The use of punctuation in English can change from place to place and from time to time. Modern typography suggests that punctuation should only be used when there is a need. That results in less punctuation than was the case the early 20th century.
Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland. Hormones are essential for every activity of life, including the processes of digestion, metabolism, growth, reproduction, and mood control. Many hormones, such as neurotransmitters, are active in more than one physical process.
A hormone (from Greek á½ÏÎ¼Î®, impetus) is any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour. Transport of the hormone to the target cell(s). 2  Recognition of the hormone by an associated cell membrane or intracellular receptor protein. 3  Relay and amplification of the received hormonal signal via a signal transduction process: This then leads to a cellular response.