The only exception lies for the pituitary gland, where the signals are sent by the hypothalamus to the pituitary gland in the form of a releasing hormone. As a result, a stimulating hormone is released into the circulation. This then stimulates the target gland to release the required amount of the hormone. When the required amount is reached in the bloodstream, the hypothalamus and the pituitary stop the production of the releasing and the stimulating hormone.Any malfunctioning in this whole system results either in an increased or a decreased release of the hormones in the body, thereby producing a different kind of diseases accordingly. As an example, an increase in the production of the growth hormone results in an abnormally tall height, while a decrease results in a condition called as dwarfism, characterized by a very short height.The hormones are the chemical messengers released by the endocrine glands. They are the main regulators of metabolism, growth, development, and reproduction. they play an important role in homeostasis and the fluid and electrolyte balance. They are released either by the specialized endocrine cells, or the specialized nerve cells called the ‘neurosecretory cells’ (2). Based on their chemical structures, the hormones can be classified into the following four categories:The prostaglandins or the tissue hormones are found in a variety of tissues and they influence different body functions like respiration, blood pressure, gastrointestinal secretions, and reproduction. (3)The hypothalamus lies in the lower central part of the brain. The main functions performed by the hypothalamus include the regulation of satiety, metabolism and body temperature.