Lateral ventricles | |
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![]() 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 |
NeuroLex ID | birnlex_1263 |
TA98 | A14.1.09.272 |
TA2 | 5639 |
FMA | 78448 |
Anatomical terms of neuroanatomy |
The lateral ventricles are the two largest ventricles of the brain and contain cerebrospinal fluid. [1] Each cerebral hemisphere contains a lateral ventricle, known as the left or right lateral ventricle, respectively.
Each lateral ventricle resembles a C-shaped cavity that begins at an inferior horn in the temporal lobe, travels through a body in the parietal lobe and frontal lobe, and ultimately terminates at the interventricular foramina where each lateral ventricle connects to the single, central third ventricle. Along the path, a posterior horn extends backward into the occipital lobe, and an anterior horn extends farther into the frontal lobe. [1]
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 the trigone of the lateral ventricle. The centre of the superior curve is referred to as the body, while the three remaining portions are known as horns (cornua in Latin); they are usually referred to by their position relative to the body (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 are neuroepithelial cells, line the ventricular system including the lateral ventricles. [1] [2]
Between the inferior horn and the main body of the ventricle is the putamen, which emerges from the head of the caudate 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 the globus pallidus, with which it connects. These structures bounding the lateral ventricles form a frame curving around the thalamus, which itself constitutes the main structure bounding the third ventricle. Were it not for the choroid plexus, a cleft-like opening would be all that lay between the lateral ventricle and the thalamus; this cleft constitutes the lower part of the choroid fissure. The thalamus primarily communicates with the structures bounding the lateral ventricles via the globus pallidus, and the anterior extremities of the fornix (the mamillary bodies). [1]
The anterior horn of the lateral ventricle is also known as the frontal horn as it extends into the frontal lobe. The anterior horn connects to the third ventricle, via the interventricular 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 the corpus callosum - the floor at the limit of the ventricle is the upper surface of the rostrum (the reflected portion of the corpus callosum), while nearer the body of the ventricle, the roof consists of the posterior surface of the genu . The remaining boundary - that facing interior to the ventricle curvature - comprises the posterior edge of the caudate nucleus. [1] Frontal horn cysts are sometimes found on the frontal horn as a normal variant. [3]
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 the tapetum of the corpus callosum - and is separated medially from the other lateral ventricle by the septum 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 narrow stria terminalis, which sits upon the superior thalamostriate vein. The main part of the fornix of the brain forms the next narrow portion of the lateral boundary, which is completed medially by a choroid plexus, which serves both ventricles.
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 the atrium of the lateral ventricle, and is where the choroid plexus is enlarged as the choroid glomus. As a triangular surface feature of the floor of this part of the lateral ventricle it is known as the collateral trigone. [4] [5]
The posterior horn of lateral ventricle, or occipital horn, impinges into the occipital lobe in a posterior direction, initially laterally but subsequently curving medially and lilting inferiorly on the lateral side. The tapetum of the corpus callosum continues 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 as forceps (due to the resulting shape), to curve around the central sulci; the edge of these forceps form the upper part of the medial side of the posterior horn. The remainder of the medial edge of the ventricle is directly in contact with white matter of the cortex of the occipital lobe.
The inferior horn of the lateral ventricle, or temporal 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 the fimbria hippocampi (from which the fornix emerges), and then, more anteriorly, by the hippocampus itself. [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]
The 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 of prenatal 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 produce cerebrospinal 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 the obex (in the caudal medulla), to become the central canal of the spinal 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:
Fetal lateral ventricles may be diagnosed using linear or planar measurements. [7]
The volume of the lateral ventricles is enlarged in some neurological diseases, such as schizophrenia, [8] bipolar disorder, [9] major depressive disorder, [9] and Alzheimer's disease. [10]
Asymmetry as an anatomical variation, in the size of the lateral ventricles is found in about 5–12% of the population. This has been associated with handedness, 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. [11] A severe asymmetry, or an asymmetry with midline shift or diffuse enlargement, may indicate brain injury early in life, particularly in cases of a longer right posterior horn. [11]
Articles related to anatomy include:
The brainstem is the stalk-like part of the brain that interconnects the cerebrum and diencephalon with the spinal cord. In the human brain, the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch.
In neuroanatomy, the ventricular system is a set of four interconnected cavities known as cerebral ventricles in the brain. Within each ventricle is a region of choroid plexus which produces the circulating cerebrospinal fluid (CSF). The ventricular system is continuous with the central canal of the spinal cord from the fourth ventricle, allowing for the flow of CSF to circulate.
The vertebrate cerebrum (brain) is formed by two cerebral hemispheres that are separated by a groove, the longitudinal fissure. The brain can thus be described as being divided into left and right cerebral hemispheres. Each of these hemispheres has an outer layer of grey matter, the cerebral cortex, that is supported by an inner layer of white matter. In eutherian (placental) mammals, the hemispheres are linked by the corpus callosum, a very large bundle of nerve fibers. Smaller commissures, including the anterior commissure, the posterior commissure and the fornix, also join the hemispheres and these are also present in other vertebrates. These commissures transfer information between the two hemispheres to coordinate localized functions.
The cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe.
The third ventricle is one of the four connected cerebral ventricles of the ventricular system within the mammalian brain. It is a slit-like cavity formed in the diencephalon between the two thalami, in the midline between the right and left lateral ventricles, and is filled with cerebrospinal fluid (CSF).
The fornix is a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. The fornix also carries some afferent fibers to the hippocampus from structures in the diencephalon and basal forebrain. The fornix is part of the limbic system. While its exact function and importance in the physiology of the brain are still not entirely clear, it has been demonstrated in humans that surgical transection—the cutting of the fornix along its body—can cause memory loss. There is some debate over what type of memory is affected by this damage, but it has been found to most closely correlate with recall memory rather than recognition memory. This means that damage to the fornix can cause difficulty in recalling long-term information such as details of past events, but it has little effect on the ability to recognize objects or familiar situations.
The internal capsule is a white matter structure situated in the inferomedial part of each cerebral hemisphere of the brain. It carries information past the basal ganglia, separating the caudate nucleus and the thalamus from the putamen and the globus pallidus. The internal capsule contains both ascending and descending axons, going to and coming from the cerebral cortex. It also separates the caudate nucleus and the putamen in the dorsal striatum, a brain region involved in motor and reward pathways.
The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ventricle. The fourth ventricle extends from the cerebral aqueduct to the obex, and is filled with cerebrospinal fluid (CSF).
In the brain, the interventricular foramina are channels that connect the paired lateral ventricles with the third ventricle at the midline of the brain. As channels, they allow cerebrospinal fluid (CSF) produced in the lateral ventricles to reach the third ventricle and then the rest of the brain's ventricular system. The walls of the interventricular foramina also contain choroid plexus, a specialized CSF-producing structure, that is continuous with that of the lateral and third ventricles above and below it.
The lentiform nucleus are the putamen (laterally) and the globus pallidus (medially), collectively. Due to their proximity, these two structures were formerly considered one, however, the two are separated by a thin layer of white matter - the external medullary lamina - and are functionally and connectionally distinct.
The lobes of the brain are the major identifiable zones of the human cerebral cortex, and they comprise the surface of each hemisphere of the cerebrum. The two hemispheres are roughly symmetrical in structure, and are connected by the corpus callosum. They traditionally have been divided into four lobes, but are today considered as having six lobes each. The lobes are large areas that are anatomically distinguishable, and are also functionally distinct to some degree. Each lobe of the brain has numerous ridges, or gyri, and furrows, the sulci that constitute further subzones of the cortex. The expression "lobes of the brain" usually refers only to those of the cerebrum, not to the distinct areas of the cerebellum.
The anterior choroidal artery is a bilaterally paired artery of the brain. It is typically a branch of the internal carotid artery which supplies the choroid plexus of lateral ventricle and third ventricle as well as numerous structures of the brain.
The posterior cerebral artery (PCA) is one of a pair of cerebral arteries that supply oxygenated blood to the occipital lobe, part of the back of the human brain. The two arteries originate from the distal end of the basilar artery, where it bifurcates into the left and right posterior cerebral arteries. These anastomose with the middle cerebral arteries and internal carotid arteries via the posterior communicating arteries.
The rhomboid fossa is a rhombus-shaped depression that is the anterior part of the fourth ventricle. Its anterior wall, formed by the back of the pons and the medulla oblongata, constitutes the floor of the fourth ventricle.
The tela choroidea is a region of meningeal pia mater that adheres to the underlying ependyma, and gives rise to the choroid plexus in each of the brain’s four ventricles. Tela is Latin for woven and is used to describe a web-like membrane or layer. The tela choroidea is a very thin part of the loose connective tissue of pia mater overlying and closely adhering to the ependyma. It has a rich blood supply. The ependyma and vascular pia mater – the tela choroidea, form regions of minute projections known as a choroid plexus that projects into each ventricle. The choroid plexus produces most of the cerebrospinal fluid of the central nervous system that circulates through the ventricles of the brain, the central canal of the spinal cord, and the subarachnoid space. The tela choroidea in the ventricles forms from different parts of the roof plate in the development of the embryo.
The cave of septum pellucidum (CSP), cavum septi pellucidi, or cavity of septum pellucidum is a slit-like space in the septum pellucidum that is present in fetuses but usually fuses during infancy. The septum pellucidum is a thin, laminated translucent vertical membrane in the midline of the brain separating the anterior horns of the right and left ventricles. It lies posterior to the corpus callosum. Persistence of the cave of septum pellucidum after infancy has been loosely associated with neural maldevelopment and several mental disorders that correlate with decreased brain tissue.
The trisynaptic circuit or trisynaptic loop is a relay of synaptic transmission in the hippocampus. The circuit was initially described by the neuroanatomist Santiago Ramon y Cajal, in the early twentieth century, using the Golgi staining method. After the discovery of the trisynaptic circuit, a series of research has been conducted to determine the mechanisms driving this circuit. Today, research is focused on how this loop interacts with other parts of the brain, and how it influences human physiology and behaviour. For example, it has been shown that disruptions within the trisynaptic circuit lead to behavioural changes in rodent and feline models.
The choroid veins are the superior choroid vein, and the inferior choroid vein of the lateral ventricle. Both veins drain different parts of the choroid plexus.