Sense Organs

OB28 recall five sense organs in the human and understand how these enable humans to gather information from their surroundings

What parts of your body sense or detect changes in the environment?

What do each of these Sense Organ do

and understand how these enable humans to gather information from their surroundings


  1. Eye position
  2. Human Nose Vs other creatures noses
  3. The Importance of Hearing
  4. The effect of smell on taste
  5. The range of information that skin can transmit

How important Dogs Noses are to their environment

OB30 locate the main parts of the eye on a model or diagram and describe the function of the cornea, iris, lens, pupil, retina, optic nerve and ciliary muscle

Here is an image of the eye, you are expected to be able to label and explain the functions of the parts in the table below

Write out the following table

You must be able to locate the parts on a drawing of the eye,

you also need to know the functions of these parts

To witness the iris (pupil) at work, Dim the lights in a room. After a few minutes, look at the eyes of another person and note the size of the pupil (the black center spot in the middle of the eye). Turn the room lights back on. Check the size of the pupils again. The pupils should now be smaller. This is the pupillary response: it "automatically" keeps out excessive light that may damage the eye.

Where the optic nerve leaves the eye to transmit signals to the brain, leads to a blind spot in our vision

Find your blind spot

Look at the diagram below, at eye level

Close your right eye

approach the screen while always watching the cross on the right.

you can still see the ball on the left, until .... this is your blind spot where the the optic nerve leaves the eyeball

If you look at the left object close your left eye

John Dalton, man who discovered there were inner workings of the atom, had colourblindness.

A small test of colourblindness is on his wiki page.

Illusions are based on the difference between what we see and what we think we see

How many people can you see in this picture.

The best illusions are here at

The best course and description of ILLUSIONS is here at

Here is an image of the Ear (it is not on the course)

An interactive test!

Here is an image of a Flavour Map for the Tongue

Here is an image of Skin