THE ENDOCRINE SYSTEMA second control system

It is a series of organs called GLANDS.

These glands secrete chemicals called HORMONES (which are proteins).

The hormones once released travel in the blood to any part of the body.

The hormones affect only their TARGET ORGANS.

The target organs are the ones that have RECEPTORS for the hormone, so they can recognise them.

Hormone responses last a long time. Ex: growth hormone sex hormones

The target organs carry out responses.Ex: growth of the hair. sexual maturity.