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Questions and Answers
The thalamus, the largest cell mass in each cerebral hemisphere, is part of the cerebrum's lateral section.
The thalamus, the largest cell mass in each cerebral hemisphere, is part of the cerebrum's lateral section.
False (B)
The basal nuclei are universally acknowledged to consist of the caudate nucleus, lentiform nucleus, amygdaloid body, and claustrum.
The basal nuclei are universally acknowledged to consist of the caudate nucleus, lentiform nucleus, amygdaloid body, and claustrum.
False (B)
The corpus striatum derives its striated appearance from the interconnecting fibers of the caudate nucleus and putamen.
The corpus striatum derives its striated appearance from the interconnecting fibers of the caudate nucleus and putamen.
True (A)
The globus pallidus transmits the central efferent pathway from the corpus striatum.
The globus pallidus transmits the central efferent pathway from the corpus striatum.
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The head of the caudate nucleus connects directly to the amygdaloid body.
The head of the caudate nucleus connects directly to the amygdaloid body.
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The caudate nucleus encircles the internal capsule, resembling a hand grasping a bouquet.
The caudate nucleus encircles the internal capsule, resembling a hand grasping a bouquet.
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The lentiform nucleus is a prominently visible structure on the surface of the cerebral hemisphere.
The lentiform nucleus is a prominently visible structure on the surface of the cerebral hemisphere.
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The putamen is situated medially to the globus pallidus within the lentiform nucleus.
The putamen is situated medially to the globus pallidus within the lentiform nucleus.
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The claustrum and globus pallidus are both conical in shape.
The claustrum and globus pallidus are both conical in shape.
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Cerebrospinal fluid can be found within the white matter of the cerebrum.
Cerebrospinal fluid can be found within the white matter of the cerebrum.
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The anterior limb of the internal capsule contains fibers associated with the accommodation-convergence reflex, connecting the frontal eye field to the oculomotor nucleus.
The anterior limb of the internal capsule contains fibers associated with the accommodation-convergence reflex, connecting the frontal eye field to the oculomotor nucleus.
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Corticospinal fibers, originating from the cerebral cortex and descending to the lower medulla, primarily decussate to form the anterior corticospinal tract.
Corticospinal fibers, originating from the cerebral cortex and descending to the lower medulla, primarily decussate to form the anterior corticospinal tract.
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Within the internal capsule, the arrangement of motor fibers is such that those controlling the arm are positioned anterior to those controlling the leg.
Within the internal capsule, the arrangement of motor fibers is such that those controlling the arm are positioned anterior to those controlling the leg.
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The genu of the internal capsule is located at the apex of the putamen.
The genu of the internal capsule is located at the apex of the putamen.
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The retrolentiform part of the internal capsule houses auditory fibers, while the sublentiform part contains visual fibers.
The retrolentiform part of the internal capsule houses auditory fibers, while the sublentiform part contains visual fibers.
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The corpus callosum, a significant structure containing about 100 million commissural fibers, facilitates interhemispheric communication.
The corpus callosum, a significant structure containing about 100 million commissural fibers, facilitates interhemispheric communication.
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The corticospinal fibers within the internal capsule are arranged with those for the perineum located anterior to those for the hand.
The corticospinal fibers within the internal capsule are arranged with those for the perineum located anterior to those for the hand.
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Lesions in the left internal capsule can result in hemiplegia on the left side of the body accompanied by speech impairment.
Lesions in the left internal capsule can result in hemiplegia on the left side of the body accompanied by speech impairment.
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Thalamocortical fibers, carrying sensory information from the ipsilateral side of the body, ascend through the corona radiata to the sensory cortex.
Thalamocortical fibers, carrying sensory information from the ipsilateral side of the body, ascend through the corona radiata to the sensory cortex.
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The fibers of the corpus callosum's genu, known as the forceps minor, project forward to the frontal cortex.
The fibers of the corpus callosum's genu, known as the forceps minor, project forward to the frontal cortex.
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Flashcards
Cerebrum structure
Cerebrum structure
The cerebrum has both grey and white matter with fluid cavities.
Thalamus
Thalamus
The thalamus is the largest mass of cells in each hemisphere of the cerebrum.
Basal nuclei
Basal nuclei
Groups of nerve cells involved in movement control, traditionally known as basal ganglia.
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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Internal capsule
Internal capsule
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Substantia nigra
Substantia nigra
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Putamen
Putamen
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Subthalamic Nucleus
Subthalamic Nucleus
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Ansa Fascicularis
Ansa Fascicularis
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Projection Fibers
Projection Fibers
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Parkinsonism
Parkinsonism
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Cerebral peduncle
Cerebral peduncle
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Corticospinal fibers
Corticospinal fibers
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Corticonuclear fibers
Corticonuclear fibers
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Thalamocortical fibers
Thalamocortical fibers
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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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Genu of internal capsule
Genu of internal capsule
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Hemiplegia
Hemiplegia
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Study Notes
Cerebrum Internal Structure
- Cerebrum's interior contains masses of grey matter within white matter and cavities holding cerebrospinal fluid.
- Thalamus, the largest cell mass in each hemisphere, is part of the diencephalon (forebrain).
- Basal nuclei (basal ganglia) are grouped in the forebrain's lateral regions.
- Including: caudate nucleus, lentiform nucleus (putamen and globus pallidus), amygdaloid body, and claustrum.
- Amygdaloid body is often classified as part of the limbic system due to its role in memory and behaviour,
- Substantia nigra and subthalamic nucleus, despite being primarily in the midbrain, are sometimes included due to connections with lentiform nucleus.
- Corpus striatum is formed by the interconnecting fibers between the caudate nucleus and putamen.
- Globus pallidus is the main efferent pathway from the corpus striatum.
Caudate Nucleus
- Shaped like a curved comma (head, body, and tail).
- Head tapers into body, curving around thalamus into tail and connecting with amygdaloid body.
- Wraps around internal capsule, projecting into lateral ventricle's convexity.
Lentiform Nucleus
- Shaped like a biconvex lens, entirely within the hemisphere.
- Oval-shaped, composed of putamen (large, lateral, roughly quadrilateral) and globus pallidus (small, medial, bluntly conical).
- Connected to caudate nucleus head by myelinated and unmyelinated fibers, contributing to the striated appearance of the anterior part of the internal capsule.
Amygdaloid Body
- Consists of multiple nuclear masses.
- Connects to tail of caudate nucleus, located in inferior horn of lateral ventricle.
- Part of the limbic system.
Claustrum
- Thin, saucer-shaped lamina.
- Lateral to the putamen, identifiable in horizontal/coronal sections.
- Unknown significance.
Basal Nuclei Function
- Influence skeletal muscle movements (rate, range, coordination).
- Corpus striatum functions as input, receiving fibers from cerebral cortex, thalamus, and substantia nigra.
- Globus pallidus is the output side, sending fibres to thalamus, subthalamic nucleus, substantia nigra.
- Pathways use neurotransmitters like acetylcholine, dopamine, glutamate, serotonin, and GABA.
- Parkinsonism is a common disease affecting basal nuclei, featuring tremor, rigidity, and akinesia. Result of dopamine decrease in nigrostriatal pathway.
Cerebral Hemisphere White Matter
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Composed of fibres grouped in three main categories:
- Commissural fibres: Connect both hemispheres (mostly in corpus callosum, also anterior, posterior, and habenular commissures).
- Association fibres: Connect different parts of the same hemisphere's cortex.
- Projection fibres: Connect hemisphere's grey matter to subcortical nuclei, brainstem, and spinal cord.
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Internal capsule: Lies lateral to thalamus and caudate nucleus head, composed of afferent and efferent fibres; a major collection of projection fibers.
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Internal capsule parts (anterior limb, genu, posterior limb, sublentiform and retrolentiform parts) and their function.
- Anterior limb contains frontopontine fibres linking frontal cortex to cerebral peduncle (medial third); possible frontal eye field to oculomotor nucleus connections (reflexes).
- Genu is the bending area, contains corticonuclear fibres.
- Posterior limb includes corticospinal fibres controlling limbs (arm, hand, trunk, leg, perineum from anterior to posterior, cortex to lower medulla where they decussate and form lateral corticospinal tract). Injuries cause contralateral hemiplegia. Also includes speech/Broca's area fibres, where lesion will also cause right-sided hemiplegia and loss of speech
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Corona radiata: Fan-shaped radiation of fibres from and to the internal capsule, reaching cortex, intersected by corpus callosum fibers.
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Thalamocortical fibers and sensory impulses through the posterior limb.
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Corticopontine fibers from parietal, occipital, and temporal lobes to cerebral peduncle, connecting with visual/auditory radiation.
Corpus Callosum
- Composed of 100 million commissural fibers connecting symmetrical cortical areas.
- Four parts: rostrum, genu, body, and splenium.
- Fibers radiate to all cerebral cortex.
- Genu fibres form forceps minor, connecting frontal cortex.
- Splenium fibres form forceps major, connecting occipital cortex.
- Fibers form roof of lateral ventricle horns, forming tapetum as they descend.
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Description
Test your knowledge on the internal structures of the cerebrum, including the thalamus, basal nuclei, and cerebral cavities. This quiz covers the anatomy and functions of various components such as the caudate nucleus and corpus striatum. Challenge yourself and learn more about the complexities of brain structure!
