Interoception:
The sensation of internal bodily signals such as heartbeat, hunger, thirst, or breathing. Helps maintain homeostasis by allowing the brain to monitor and regulate internal states. For example, feeling thirsty signals the need for hydration. Exteroception
The sensation of external stimuli from the environment, such as light, sound, temperature, or touch. These two sensory systems work together to provide a picture of both internal and external worlds, enabling adaptive responses to physical and environmental changes.