Histology: Thalamus
THALAMUS and HYPOTHALAMUS
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February 14, 2011
DIENCEPHALON
Gross Features * No structure visible on the surface of the brain except the inferior surface. * Inferior surface is the only area exposed to the surface in the intact brain.
Extends from: * Anterior: Interventricular foramina * Posterior: Cerebral aqueduct
Boundaries: * Superior: * Lateral ventricle * Corpus callosum * Septum pellucidum * Fornix * Lateral: * Caudate nucleus * Internal capsule of white matter * Medial: * 3rd ventricle cavity of diencephalon bordered bilaterally of the thalamus and hypothalamus * Interthalamic adhesion * Connection between the two thalami
There are four major subdivisions of diencephalon, namely: 1. Thalamus (dorsal thalamus) 2. Hypothalamus 3. Subthalamus (ventral thalamus) – lies inferior to the thalamus 4. Epithalamus
THALAMUS * Large egg-shaped mass of gray matter that forms the major part of the diencephalon. * Situated on each side of the 3rd ventricle * Relay station for all sensory impulses except for OLFACTORY * Activities are closely related to that of the cerebral cortex * Any damage to thalamus causes great loss of cerebral function
Parts of the Thalamus: Divided into 3 parts
1. Internal Medullary Lamina * Y-shaped white matter that subdivides the thalamus into 3 main parts where different nucleus can be found: * Anterior: * Anterior thalamic nuclei * Medial: * Dorsomedial nucleus * Midline nucleus * Lateral: (several nuclei) – divided into tiers of layers * Dorsal tier of nuclei * Ventral tier of nuclei
Anterior Part Anterior thalamic nuclei * Receives mamillary input thru mamillothalamic tract from mamillary nuclei * Receives reciprocal connections (2-way connection –sends and receives impulses at the same time) from the cingulate gyrus and hypothalamus *
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February 14, 2011
DIENCEPHALON
Gross Features * No structure visible on the surface of the brain except the inferior surface. * Inferior surface is the only area exposed to the surface in the intact brain.
Extends from: * Anterior: Interventricular foramina * Posterior: Cerebral aqueduct
Boundaries: * Superior: * Lateral ventricle * Corpus callosum * Septum pellucidum * Fornix * Lateral: * Caudate nucleus * Internal capsule of white matter * Medial: * 3rd ventricle cavity of diencephalon bordered bilaterally of the thalamus and hypothalamus * Interthalamic adhesion * Connection between the two thalami
There are four major subdivisions of diencephalon, namely: 1. Thalamus (dorsal thalamus) 2. Hypothalamus 3. Subthalamus (ventral thalamus) – lies inferior to the thalamus 4. Epithalamus
THALAMUS * Large egg-shaped mass of gray matter that forms the major part of the diencephalon. * Situated on each side of the 3rd ventricle * Relay station for all sensory impulses except for OLFACTORY * Activities are closely related to that of the cerebral cortex * Any damage to thalamus causes great loss of cerebral function
Parts of the Thalamus: Divided into 3 parts
1. Internal Medullary Lamina * Y-shaped white matter that subdivides the thalamus into 3 main parts where different nucleus can be found: * Anterior: * Anterior thalamic nuclei * Medial: * Dorsomedial nucleus * Midline nucleus * Lateral: (several nuclei) – divided into tiers of layers * Dorsal tier of nuclei * Ventral tier of nuclei
Anterior Part Anterior thalamic nuclei * Receives mamillary input thru mamillothalamic tract from mamillary nuclei * Receives reciprocal connections (2-way connection –sends and receives impulses at the same time) from the cingulate gyrus and hypothalamus *