The glands that make up the endocrine system produce chemical messengers called hormones that travel through the blood to other parts of the body. Important endocrine glands include the pituitary, thyroid, parathyroid, thymus, and adrenal glands.
The endocrine system is made up of the endocrine glands that secrete hormones. Although there are eight major endocrine glands scattered throughout the body, they are still considered to be one system because they have similar functions, similar mechanisms of influence, and many important interrelationships.
DDT is biologically magnified and concentrated as it moves through the food web. This increase in concentration is due to Metabolism of DDT which excretes more slowly than the nutrients which moves from one trophic level to next. so DDT accumulates in the body especially in the Fats.