A list of often difficult or specialised words with their definitions.
The time of gradual development of the secondary sexual characteristics and sexual maturity.
A chemical messenger produced by a particular gland or cells of the endocrine system. Hormones are transported throughout the body in the blood stream but they produce a response only in specific target cells
The basic unit from which all living organisms are built up, consisting of a cell membrane surrounding cytoplasm and a nucleus.
A group of cells which produce and secrete a particular substance. Many glands pass their secretions into a tube or duct, whereas endocrine glands secrete hormones directly into the blood.
Hormones are chemical substances in the body. They are made by endocrine glands which pass the hormones directly into the bloodstream. They are carried around the body in the blood and, in this way, hormones can cause changes at some distance from the gland where they were made.
Many processes in the body are coordinated by hormones which regulate and balance the working of organs and cells.
Some hormones have long term effects, for example, the hormones that control how we grow and the changes that happen at puberty. Other hormones have shorter term effects.
Too much, or too little, of a hormone can cause illness. Synthetic hormones, developed by pharmaceutical companies, have resulted in a great improvement in the quality of life of patients suffering from many of these illnesses.
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