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The ansa lenticularis and ansa fascicularis are two large bundles of fibers that connect the globus pallidus to the thalamus, passing ventral and dorsal to the subthalamic nucleus, respectively.
The ansa lenticularis and ansa fascicularis are two large bundles of fibers that connect the globus pallidus to the thalamus, passing ventral and dorsal to the subthalamic nucleus, respectively.
True (A)
The claustrum, a thin, circular lamina located lateral to the putamen, is well-understood and plays a vital role in motor control.
The claustrum, a thin, circular lamina located lateral to the putamen, is well-understood and plays a vital role in motor control.
False (B)
The internal capsule, located lateral to the thalamus, consists of afferent fibers traveling to the cortex and efferent fibers descending from the cortex.
The internal capsule, located lateral to the thalamus, consists of afferent fibers traveling to the cortex and efferent fibers descending from the cortex.
True (A)
The stria terminalis connects the amygdaloid body to the head of the caudate nucleus within the lateral ventricle's anterior horn.
The stria terminalis connects the amygdaloid body to the head of the caudate nucleus within the lateral ventricle's anterior horn.
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The corpus striatum, comprising the caudate nucleus and the globus pallidus, receives input primarily from the cerebral cortex, thalamus, and substantia nigra.
The corpus striatum, comprising the caudate nucleus and the globus pallidus, receives input primarily from the cerebral cortex, thalamus, and substantia nigra.
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Parkinsonism, a common basal nuclei disease, is characterized by decreased serotonin in the striatonigral pathway, leading to tremor, rigidity, and akinesia.
Parkinsonism, a common basal nuclei disease, is characterized by decreased serotonin in the striatonigral pathway, leading to tremor, rigidity, and akinesia.
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The anterior limb of the internal capsule, situated between the head of the caudate nucleus and the lentiform nucleus, contains corticospinal fibers originating from the motor cortex.
The anterior limb of the internal capsule, situated between the head of the caudate nucleus and the lentiform nucleus, contains corticospinal fibers originating from the motor cortex.
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Projection fibers connect different areas within the same hemisphere, while association fibers join the cortices of the two hemispheres.
Projection fibers connect different areas within the same hemisphere, while association fibers join the cortices of the two hemispheres.
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The subthalamic fasciculus, a component of the basal ganglia circuitry, interconnects the globus pallidus and the subthalamic nucleus, passing through the internal capsule.
The subthalamic fasciculus, a component of the basal ganglia circuitry, interconnects the globus pallidus and the subthalamic nucleus, passing through the internal capsule.
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The corona radiata, a fan-shaped arrangement of fibers, extends from the internal capsule to the cortex, intersecting with fibers of the corpus callosum.
The corona radiata, a fan-shaped arrangement of fibers, extends from the internal capsule to the cortex, intersecting with fibers of the corpus callosum.
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The thalamus, the largest cluster of cells in each cerebral hemisphere, is part of the diencephalon, the core region of the forebrain.
The thalamus, the largest cluster of cells in each cerebral hemisphere, is part of the diencephalon, the core region of the forebrain.
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The basal nuclei, crucial for motor control, are definitively and universally classified as comprising the caudate nucleus, the lentiform nucleus (putamen and globus pallidus), the amygdaloid body, and the claustrum.
The basal nuclei, crucial for motor control, are definitively and universally classified as comprising the caudate nucleus, the lentiform nucleus (putamen and globus pallidus), the amygdaloid body, and the claustrum.
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The corpus striatum, readily identifiable due to its striped appearance, is formed by the interconnected caudate nucleus and globus pallidus.
The corpus striatum, readily identifiable due to its striped appearance, is formed by the interconnected caudate nucleus and globus pallidus.
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The caudate nucleus, resembling a highly curved comma, consists of a head, body, and tail that eventually connects with the lentiform nucleus.
The caudate nucleus, resembling a highly curved comma, consists of a head, body, and tail that eventually connects with the lentiform nucleus.
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The lentiform nucleus, resembling a biconvex lens, includes the putamen and globus pallidus, and encloses the internal capsule.
The lentiform nucleus, resembling a biconvex lens, includes the putamen and globus pallidus, and encloses the internal capsule.
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The putamen, the larger, lateral part of the lentiform nucleus, displays a curved, almost quadrilateral shape.
The putamen, the larger, lateral part of the lentiform nucleus, displays a curved, almost quadrilateral shape.
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The cerebrospinal fluid is found within cavities located in the grey matter of the cerebrum.
The cerebrospinal fluid is found within cavities located in the grey matter of the cerebrum.
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The globus pallidus, part of the lentiform nucleus, is the primary efferent pathway from the corpus striatum.
The globus pallidus, part of the lentiform nucleus, is the primary efferent pathway from the corpus striatum.
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The substantia nigra and subthalamic nucleus, both located within the cerebrum, are consistently included within the classification of basal nuclei due to their integral part in their function.
The substantia nigra and subthalamic nucleus, both located within the cerebrum, are consistently included within the classification of basal nuclei due to their integral part in their function.
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The tail of the caudate nucleus, following the curvature of the structure, joins with the amygdaloid body, a region associated with functions such as memory and behavior.
The tail of the caudate nucleus, following the curvature of the structure, joins with the amygdaloid body, a region associated with functions such as memory and behavior.
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The anterior limb of the internal capsule contains fibers related to the accommodation-convergence reflex, connecting the frontal eye field to the oculomotor nucleus.
The anterior limb of the internal capsule contains fibers related to the accommodation-convergence reflex, connecting the frontal eye field to the oculomotor nucleus.
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The genu of the internal capsule is positioned at the apex of the putamen.
The genu of the internal capsule is positioned at the apex of the putamen.
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Corticospinal fibers, originating from the cerebral cortex and descending to the spinal cord, occupy the anterior two-thirds of the posterior limb of the internal capsule.
Corticospinal fibers, originating from the cerebral cortex and descending to the spinal cord, occupy the anterior two-thirds of the posterior limb of the internal capsule.
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The arrangement of motor fibers within the internal capsule and cerebral peduncle mirrors the body's somatotopic organization, with head fibers positioned anteriorly and perineal fibers laterally.
The arrangement of motor fibers within the internal capsule and cerebral peduncle mirrors the body's somatotopic organization, with head fibers positioned anteriorly and perineal fibers laterally.
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Damage to the right internal capsule results in speech impairment, as Broca's area is typically located in the right hemisphere.
Damage to the right internal capsule results in speech impairment, as Broca's area is typically located in the right hemisphere.
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Thalamocortical fibers, integral to sensory processing, ascend through the corona radiata, a fan-like structure of white matter, en route to the sensory cortex.
Thalamocortical fibers, integral to sensory processing, ascend through the corona radiata, a fan-like structure of white matter, en route to the sensory cortex.
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The sublentiform part of the internal capsule contains the visual radiation, responsible for transmitting visual information to the visual cortex.
The sublentiform part of the internal capsule contains the visual radiation, responsible for transmitting visual information to the visual cortex.
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Comprising approximately 100 million commissural fibers, the corpus callosum facilitates interhemispheric communication, connecting symmetrical cortical regions between the two brain hemispheres.
Comprising approximately 100 million commissural fibers, the corpus callosum facilitates interhemispheric communication, connecting symmetrical cortical regions between the two brain hemispheres.
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The corpus callosum, structurally, originates from the posterior commissure and progresses anteriorly, expanding in thickness along its course.
The corpus callosum, structurally, originates from the posterior commissure and progresses anteriorly, expanding in thickness along its course.
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The fibers within the genu of the corpus callosum, known as the forceps minor, curve forward towards the frontal cortex, creating a distinctive pattern in horizontal brain sections.
The fibers within the genu of the corpus callosum, known as the forceps minor, curve forward towards the frontal cortex, creating a distinctive pattern in horizontal brain sections.
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Flashcards
Cerebrum's Internal Structure
Cerebrum's Internal Structure
The inner part of the cerebrum contains white matter, grey matter masses, and cavities with cerebrospinal fluid.
Thalamus
Thalamus
The largest mass of cells in each brain hemisphere, part of the diencephalon.
Basal Nuclei
Basal Nuclei
Cell groups in the lateral forebrain, previously known as basal ganglia, involved in movement control.
Caudate Nucleus
Caudate Nucleus
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Lentiform Nucleus
Lentiform Nucleus
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Corpus Striatum
Corpus Striatum
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Globus Pallidus
Globus Pallidus
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Amygdaloid Body
Amygdaloid Body
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Substantia Nigra
Substantia Nigra
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Internal Capsule
Internal Capsule
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Putamen
Putamen
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Sublentiform Part
Sublentiform Part
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Retrolentiform Part
Retrolentiform Part
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Cortico-Striato-Pallido-Thalamo-Cortical Pathways
Cortico-Striato-Pallido-Thalamo-Cortical Pathways
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Parkinsonism
Parkinsonism
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Internal Capsule Segments
Internal Capsule Segments
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Corticonuclear Fibres
Corticonuclear Fibres
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Corticospinal Fibres
Corticospinal Fibres
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Genu of Internal Capsule
Genu of Internal Capsule
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Thalamocortical Fibres
Thalamocortical Fibres
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Optic Radiation
Optic Radiation
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Auditory Radiation
Auditory Radiation
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Corpus Callosum
Corpus Callosum
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Lateral Geniculate Body
Lateral Geniculate Body
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Medial Geniculate Body
Medial Geniculate Body
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Study Notes
Cerebrum Internal Structure
- Cerebrum's interior contains masses of gray matter within white matter, and cavities holding cerebrospinal fluid.
- The thalamus, part of the diencephalon, is the largest cell mass in each hemisphere.
- Other cell groups, basal nuclei (basal ganglia), include the caudate nucleus, lentiform nucleus (putamen and globus pallidus), amygdaloid body, and claustrum.
- Basal nuclei classification is inconsistent; the amygdaloid body is often part of the limbic system (due to memory/behavior association), and the substantia nigra and subthalamic nucleus (midbrain), are sometimes included due to connections to the lentiform nucleus.
- Caudate nucleus: comma-shaped with head, body, and tail; forms a "hand holding flowers" shape around the internal capsule; projections into lateral ventricle.
- Lentiform nucleus: biconvex lens shape; buried in the hemisphere; oval outline; two parts: larger putamen (lateral, curved, roughly quadrilateral), smaller globus pallidus (medial, bluntly conical); joined to caudate nucleus head by myelinated/unmyelinated fibers.
- Corpus striatum: collective term for the caudate nucleus and putamen.
- Amygdaloid body: consists of multiple nuclear masses; connected to caudate nucleus tail in inferior horn of lateral ventricle; part of the limbic system.
- Claustrum: thin, circular, saucer-shaped lamina; lateral to putamen; unknown significance.
- Subthalamic nucleus and substantia nigra (midbrain) are other components of basal nuclei considered elsewhere.
Basal Nuclei Function
- Basal nuclei influence skeletal muscle movements (rate, range, coordination).
- Input side is the corpus striatum, receiving fibers from cortex, thalamus, and substantia nigra.
- Output side is the globus pallidus, sending fibers to thalamus, subthalamic nucleus, substantia nigra, and reticular formation.
- Pathways involve various transmitters (acetylcholine, dopamine, glutamate, serotonin, GABA).
- Parkinsonism (tremor, rigidity, akinesia) is a common basal nuclei disease, involving dopamine reduction in the nigrostriatal pathway.
Cerebral White Matter
- Cerebral white matter contains three fiber groups.
- Commissural fibers: connect cortices of both hemispheres; mainly in corpus callosum (also anterior, posterior & habenular commissures).
- Association (arcuate) fibers: confined to one hemisphere; connect different cortical areas.
- Projection fibers: connect hemisphere's gray matter with subcortical nuclei, brainstem, and spinal cord.
Internal Capsule
- Internal capsule: major collection of projection fibers lateral to the thalamus and the head of the caudate nucleus.
- Shaped like a curved fan (corona radiata); both ascending & descending fibers; includes corpus callosum fibers.
- Divided into anterior limb, genu, posterior limb, sublentiform, retrolentiform parts.
- Anterior limb: frontopontine fibers, frontal eye field fibers
- Genu: corticonuclear fibers (cranial nerve motor nuclei)
- Posterior limb: corticospinal fibers (arm, hand, trunk, leg, perineum); Contains corticospinal (main motor fibers), and thalamocortical fibers.
- Retrolentiform and sublentiform parts contain visual and auditory fibers (optic and auditory radiations).
- Important for motor control, speech, and sensory perception; relevant for stroke implications.
Corpus Callosum
- Corpus callosum: large collection (100 million) of commissural fibers; connects symmetrical cortical areas.
- Contains rostrum, genu, body, and splenium; curved in various forms; Fibers extend throughout the cerebral cortex.
- Forceps minor (genu) connects frontal lobes.
- Forceps major (splenium) connects occipital lobes.
- Tapetum is the corpus callosum's extension into inferior and posterior aspects of lateral ventricle.
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Description
Explore the internal structure of the cerebrum, including the arrangement of gray and white matter and the various cell groups such as the thalamus and basal nuclei. Understand the roles of anatomical features like the caudate nucleus and lentiform nucleus within the hemispheres and their connections to other brain regions. This quiz will deepen your comprehension of cerebral anatomy and its functions.
