A key set of structures in the limbic system handles emotion, memory, and related drives. The hippocampal formation is central to forming and retrieving memories and spatial context. The parahippocampal gyrus supports memory encoding and contextual associations around the hippocampus. The amygdala assigns emotional significance to stimuli, influences emotional responses, and modulates memory consolidation—especially for emotionally charged events. Together, these regions link memory with affect and drives, helping regulate behaviors like feeding and reproduction by integrating past experiences and current emotional states with motivational needs, via connections to other limbic and hypothalamic circuits. The other options don’t fit as well because they involve regions not primarily part of the limbic system or not the main players in memory and emotion: the basal ganglia (caudate, putamen, globus pallidus) are mainly motor control circuits; the cerebellum, brainstem, and thalamus have broader roles in movement coordination and relay functions; the frontal, parietal, and temporal lobes are large cortical areas, not the specific limbic structures responsible for memory and emotion.

Thermoregulation is controlled by hypothalamic zones, with the anterior area acting as the heat-dissipation center. When core temperature rises, this region triggers cooling mechanisms like sweating and vasodilation to shed heat. The posterior region serves as the heat-conservation and heat-production center, activating shivering and vasoconstriction to preserve or generate warmth. So pairing the anterior zone with heat dissipation via sweating and the posterior zone with heat conservation via shivering matches the physiological roles of these areas. The other options mix in functions like appetite, thirst, or circadian control, which aren’t the primary temperature-regulating roles of these zones.

The key idea is how the brain wires the two halves together. The corpus callosum is the major white matter tract that spans the midline, linking the left and right cerebral hemispheres so they can share information. It’s the largest bundle of commissural fibers in the brain, enabling rapid transfer of sensory, motor, and cognitive signals between hemispheres. The other structures have different roles: the thalamus acts as a relay within a hemisphere, the cerebellum coordinates movement and sits with connections to the brainstem and cortex, and the amygdala handles emotion processing within a hemisphere. So the corpus callosum best fits the description of connecting the two hemispheres.

Kinesthesia is the sense of limb movement and position. Proprioceptors in muscles, tendons, and joints detect stretch and movement and send signals to the brain, letting you know where your limbs are and how they’re moving, even without looking. This distinguishes it from tastes, colors, and sounds, which are gustatory, visual, and auditory modalities.