The thalamus is located deep within the brain in the cerebral cortex, adjacent to the hypothalamus. It is a symmetrical structure, situated on top of the brain stem and on either side of the third cortex.
The two halves are bulb-shaped and are about 5.5 to 6.0 centimeters in length in the average adult.
Its chief function is processing information going to and from the spinal cord and cerebrum. It also regulates sleep cycles, consciousness, and alertness.
The thalamus receives information from nearly every sensory system, apart from the olfactory system, which it then sends to the relevant cortical area. Research has revealed that the thalamus doesn't simply relay the information, but also plays a part in processing it, ensuring that the information is correctly conducted to the primary cortex areas.
The thalamus also has strong connections with the cerebral cortex, and together they are involved with regulating consciousness; damage to the thalamus can lead to a permanent coma.
The thalamus also plays a major part in the control of the motor systems.