About Five Senses
The traditional five senses are sight, hearing, smell, taste, and touch, but the nervous system also senses balance, body position, temperature, pain, and internal conditions. Sensation begins when specialized receptor cells detect a form of energy or chemical signal.
Sight
Vision begins when retinal cells detect light.
Learn MoreHearing
Sound waves are converted into nerve signals inside the inner ear.
Learn MoreSmell
Olfactory receptors detect airborne molecules that dissolve in mucus high inside the nose.
Learn MoreTaste
Taste buds detect several basic taste qualities.
Learn MoreTouch
Skin contains several kinds of sensory endings.
Learn MoreBalance
The inner ear helps detect head rotation and linear movement.
Learn MoreBody Position
Proprioception is the sense of where body parts are without looking.
Learn MoreSenses Work Together
The brain combines sensory streams into one useful picture of the world.
Learn MoreSight
The cornea and lens focus an image on the retina. Rods work well in dim light, while cones support color vision and sharp detail. Signals travel through the optic nerve to several brain regions.
Hearing
The eardrum and tiny middle-ear bones transmit vibrations to the fluid-filled cochlea. Hair cells inside the cochlea bend in response to motion and activate auditory nerve fibers.
Smell
Humans have hundreds of receptor types. The pattern of receptors activated by an odor is processed by brain networks closely connected with memory and emotion.
Taste
Commonly recognized tastes include sweet, sour, salty, bitter, and umami. Flavor also depends heavily on smell, temperature, texture, and signals from irritation-sensitive nerve endings.
Touch
Receptors respond to light touch, pressure, vibration, stretching, temperature, and tissue damage. Different body regions have different receptor densities, which is why fingertips can distinguish fine details better than many other areas.
Balance
Semicircular canals contain fluid that shifts when the head turns. Other structures sense gravity and straight-line acceleration. The brain combines this information with vision and signals from muscles and joints.
Body Position
Receptors in muscles, tendons, and joints continuously report length, tension, and position. This information is essential for coordinated movement.
Senses Work Together
Vision can influence balance, smell affects flavor, and touch can help identify objects that are difficult to see. Perception is an active process built from many signals at once.