Thelateral ventriclesare the two largestventriclesof thebrainand containcerebrospinal fluid.[1]Eachcerebral hemispherecontains a lateral ventricle, known as the left or right lateral ventricle, respectively.
| Lateral ventricles | |
|---|---|
 Scheme showing relations of the ventricles to the surface of the brain; oriented facing left. | |
 Drawing of a cast of the ventricular cavities, viewed from the side; oriented facing right. | |
| Details | |
| Identifiers | |
| Latin | ventriculus lateralis |
| MeSH | D020547 |
| NeuroNames | 209 |
| NeuroLexID | birnlex_1263 |
| TA98 | A14.1.09.272 |
| TA2 | 5639 |
| FMA | 78448 |
| Anatomical terms of neuroanatomy | |
Each lateral ventricle resembles a C-shaped cavity that begins at an inferior horn in thetemporal lobe,travels through a body in theparietal lobeandfrontal lobe,and ultimately terminates at theinterventricular foraminawhere each lateral ventricle connects to the single, centralthird ventricle.Along the path, a posterior horn extends backward into theoccipital lobe,and ananterior hornextends farther into the frontal lobe.[1]
Structure
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Each lateral ventricle takes the form of an elongated curve, with an additional anterior-facing continuation emerging inferiorly from a point near the posterior end of the curve; the junction is known as thetrigone of the lateral ventricle.The centre of the superior curve is referred to as thebody,while the three remaining portions are known ashorns(cornuain Latin); they are usually referred to by their position relative to thebody(anterior, posterior, or inferior), or sometimes by the lobe of the cerebral cortex into which they extend. Though somewhat flat, the lateral ventricles have a vaguely triangular cross-section.Ependyma,which areneuroepithelial cells,line the ventricular system including the lateral ventricles.[1][2]
Between the inferior horn and the main body of the ventricle is theputamen,which emerges from the head of thecaudate nucleus,and sits above the tapetum; a small number of further connections passing through the occipital tapetum to join the putamen to portions of the caudate nucleus tail adjoining the anterior horn. Below the putamen sits theglobus pallidus,with which it connects. These structures bounding the lateral ventricles form a frame curving around thethalamus,which itself constitutes the main structure bounding the third ventricle. Were it not for thechoroid plexus,a cleft-like opening would be all that lay between the lateral ventricle and the thalamus; this cleft constitutes the lower part of thechoroid fissure.The thalamus primarily communicates with the structures bounding the lateral ventricles via the globus pallidus, and the anterior extremities of the fornix (themamillary bodies).[1]
Anterior horns of the lateral ventricle
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The anterior horn of the lateral ventricle is also known as thefrontal hornas it extends into thefrontal lobe.The anterior horn connects to thethird ventricle,via theinterventricular foramen.[1]This portion of the lateral ventricle impinges on the frontal lobe, passing anteriorly and laterally, with slight inclination inferiorly. It is separated from the anterior horn of the other lateral ventricle by a thin neural sheet -septum pellucidum,which thus forms its medial boundary. The boundary facing exterior to the ventricle curvature is formed by thecorpus callosum- thefloorat the limit of the ventricle is the upper surface of therostrum(the reflected portion of the corpus callosum), while nearer thebodyof the ventricle, theroofconsists of the posterior surface of thegenu.The remaining boundary - that facing interior to the ventricle curvature - comprises the posterior edge of thecaudate nucleus.[1]Frontal horn cystsare sometimes found on the frontal horn as a normal variant.[3]
Body of the lateral ventricle
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The body of the lateral ventricle, or central part is the part of the ventricle between the anterior horn and the trigone. Its roof is bound by thetapetum of the corpus callosum- and is separated medially from the other lateral ventricle by theseptum pellucidum.The tail of the caudate nucleus forms the upper portion of the lateral edge, but it is not large enough to cover the whole boundary. Immediately below the tail of the caudate nucleus, the next portion of the lateral edge is formed by the comparatively narrowstria terminalis,which sits upon thesuperior thalamostriate vein.The main part of thefornix of the brainforms the next narrow portion of the lateral boundary, which is completed medially by achoroid plexus,which serves both ventricles.
Trigone of the lateral ventricle
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The trigone of the lateral ventricle is the area where the part of the body forms a junction with the inferior horn and the posterior horn. This area is referred to as theatriumof the lateral ventricle, and is where the choroid plexus is enlarged as thechoroid glomus.As a triangular surface feature of the floor of this part of the lateral ventricle it is known as thecollateral trigone.[4][5]
Posterior horn of the lateral ventricle
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The posterior horn of lateral ventricle, oroccipital horn,impinges into theoccipital lobein a posterior direction, initially laterally but subsequently curving medially and lilting inferiorly on the lateral side. The tapetum of thecorpus callosumcontinues to form the roof, which due to the lilt is also the lateral edge. However, the posterior and anterior ends of the corpus callosum are characterized by tighter bundling, known asforceps(due to the resulting shape), to curve around the central sulci; the edge of theseforcepsform the upper part of the medial side of the posterior horn. The remainder of the medial edge of the ventricle is directly in contact withwhite matterof the cortex of the occipital lobe.
Inferior horn of the lateral ventricle
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The inferior horn of the lateral ventricle, ortemporal horn,is the largest of the horns.[1]It extends anteriorly from the atrium beneath the thalamus and terminates at the amygdala.[1]The collateral eminence and hippocampus form the floor, which is separated from the hippocampus by a white matter layer called the alveus, whereas the roof is formed by the thalamus, the caudate nucleus, and tapetum.[1]The stria terminalis forms the remainder of the roof, which is narrower than at the body, and the choroid plexus occupies the medial wall.[1]
The tapetum for the temporal lobe comprises the lateral boundary of the inferior horn, on its way to join the main tapetum above the body of the ventricle (passing over the caudate nucleus as it does so). The majority of the inferior horn's floor is formed by thefimbria hippocampi(from which the fornix emerges), and then, more anteriorly, by thehippocampusitself.[1]As with the posterior horn, the remainder of the boundary (in this case, the lateral side of the floor) is directly in contact with the white matter of the surrounding lobe.[1]
Development
editThe lateral ventricles, similarly to other parts of the ventricular system of the brain, develop from the central canal of the neural tube.[1]Specifically, the lateral ventricles originate from the portion of the tube that is present in the developing prosencephalon, and subsequently in the developing telencephalon.
During the first three months ofprenatal development,the central canal expands into lateral, third, and fourth ventricles, connected by thinner channels.[6]In the lateral ventricles, specialized areas – choroid plexuses – appear, which producecerebrospinal fluid.The neural canal that does not expand and remains the same at the level of the midbrain superior to the fourth ventricle forms the cerebral aqueduct. The fourth ventricle narrows at theobex(in the caudal medulla), to become thecentral canalof thespinal cord.
During development, pressure from exterior structures causes a number of concave bulges to form within the lateral ventricles, which can be extremely variable in their degree of development; in some individuals they are ill-defined, while in others they can be prominent:
- from theforcepsagainst the posterior horn - creating thebulb of the posterior cornuon the upper medial side of the horn
- from thecalcarine sulcusagainst the posterior horn - creating thecalcar avis(historically called thehippocampus minor,for visual reasons) on the lower medial side of the horn
- from the hippocampus against the inferior horn (on the medial floor of the horn)
- from thecollateral sulcusagainst the inferior horn - creating thecollateral eminenceon the lateral floor of the horn.
Fetal lateral ventricles may be diagnosed using linear or planar measurements.[7]
Clinical significance
editThe volume of the lateral ventricles is enlarged in some neurological diseases, such asschizophrenia,[8]bipolar disorder,[9]major depressive disorder,[9]andAlzheimer's disease.[10]
Ventriculomegalyis a brain condition that mainly occurs during development when the lateral ventricles become dilated.[11]
Asymmetry as ananatomical variation,in the size of the lateral ventricles is found in about 5–12% of the population. This has been associated withhandedness,where right-handed people have been found to have a larger right lateral ventricle and a longer left posterior horn, whereas left-handed people have been found to have longer right posterior horns.[12]A severe asymmetry, or an asymmetry withmidline shiftor diffuse enlargement, may indicatebrain injuryearly in life, particularly in cases of a longer right posterior horn.[12]
Additional images
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Position of lateral ventricles (shown in red) -
Drawing of a cast of the ventricular cavities, viewed from above
See also
editReferences
edit- ^abcdefghijklmScelsi CL, Rahim TA, Morris JA, Kramer GJ, Gilbert BC, Forseen SE (April 2020)."The Lateral Ventricles: A Detailed Review of Anatomy, Development, and Anatomic Variations".American Journal of Neuroradiology.41(4): 566–572.doi:10.3174/ajnr.A6456.PMC7144651.PMID32079598.
- ^Crossman, A R (2005).Neuroanatomy.Elsevier. p. 32.ISBN978-0-443-10036-9.
- ^Unger, S; Salem, S; Wylie, L; Shah, V (February 2011). "Newborn frontal horn cysts: cause for concern?".Journal of Perinatology.31(2): 98–103.doi:10.1038/jp.2010.79.PMID20616785.S2CID9691516.
- ^Marsh, Phillip."Trigone of the lateral ventricle | Radiology Reference Article | Radiopaedia.org".Radiopaedia.
- ^"BrainInfo".braininfo.rprc.washington.edu.
- ^Carlson, Bruce M. (1999).Human Embryology & Developmental Biology.Mosby. pp. 237–238.ISBN0-8151-1458-3.
- ^Glonek, M; Kedzia, A; Derkowski, W (2003). "Planar measurements of foetal lateral ventricles".Folia Morphologica.62(3): 263–5.PMID14507062.
- ^Wright IC, Rabe-Hesketh S, Woodruff PW, David AS, Murray RM, Bullmore ET (January 2000)."Meta-analysis of regional brain volumes in schizophrenia".Am J Psychiatry.157(1): 16–25.doi:10.1176/ajp.157.1.16.PMID10618008.
- ^abKempton, Matthew J.; Geddes, John R.; Ettinger, Ulrich; Williams, Steven C. R.; Grasby, Paul M. (2008-09-01). "Meta-analysis, Database, and Meta-regression of 98 Structural Imaging Studies in Bipolar Disorder".Archives of General Psychiatry.65(9): 1017.doi:10.1001/archpsyc.65.9.1017.ISSN0003-990X.
- ^Nestor, S; Rupsingh, R; Borrie, M; Smith, M; Accomazzi, V; Wells, J; Fogarty, J; Bartha, R (2008)."Ventricular Enlargement as a Surrogate Marker of Alzheimer Disease Progression Validated Using ADNI".Brain.131(9): 2443–2454.doi:10.1093/brain/awn146.PMC2724905.PMID18669512.
- ^Glonek, Michał; Kedzia, Alicja; Derkowski, Wojciech (2003)."Prenatal assessment of ventriculomegaly: an anatomical study".Medical Science Monitor: International Medical Journal of Experimental and Clinical Research.9(7): MT69–77.ISSN1234-1010.PMID12883459.
- ^abMortazavi, M. M.; Adeeb, N.; Griessenauer, C. J.; Sheikh, H.; Shahidi, S.; Tubbs, R. I.; Tubbs, R. S. (2013). "The ventricular system of the brain: a comprehensive review of its history, anatomy, histology, embryology, and surgical considerations".Child's Nervous System.30(1): 19–35.doi:10.1007/s00381-013-2321-3.ISSN0256-7040.PMID24240520.S2CID13815435.
