Vision: Vision is a physiological vocabulary. Light acts on the visual organs, which excites their sensory cells, and its information is processed by the visual nervous system to produce vision. People and animals perceive the size, brightness, color and movement of external objects through vision, and obtain all kinds of information that is of great significance to the survival of the body. Vision is the most important feeling for people and animals.
Hearing: Sound waves act on the auditory organs, which excites their sensory cells and makes the auditory nerves send out afferent information, which is caused by the analysis of auditory pathways at all levels.
Touch: Touch is the general term for mechanical stimuli such as contact, sliding and pressure.
Smell: Smell is a feeling. It involves two sensory systems, namely olfactory nervous system and nasal trigeminal nervous system.
Taste: Taste refers to a feeling that food stimulates the chemical sensory system of taste organs in human mouth.