Thalamus and hypothalamus Flashcards
Describe the anatomy of the thalamus
It is part of the diencephalon (thalamus, hypothalamus, sub thalamic nucleus). It is divided into left and right by the third ventricle each being a collection of individual nuclei. They have separate functions and connections with ipsilateral forebrain structures.
How is the thalamus separated from the caudate nucleus?
by the internal capsule
What are the functions of the thalamus?
- Relay centre between the cerebral cortex and other parts of the CNS
- Integrates/modulates information en route
- Involved in all functions except olfaction
- Some nuclei form part of the Reticular Activating System.
How are the nuclei in the thalamus classed? (according to the connection of the nuclei to the cortex)
Specific β connected to primary cortical areas.
Association β connected to association cortex.
Intralaminar β connected to all cortical areas.
Reticular β not connected to the cortex.
Where is the thalamus located?
In the middle of the brain under the posterior half of the corpus callosum
What divides the thalamus?
the 3rd ventricle
What sense isnβt the thalamus involved in?
olfaction
How are nuclei named?
According to the position e.g. ventral lateral
Which nuclei link to the motor cortices (primary, premotor and supplementary)?
ALL ALONGSIDE EACHOTHER
Ventral lateral and ventral anterior
Which nuclei link to the somatosensory head cortex?
ventral posteromedial
Which nuclei link to the somatosensory body cortex?
ventral posterolateral
Which nuclei link to the visual cortex?
lateral geniculate
Which nuclei link to the auditory cortex?
medial geniculate
How can the association cortices be divided into 3 areas?
According to thalamic function:
Prefrontal Cortex - most of the frontal lobe except for the primary motor cortex and some other motor cortical areas
Parieto-tempero-occipital Cortex - consists of all of the cortex in the parietal, temporal and occipital lobes except for the primary cortical areas
Cingulate Cortex - it follows the line of the corpus callosum
Where do the association nuclei project?
The mammillary bodies, the hypothalamus, the cingulate and prefrontal cortices.
Where do the anterior, lateral dorsal and dorsomedial association nuclei project?
mamillary body, hypothalamus, cingulate and prefrontal crotex
Where does the lateral posterior association nuclei project?
parieto temporo occipital