The Major Hormones of Endocrine System

The internal metabolism of our body is regulated and controlled by the various hormones produced by our Endocrine system. Various major phenomenon in body like growth, development, metabolism, reproduction, homeostasis and our body's response to stress, injury and external environment is coordinated and executed by the hormones. Here we will read about some of major hormones of our body and their function in our system.

INTRODUCTION

Hormones are the chemical substances produced in the body that acts as a messenger and transfer the important information from one group of cells to the other group. This helps in maintaining coordination between various essential functions of the body. Endocrine system consists of various glands that release hormones. Each hormone have its own specifies type and function. We can take it in this way that our endocrine system order any other part of body to do something and this command is take to the target organ by hormones. There are various glands in the body releasing different hormones and some of the major glands are pituitary, hypothalamus, pancreas, adrenals, parathyroid, thyroid, pineal body, ovaries and testes.

Let us learn about all these hormones and their influence on our body system.

1. Hypothalamus

This gland is located in the central lower part of the brain and controls metabolism, satiety and homeostasis. It releases major hormones like Growth hormone releasing hormone (GHRH), Thyrotropin releasing hormone (TRH), Gonadotropin releasing hormone (GnRH) and Corticotropin releasing hormone (CRH).

• Growth hormone releasing hormone (GHRH)- GHRH stimulates the anterior pituitary gland for the synthesis and release of growth hormone. Even many cells and organs functions are regulated by this hormone.
• Thyrotropin releasing hormone (TRH)- Its main function is to regulate and maintain secretion of thyroid stimulating hormone and eventually regulating thyroid hormone. TRH also control the release of growth hormone, prolactin, insulin and vasopressin.
• Gonadotropin releasing hormone (GnRH)- GnRH stimulates the pituitary gland which is situated in the brain to secrete the follicle-stimulating hormone and luteinizing hormone. These hormones in men regulate production of testosterone and in women progesterone and estrogen are released by it.
• Corticotropin releasing hormone (CRH)- CRH stimulates the pituitary gland to release adrenocorticotropic hormone. Corticotropin releasing hormone is known as the controller of stress hormone system (Hypothalamic-pituitary-adrenal axis).

2. Pituitary Gland

This small pea sized gland regulates the vital functions of the body and maintain the general wellbeing of a person. Pituitary gland is known as the master gland of the body as it plays the major role in regulation of important functions in the body. It releases several important hormones like Growth hormone, thyroid stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, prolactin, vasopressin and oxytocin.

• Growth hormone- As the name suggests this vital hormone regulates the growth of your body and helps children to grow tall, decreases fat of the body and increases muscle mass.
• Thyroid stimulating hormone- Pituitary gland produces this hormone and release it into the bloodstream. This hormone than travels to the thyroid gland, binds to the receptors on its cells and stimulates release of thyroxine and triiodothyronine hormones (thyroid hormones).
• Adrenocorticotropic hormone- This hormone is vital in order to maintain the proper stress reaction of your body. It regulates the function of adrenal glands and help body to react to stress. In adrenal gland, it also stimulates the gland to release cortisol hormone.
• Luteinizing hormone- LH in males stimulates the testes to release testosterone and in females stimulates ovaries to release steroid and progesterone.
• Prolactin- This amazing hormone is responsible for carrying out many functions in the body, mainly being the production of milk and mammary glands development.
• Vasopressin- Vasopressin is also known as anti-diuretic hormone which helps in retaining the body’s water. It is secreted by the posterior pituitary gland.
• Oxytocin- Oxytocin plays a major role in the female reproduction and it helps in breastfeeding by stimulation of nipples and during childbirth by inducing the labor.

3. Pancreas

Pancreas is an abdominal organ, elongated in shape and helps in digestion and release hormones. The exocrine part releases digestive enzymes and the endocrine part releases hormones, i.e. insulin and glucagon.

• Insulin- Insulin mediates the tyrosine kinase receptor pathway and promotes the glucose uptake by cells, glycogenesis, lipogenesis, synthesis of fats and protein of skeletal muscles. It helps in maintaining balance of blood sugar level.
• Glucagon- This hormone prevent from falling down the blood sugar level too low. Glucagon do this by stimulating the conversion of stored glycogen to glucose and then release it into the blood stream.

4. Adrenal Gland

There are two adrenal glands which are located on top of the kidneys. Adrenal gland is divided into two parts and the hormones are produced by outer part is called corticosteroids while the inner part produces catecholamines hormones.

• Corticosteroids- Its main function is to relieve the inflammation anywhere in the body. Corticosteroids provide relief from swelling, itching, redness and other allergic reactions.
• Catecholamines- The fight or flight reactions in the body is controlled by these hormones as they regulate the stress reaction and helps the body to fight against and fright or terror to oneself.

5. Parathyroid Gland

Parathormone hormone is produced by the Parathyroid gland and is also known as Parathyrin hormone. It regulates the serum calcium concentration.

6. Thyroid Gland

Lower front part of the neck holds the thyroid gland that produces hormones to regulate the metabolism of the body. Thyroid hormone helps in development of nervous system, brain and bones in the children. Blood pressure, muscle tone, digestion, heart rate and reproductive functions are also regulated by thyroid hormone to certain extent.

7. Pineal Body

Pineal gland or pineal body is found in the middle area of the brain. A hormone which regulates the wake-sleep cycle of the human body called as Melatonin is produced by the Pineal gland. Other than this Melatonin also plays a role in regulation of blood pressure, immune system, and autonomic cardiovascular regulation.

8. Ovaries

Two major sex hormones are produced by this gland called estrogen and progesterone. Both the hormones help in regulation of the menstrual cycle and play a vital role in pregnancy. These hormones are necessary for the reproductive and sexual development of the women.

9. Testes

Testosterone is the major hormone produced by testes which plays the major role in sexual development and reproductive health of the men. It helps in regulating libido, distribution of fat and muscles, strength, and production of sperms and RBCs.

CONCLUSION

Endocrine system of the body is vital part of human system that plays the essential role in unhindered functioning of the human body. Coordinated and controlled functioning is carried with various hormones regulation. Other than the above mentioned ones, there are many other hormones as well which play their roles in different aspects of the body system.