The eye sense organs detect visible light

The human eye detects visible light frequencies/wavelengths - that's why these are referred to a s 'visible' light or the 'visible spectrum'. The eye and associated optics are described in detail on the following two pages.

The eye - structure and function - correction of vision defects (GCSE biology notes)

Optics - types of lens and uses, experiments, ray diagrams, correction of eye defects (GCSE physics notes)

The nose sense organ detects chemical odours ('smells')

The inner roof of nose houses the olfactory system whose receptor cells detect chemicals in the air - 'your sense of smell'.

These olfactory cells respond to different chemicals and you perceive the different generated nerve signals as a different smells.

The odours may be aesthetically pleasing or unpleasant to your sense of smell.

Animals can emit and detect very small quantities of molecules called pheromones - often for sexual attraction strategies.

The jury is out on whether this applies to human beings other than specially designed perfumes, which perform the same role sometimes!

A pheromone is defined as a secreted or excreted chemical substance that triggers a social response in members of the same species.

Pheromone molecules are capable of acting like hormones outside the body of the secreting individual, to affect the behaviour of the receiving individuals of the same species.

You skin senses can detect physical contact (touch), temperature ('hot and cold' surfaces) and chemicals

Your skin has a variety of receptor cells that respond to:

(i) A physical contact with the skin, from light touching to detecting pressure.

(ii) A change in temperature on the skin surface e.g. cold air or a hot surface.

(iii) The skin responds to irritating chemicals that cause inflammation e.g. acids or alkalis.

The tongue - detects the taste of different substances (different chemical)

Receptor cells on your tongue surface respond to different chemical substances and the nerve signals generated are perceived as 'taste', which may be pleasant or unpleasant.