|Class 10 Biology Control and Coordination||Hormonal system in animals|
Electrical impulses are excellent means for transmission of information but there are few limitations of using electrical impulses-
Impulses reach only those cells that are connected with nervous tissue.
Cells cannot continuously create and transmit impulse, the cells need some time to reset the mechanism before these can create and generate a new impulse.
Due the limitations, instead of generating electrical impulse, the stimulated cells release a chemical compound called hormones.
Hormones will diffuse to all the cells of the body and the cells have receptors to detect the hormones and to receive the information and transmit it.
Hormones are the chemical messengers which are secreted by the endocrine gland into the blood.
Different animal hormones are-
Fig. endocrine system
For eg. If sugar level increases in blood, cells of the pancreas can detect this and produce more amount of insulin to control blood sugar and as the blood sugar level falls, secretion of insulin reduces.