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.