Functions of Endocrine System

Blood Circulation

Hormones are chemical substances, produced in the body, that carry out or trigger a large number of processes of vital biological importance, including behavioral changes, reproduction, growth, psychological wellbeing, and so on. In short, all the essential mechanisms in the body are owed to the potential effects and functionality of the hormones. To have an idea about the real worth of the human endocrine system, one can rightly say that without the presence of this mechanism life would have been crippled or almost impossible on the planet earth.

For example, in the absence of epinephrine and norepinephrine, the regulation of the heartbeat rate, blood pressure and blood glucose level would have been extremely difficult. Anyhow, if you want to keep the hormone-secreting organs hale and hearty and enjoy the life at its fullest, you are advised to have basic information about the functioning of this system, as given below:


Homeostasis refers to the stability of the internal body environment, as opposed to the fluctuations in the external environment, and the same is very necessary for the survival of a living being. You can better understand the importance of homeostasis in the light of life system parameters. Being endothermic, human beings can easily maintain constant body temperature, while ectothermic organisms, on the other hand are unable to do so.

So the latter have a wide range of temperature variations depending on the corresponding environmental conditions. That is why, in low temperatures, the ectothermic animals may become lethargic, while the warm-blooded animals tend to be normal in their functioning. All this is primarily owed to the action of hormones that are produced and controlled by the endocrine system.


There is no denying the fact that the hormones, present in the digestive tract, play a key role in controlling the intake of food and the expenditure of energy. Do you know that gut is the largest hormone producing organ in the body as it releases as many as 20 different types of peptide hormones? Some of these hormonal secretions target the brain, thus regulating appetite and influencing the pleasure of eating. For the extraction and utilization of available energy, the dietary items are broken down with the help of chemicals. The energy thus produced is captured in the form of ATP (Adenosine Tri-Phosphate) which is then transported to the area in the body where it is needed.


The growth of the skeleton as well as muscles is controlled by the growth hormone. Synthesized and secreted by the endocrine cells, called somatotrophs, in the anterior lobe of the pituitary gland, growth hormone is a protein hormone that is composed of 190 amino acids. It plays a very significant role in a number of physiological processes, taking place in your body, including metabolism and growth. Interestingly, the growth hormone is also used as a drug both in humans and animals for the treatment of retarded growth.

Sexual Maturity and Reproduction

It is because of the action of particular hormones that you gradually move from sexual immaturity towards maturity. Along with the development of primary sex organs, the male & female secondary sexual features develop with the assistance of reproductive hormones. Operating via negative feedback system, the hormones of the reproductive system often have multiple roles. Estrogen is a steroid hormone which is responsible for the conversion of a girl into a sexually mature woman. Moreover, the development of breasts, uterus, vagina, broadening of pelvis, growth of pubic & axillary hair, monthly preparation for pregnancy and participation in pregnancy are also owed to the potentially important role of estrogen in the body of a female.

The non-productive role of estrogen includes the promotion of blood clotting, and antagonizing the effects of parathyroid gland. Likewise, progesterone is also a steroid hormone which performs both the productive as well as nonproductive functions in the body.

Blood Pressure Control

The hormones, like rennin anThe hormones, like rennin and angiotensin are produced by the healthy kidneys and help control blood pressure by means of regulating the amount of water in the body, and maintaining proper width of arteries. These chemical substances regulate the amount of sodium salt and fluid that the body keeps as well as how well the blood vessels expand and contract.

Blood Sugar Control

Insulin and glucagon are the two hormones that collectively play the largest role in the maintenance of the blood sugar level in the body. As both insulin and glucagon are produced by the pancreas, so they are termed as the pancreatic endocrine hormones. From the production of these two regulatory substances, one can ultimately determine whether a patient is suffering from diabetes, hypoglycemia or some other sugar problem.

Both of these substances are produced in response to blood sugar levels but in and opposite fashion! A high blood glucose level serves as a stimulus for the secretion and release of insulin from the beta islet cells of pancreas, thus bringing a decrease in the glucose content of the blood. In quite the same way, a low blood glucose level triggers the secretion of glucagon which converts glycogen into glucose, thus bringing the glucose content of the blood back to normal limits.

About the Author

Posted by: M. Isaac / Senior writer

A graduate in biological sciences and a PhD scholar (NCBA&E University, Lahore), M. Isaac combines his vast experience with a keen and critical eye to create practical and inherently engaging content on the human body. His background as a researcher and instructor at a secondary school enables him to best understand the needs of the beginner level learners and the amateur readers and educate them about how their body works, and how they can adopt a healthier lifestyle.

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