Module 2

1. Module 2

1.16. Page 5

Lesson 2

Module 2—The Endocrine System

Watch and Listen

To explore some interesting concepts about human growth hormone, watch the following segments of “The Hypothalamus and Pituitary Gland: The Master Complex,” and make some additional notes for your course folder. You may need to enter a username and password to access these videos. Contact your teacher for this information.

“Human Growth Hormone”
“Bio Challenge: Growth Hormone Imbalances”
“Bio Discovery: Growth Hormone Deficiency”
“Bio Review: Growth Hormone Therapy”
“Bio STS: Synthetic Human Growth Hormone”
“Bio Bit: Bovine Growth Hormone

Try This

TR 1. Emily’s husband has become very concerned about some of the symptoms she is currently exhibiting, and the inability of several physicians to diagnose and treat whatever is wrong. One doctor figured out what was wrong, but he could only provide Emily and her husband with limited information. Emily’s husband has decided to write to a newspaper columnist who specializes in answering questions about health.

Pretend that you are Dr. Stoppain, who answers health-related questions in a daily newspaper column. You received the following letter, and your task is to write a response by defining the health condition, explaining the symptoms of the condition, outlining possible treatment, and answering the writer’s questions.

Dear Dr. Stoppain,

My wife is 30 years old. For the last several years she has suffered from numerous violent headaches. She has sought help from several different doctors, who suggested various treatments. None of these worked. Then, she noticed that her vision was blurred, particularly off to the sides. She went to see an eye doctor, who suggested that she had acromegaly and referred her to an endocrine specialist, who confirmed the suspicion. We know next to nothing about this condition. What causes it? Is treatment successful? Will acomegaly shorten her life?

Concerned Husband

Check your work.

Try This Answers

The following is a possible reply from Dr. Stoppain. Check your response to see whether you have outlined the cause of acromegaly, described at least two symptoms of the disorder, explained the ones that the husband mentioned in his letter (violent headaches, loss of peripheral vision), and outlined how acromegaly may be treated.

Dear Concerned Husband,

Acromegaly is a rare condition that is linked to a tumour of the pituitary gland, which causes the anterior pituitary gland to produce too much human growth hormone. The pituitary gland lies on the underside of the brain at a level approximately in line with the bridge of the nose.

In children, human growth hormone allows for the attainment of height programmed by the genes. The bones lengthen at growth plates on their ends. At the end of our growing period, these plates seal and no more growth is possible. In adults, too much growth hormone leads to radical changes in body appearance, but the changes occur so slowly that they often go unrecognized. Hands and feet become thick and wide. The forehead enlarges and the jaw juts out. Spaces appear between the teeth. Blood pressure rises and the heart enlarges.

Headaches are a common sign of a pituitary tumour. Vision problems also arise because the pituitary gland lies behind the optic nerve, and a pituitary tumour presses on the nerve and interferes with transmission of visual images to the brain.

Diagnosis of acromegaly is established by measuring growth hormone levels in the blood. A scan of the brain can clearly detect the presence of a tumour.

Treatment consists of removal of the tumour, which can often be done with instruments passed through the nose or palate. When surgery is not feasible, medicines can dampen the production of growth hormone. Sometimes, focused radiation therapy can shrink the tumour.

Your wife might not have any noticeable physical changes associated with acromegaly. Now that the condition has been proven, she can undergo appropriate therapy. Her life will not be shortened.

Dr. Stoppain

Going Beyond

Have you ever considered the problems that people of short stature encounter? If you have an opportunity to watch a rerun of a documentary called Short and Male, you should do so. It originally aired on CTV on Saturday, May 24, 2008. Thought-provoking questions are raised and the risks and benefits of hGH therapy are addressed. You might find it on the Internet by using search words such as “CTV,” “W5,” or “short and male.”