Touch Response to a mechanical stimulus. The skin is the largest sensory organ. Sensory receptors detect pressure, pain, heat, cold.

Smell Response to a _chemical_____ stimulus. Sensory receptor cells are bathed in mucus and respond to different chemicals

Taste Response to a _chemical_stimulus. Sensory receptors called _taste buds_ are located on the _tongue. Detect sweet, sour, salty, bitter

Vision Response to a _light___ stimulus. Cornea – Light first passes through the _cornea_____, a transparent, protective covering which begins _focusing___ the light. The light then enters a chamber filled then enters a chamber filled with watery fluid called the _aqueous humor. _Pupil____ - Hole that light passes through. The size of the pupil is controlled by a ring of muscles known as the _iris___. _Lens____ - Completes focusing of the light ray. There is also a thick jelly-like substance to help maintain the shape of the chamber known as the _vitreous humor_. Retina – Nerve tissue at the back of the eyeball that converts light energy to an _electrical impulse_. Made up of two types of cells: Rods - Cells that detect _shape & movement; are stimulated even in _dim___ light. Cones - Cells that detect _color; provide a _sharp image; require _bright light for stimulation. Optic Nerve - Transmits the impulse to the _brain___. Additional Structures Sclera - _”White of the eye”; continuation of the _cornea Choroid - Layer of blood vessels that _nourish the eye.