Sensory system

A sense organ is an organ that converts specific information in the form of stimuli from the environment into electrical impulses. These are available through nerve fibers, filtered, matched with information from other sense organs and stored information and combined and contribute to the generation of perception through in the brain. The conversion of specific stimuli for the sense organ is made by its receptors.

Stimuli of the environment and the significance for their conversion sense organs

Light

The convertible to the human eye is known as the electromagnetic radiation to visible light. The eyes of some animals are also sensitive to the short-wave ultraviolet and / or the longer-wavelength infrared light.

  • Visible light: wavelength 380 nm ( violet) to 760 nm ( red) → eyes ( sight )
  • Ultraviolet light eye → Many insects, some reptiles, some birds, deep-sea fish
  • Infrared radiation can perceive some of freshwater fish on the eyes.

Specific stimulus: light waves Receptor structure: retina with rods and cones (rods for the light-dark vision and cones for color vision )

Sound

  • Audible sound: 16-20000 Hz → ear ( hearing ) of man. Deaf people can sound via the skull bone, the skin, the lips, the hands, the inside of the arms and other body parts feel.
  • Ultrasound: wavelength ~ 20 kHz ( 17.5 mm) - 200 kHz ( 1.7 mm) → ear of certain animals such as bats and dolphins
  • Infrasound: 16-0 Hz → ear of certain animals such as elephants and owls and smooth transition to the sense of touch
  • Vibrations → touch receptors (vibration) in the skin ( touch) and vibrissae and vibration receptors in insects and spiders

Temperature

  • Infrared radiation / heat: wavelength 750 nm -0, 01 mm → heat and cold receptors in the skin ( temperature perception), pit organs in snakes

Pressure and movement

  • Pressure → touch receptors in the skin ( touch)
  • Water pressure and movement → lateral line organ in fish
  • Foreign movements → peripheral vision of the eye in primates, altering the properties of the sound ( relative loudness, timbre )
  • Proper motion and position of the body relative to the environment → balance organ in the inner ear ( sense of balance )
  • Position of the body parts → receptors in the muscles and joints ( Golgi tendon organ, muscle spindle, See also proprioception ), Chordotonalorgan in insects

Chemical stimuli

  • Olfactory mucosa ( sense of smell )
  • Taste buds on the tongue ( taste), for example, in the arachnids

Electric fields

  • Ampullae of Lorenzini in sharks and rays
  • Perception electric fields in some predatory fish (electric fish) such as eel and electric ray. Also for the Guyana dolphin 's ability to electroreception is occupied.

Magnetic fields

  • Perception of the geomagnetic field (not only) in migratory birds due to a magnetic sense ( at robins in mind, in pigeons in the beak skin). Strong magnetic fields can also be detected by man by vibration of the eyes.
Organ (anatomy) Oceanic dolphin Somatosensory system Infrared sensing in snakes Vestibular system Odor Tucuxi Sensory substitution
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