Source: Video and Images Created by Amanda Soderlind
Welcome to this lesson on growth hormone.
Today we will be discussing the role of the growth hormone in the body, and also the role that it plays in the endocrine system.
The growth hormone is a hormone that's secreted by the anterior lobe of the pituitary gland.
The pituitary gland is located in the brain.
Sometimes the regulation of this hormone can get a little off whack. Sometimes too much of this hormone can be secreted, and sometimes too little of this hormone can be secreted.
If too much or too little is secreted, it can lead to some sort of abnormal growth.
So right here, where I have GH, this stands for growth hormone. It's an abbreviation for growth hormone.
If too much growth hormone is secreted by the anterior lobe of the pituitary gland, it can lead to a disorder called gigantism.
Gigantism is a condition in which too much hormone is released during childhood. And basically, the outcome is a person that is much larger than average.
The person will have normal body proportions. However, they will be much taller and much larger than the average person, because this anterior lobe of the pituitary gland is secreting too much growth hormone.
Normally growth hormone regulates how tall we get, and the epithesial plates of our bones, in conjunction with growth hormone, help a person reach a normal height. But if too much growth hormone is being secreted, then the person is going to be much taller than they normally would. The bones are allowed to continue to grow abnormally.
Growth hormone overproduction can also affect adults. In this disorder, it's affecting children. So children are growing too tall. But if something happens where once a person reaches adulthood, and growth hormone starts being overproduced, the person is not going to be able to grow any taller, because epithesial plates have calcified over. So instead what happens is that tissues become thicker.
So basically, tissues like the bone, skin, cartilage, the tissues of the face, the hands, the feet, are all going to become abnormally thick. So the person is not going to grow any taller, but their tissues will become thicker.
This is another way that growth hormone overproduction can affect a person.
On the other hand, sometimes too little growth hormone can be secreted.
If not enough, or too little, growth hormone is secreted, it can lead to pituitary dwarfism.
In pituitary dwarfism, basically the anterior lobe under produces growth hormone. Or it's not producing enough growth hormone. So the result will be a person that is really short, but with normal proportions.
Again, body proportions are normal, but the person is just going to be shorter than average.
Pituitary dwarfism can actually be inherited. Or, if there is some sort of injury or tumor that affects the pituitary, it can also affect the amount of growth hormone being released.
So sometimes, if this is detected in children while they're still growing, they can receive shots of artificial growth hormone, which will then increase the growth hormone levels, and help them grow to an average height. However this is very expensive. And it's also a big ethical debate. People don't think that artificial growth hormone should be used to treat these disorders.
So growth hormone disorders can be a result of too much or too little growth hormone being secreted into the body.
This lesson has been an overview on disorders associated with the growth hormone.
A condition in which growth hormone levels are too high at an age before growth plates ossify; this causes bones and other tissues to grow proportionally larger than average.
A condition in which growth hormone levels are too high after growth plates ossify; this causes bones to thicken and extremities to enlarge but bones cannot grow in length. The most prominent signs are enlarged facial features, hands and feet.
A condition in which growth hormones levels are too low at a young age and the person is proportionally smaller than normal.