Final answer:
The fan-shaped sheet of axons that connects the cortical surface to the thalamus is known as the corona radiata. The thalamus is essential for processing sensory and motor signals and plays a role in consciousness, arousal, and sleep states. It relays and processes information from all sensory pathways, except for the sense of smell.
Step-by-step explanation:
The fan-shaped sheet of axons that runs between the cortical surface and the thalamus is known as the corona radiata. The thalamus is pivotal in processing sensory and motor signals, and it also has crucial functions in maintaining consciousness, arousal, and sleep states. Information from sensory pathways, except for olfaction, passes through the thalamus before reaching the cortex. Moreover, the thalamus processes this information by emphasizing certain stimuli over others, based on attention and significance. The spinothalamic tract, for instance, is involved in carrying pain and temperature sensory information to the thalamus, then projecting to the cerebral cortex. The thalamus consists of several nuclei grouped anatomically into anterior, medial, and lateral regions, with each group having specific functional connections to various parts of the brain and body.