Human growth hormone
Introduction The physiological and biological nature of the human anatomy is indeed complex involving different aspects of changes and processes in the course of its development. As an individual grows towards maturity, he meets with the different issues that are related with the changes that he is supposed to undergo for the sake of better growth development. From a child’s birth towards the growth of a man, the growth hormones of an individual plays a great role in identifying how a person looks, how his physical systems work and how he naturally becomes as an individual. Everything naturally begins with the pituitary glands.
The overseer of the endocrine system is the pituitary, a small, reddish-gray organ that is attached to the brain by a slender stalk and that lies in a bony pocket just behind and above the nose. The pituitary is not impressive to look at. It is only the size of a pea, and it weighs a mere 0. 02 ounce [0. 6 gm]. But even though the pituitary is small, its responsibility is immense. It has been called the master gland, the conductor of the endocrine orchestra. It is like a business executive whose office is a flurry of activity, with messages coming from and going to many departments.
Some jobs the pituitary delegates to other endocrine glands. For example, the pituitary launches a hormonal message into the bloodstream ordering the thyroid gland to produce and release three other hormones. These control metabolism, body heat, and bone maintenance. The pituitary likewise commands the sex glands to produce the hormones that will bring about the physical changes of puberty. The master gland can also instruct the adrenals to manufacture hormones that maintain blood pressure and salt balance in the body.
At times, though, the pituitary cares for matters directly, sending out hormonal messages that influence the growth of our bones and muscles. Its hormones even control how tall we will be. The pituitary further plays a big role in delivering babies. To assist a woman in labor, the pituitary sends out oxytocin, a hormone that stimulates contractions of the womb. When the baby’s head reaches the birth canal, the brain sends a message to the pituitary requesting an extra supply of oxytocin to help with the final phase of delivery.
All along, hormones from the pituitary have been stimulating the production of milk in the mother’s breasts. When baby is born, mother is equipped to feed it. With the pituitary gland beginning the cycle of the functional role of the growth hormones in the growth of a person, the identification of the importance of growth hormones to one person is defined in clarity. The Human Growth Hormone (HGH) While the pituitary is the overseer of other glands, it has its own overseer—the hypothalamus. This is a cluster of nerve cells no larger than the tip of your thumb.
It is located at the base of the brain and is connected to the pituitary. Its job is not only to supervise the work of the endocrine system but also to coordinate the work of the autonomic nervous system. Part of its work is to test the makeup and temperature of the blood. More blood gushes through the hypothalamus than any other part of the brain. Into this blood flow, the hypothalamus pokes wrinkled fingerlike sensors, much as a bather uses his finger to test the temperature of the water in his tub.
If the blood is too cool, the hypothalamus sends instructions (via the pituitary and the thyroid) for more thyroxine, a hormone that boosts metabolism to produce heat to warm the blood. Since the hypothalamus does its work automatically, we are usually unaware of its labors. Yet, it has a day-to-day effect on our lives. Are you hungry? Your hypothalamus has detected too little glucose in your blood, so it is telling you to eat. Are you thirsty? Your hypothalamus has decided that the salt level in your blood is a little too high. “Drink some water,” it tells you.
The hypothalamus also monitors levels of calcium in the blood. Without calcium our brain, muscles, and nerves would not work properly. When the level of blood calcium is too low, the hypothalamus withdraws calcium from the bones, much as a person withdraws money from a bank. How is the calcium withdrawal made? The hypothalamus sends a hormonal message to the pituitary. The pituitary launches its own command to the parathyroids, located in the neck. The parathyroids, in turn, secrete parathormone, which goes to the bones to request calcium for the bloodstream.
Once the hypothalamus sees that the calcium level is correct, it cancels orders for further withdrawals. But what if the hypothalamus learns that there is too much calcium in the blood? Once again messengers are sent to the ‘bone bank,’ but instead of making a withdrawal, they make a deposit. This is the procedure: The hypothalamus sends a message to its chief executive, the pituitary. The pituitary now issues a command to the thyroid. The thyroid, in turn, sends out the hormone calcitonin, which acts to transfer excess calcium from the blood to the bones.