41, 4 December 2009
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	* [http://radiopaedia.org/encyclopaedia/anatomy/central-nervous-system Radiopaedia] --- a wiki encyclopedia for radiology; search for articles		* [http://radiopaedia.org/encyclopaedia/anatomy/central-nervous-system Radiopaedia] --- a wiki encyclopedia for radiology; search for articles
	* [http://www.bartleby.com/107/index.html#chap10 Gray's Anatomy] --- an illustrated anatomy textbook from 1918		* [http://www.bartleby.com/107/index.html#chap10 Gray's Anatomy] --- an illustrated anatomy textbook from 1918
			* [[https://www.mristudio.org MRI Studio]] is a program that supposedly includes [[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2478641 Mori, et al.'s 2008 multi-subject DTI-based WM atlas]]

	[[Category:Diffusion MRI]]		[[Category:Diffusion MRI]]