ABSTRACT
Charles Scott Sherrington (1857-1952) was an English neurophysiologist, histologist, bacteriologist, and pathologist. He received the Nobel Prize in Physiology or Medicine in 1932. In 1906, Sir Sherrington introduced the terms “exteroception”, “interoception”, and “proprioception”. Exteroception
Exteroception is the sense by which one perceives the outside world. The “exteroceptors” are the sensors for gathering information from outside the body and are embedded within organs such as the eyes, ears, mouth, nose and skin. These include: • Sight or vision photoreceptors: Two different types of receptors in the retina of each eye are responsible for the perception of color (cones) and brightness (rods). The retina,
which is the size of thumbnail, is filled with approximately 150
million light-sensitive cells. The retina is a light-sensitive layer of tissue that lines the back of the eyeball and sends visual messages through the optic nerve to the brain.
