SYSTEMS OF COORDINATION

Animals have two systems for coordinanting and regulating their life functions:the two work closely together.

Nervous system.Consists of specialized cells called neurons.Neurons transmit information as nerve impulses.The impulses travel along the branches of the neuron which form cords called nerves.

Endocrine system.This system consists of endocrine glands distributed throughout the body.Endocrine glands produce chemical substances called hormones into the blood.Act on cells and organs.Hormones generally produce longer-lasting.

The organization of the endocrine system in animals

Animal groups:

 Invertebrates.The endocrine system consists of specialized nerve cells.Some groups,have hormone glands.The endocrine system is involved in processes like reproduction or metamorphosis.

Vertebrates.The endocrine system consist of endocrine glands.These glands produce hormones,the development of sex characteristics and other functions.