Thalamus
NervousOrgansHeadLeft and right
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- What it is
- An egg-shaped mass of grey matter on each side of the third ventricle, with a swollen back end (pulvinar) and the lateral and medial geniculate bodies beneath it.
- Function
- The relay and gatekeeper for almost all sensory information (except smell) and for motor loops on the way to the cortex; also important for arousal and attention.
- Size
- About 3 cm long, 1.5-2 cm wide and 2 cm high
- Clinical note
- A small thalamic stroke can cause loss of all sensation on the opposite side of the body, sometimes followed by severe burning pain (Dejerine-Roussy syndrome).