Endocrine glands and Endocrine system

Endocrine glands (Gr., endo = within + krinein = to secrete):

These glands lack ducts and pass secretions into the surrounding blood directly. Therefore they called ductless glands. e.g. – Thyroid, parathyroid, adrenal, pituitary, pineal body and thymus.

Endocrine system:

the work of co-ordination by endocrine system is slowly by secretion of some chemical substances.

Hormones are secreted in blood

Virtually all body cells

Change in metabolic rate

Seconds to hours or days generally long.