Final answer:
The thalamus is responsible for receiving sensory input from various stimuli and plays a crucial role in regulating the level of arousal and consciousness in the brain.
Step-by-step explanation:
The part of the brain that receives sensory input from a variety of stimuli and assists with the level of arousal and consciousness is the thalamus. Functioning as a sensory relay station, the thalamus acts as a gateway for information to and from the cortex, playing a vital role in modulating conscious awareness of sensory and motor inputs based on the attention and arousal state.
It facilitates the processing of sensory signals to the cerebral cortex and motor signals to the spinal cord, regulating consciousness, arousal, and sleep states. All sensory information, except for the sense of smell, passes through the thalamus before being sent to other areas of the brain for further processing.