Select Board & Class


Beyond the Senses

Sense Organs: Organs that helps us to be aware of our surroundings are known as sense organs.

Receptors: Any cell or tissue sensitive to a selective stimuli are called receptors.


Composed of three layers:

  • Outermost layer- sclera and cornea
  • Middle layer- choroid, ciliary body, iris
  • Innermost layer- retina, with rod cells and cone cells.
  • Just behind the iris, a transparent, biconvex, and elastic structure called lens is present.
  • Rods – Contain rhodopsin pigment that is highly sensitive to dim light

  • Cones – Contain iodopsin pigment that is sensitive to high intensity light. Cones are also responsible for colour vision.

  • Blind spot – Area where photoreceptors such as rods and cones are absent

  • Fovea – Area that contains only cones. Vision is finest and sharpest in this zone.

  • Aqueous chamber – Space between cornea and lens; contains aqueous humour.

  • Vit…

To view the complete topic, please

What are you looking for?