The human body has five senses: sight, taste, smell, hearing and touch. However, these are not the only senses that exist in the human body. There are other sensory or stimulus modalities including vibration, temperature, pain, balance and other stimuli for example various chemical receptors that detect carbon dioxide and salt concentrations in the body.
Sight is the ability of the eyes to interpret its environment by focusing and detecting images, and then relaying that information to the brain. This is possible, as the eyes contain photoreceptors that perceive brightness and color. This process allows human beings to see what is in their environment. The inability to see is known blindness.
The ears perceive the stimulus modality of sound or hearing. The act of hearing is associated with vibration. In the inner ear, there is an organ called the eardrum, which detects vibrations from the surrounding environment and relays the information to the brain. This process enables us to hear. However, people who are not able to hear suffer from deafness.
The tongue detects taste of things such as minerals and food. The tongue contains taste buds, which are sensory organs that detect five different tastes: sweet, salty, bitter, sour and umami. The condition of not being able to taste is known as ageusia.
The sense of smell is perceived by the nose. The nose contains receptor neurons called olfactory receptors that help detect the sense of smell from the surrounding environment. The condition of not being able to smell is called anosmia.