Sense Organs

Section: Understanding Sense Organs

  • Sense organs are specialised structures that help organisms respond to changes in their environment.
  • These organs contain receptors that are sensitive to specific types of stimulus.
  • The five main human sense organs are the eyes, ears, skin, nose, and tongue.

Section: The Eye

  • The eye is the organ of vision and contains receptors sensitive to light.
  • Light enters through the cornea and is focused onto the retina by the lens.
  • The retina contains two types of photoreceptors: rods for low light vision and cones for colour vision.
  • The optic nerve transmits visual information from the retina to the brain.

Section: The Ear

  • The ear is the organ of hearing and balance and contains receptors sensitive to sound waves and position.
  • Sound is collected by the outer ear and directed to the middle ear where it causes the eardrum to vibrate.
  • These vibrations are amplified by the ossicles and sent to the inner ear.
  • The cochlea in the inner ear translates these vibrations into electrical signals that are sent to the brain via the auditory nerve.

Section: The Nose and Tongue

  • The nose and tongue are the organs of smell and taste and contain chemoreceptors.
  • Olfactory receptors in the nose detect volatile substances we perceive as odours.
  • Taste buds in the tongue detect the taste of substances.
  • Taste is often enhanced by our sense of smell.

Section: The Skin

  • The skin is the largest sense organ and contains a range of different receptor types.
  • Receptors in the skin are sensitive to pressure, temperature, pain and touch.
  • Feedback from these receptors allows us to perceive our environment and respond appropriately.

Section: Sense Organs and the Central Nervous System

  • The central nervous system interprets signals from sense organs, forming our perception of the world.
  • Information from sense organs is relayed to the brain via nerves, where it is processed and interpreted.
  • This process allows us to make sense of our surroundings and react quickly to changes in the environment.

Section: Key Reminders about Sense Organs

  • Sense organs provide us with critical information about our environment.
  • They consist of specialised receptors that translate various stimuli into signals our brain can interpret.
  • The ability to sense our environment and respond to it is vital for survival.