How does growth hormone regulate various body functions in adults, and what could cause the excess secretion of growth hormone?
Case Study 1:
Atherosclerosis is narrowing of arteries caused by the accumulation of fatty deposits on the arterial walls.
On June 22, 2002 the St. Louis Cardinals were preparing for their upcoming baseball game against the Chicago cubs. Concern arose when their prized pitcher, 33-year old Darryl Kile did not show up for practice. Soon after, he was found still in his hotel room where he had suddenly died in his sleep (New York Times, 2002). It was discovered that the cause of death was related to three of his coronary arteries being 80-90% blocked as a result of atherosclerosis (New York Times, 2002), which ultimately caused him to undergo a heart attack.
Answer the following assignment questions:
- Why would atherosclerosis result in a heart attack? Provide a brief explanation based on how the heart functions.
- How are arteries different from veins and capillaries? Describe the functions of both arteries and veins.
- Vertebrates and some invertebrates have a closed circulatory system. Explain the advantage of having a closed circulatory system over an open circulatory system?
- Briefly explain how the lymphatic system is associated with the circulatory system?
- Describe one disease that affects the lymphatic vessels similarly to the way that atherosclerosis affects the arteries?
Case Study 2:
Cigarette smoking remains the leading preventable cause of death in the United States, causing an estimated 438,000 deaths – or about 1 out of every 5 – each year (National Cancer Institute, 2008).
Mr. Amos is now 57 years old and has been smoking for the past 30 years of his life. A recent doctor’s visit reveals that Mr. Amos has stage 3 lung cancer, characterized by his symptoms of nagging chest pain, fatigue, coughing up blood, substantial weight loss, and increased carbon dioxide levels in his blood. The doctor informed Mr. Amos that had he quit his smoking habit several years ago, he would have reduced his risk for developing lung cancer later in life. Mr. Amos immediately begins treatment for the lung cancer that has metastasized to his lymph nodes.
Answer the following assignment questions:
- What main components in cigarettes affect the respiratory system? Explain their effects on specific organs, cells and/or processes in the respiratory system.
- There are alternate mechanisms of transporting carbon dioxide (CO2) and oxygen (O2 ) in the blood. Explain how smoking might lead to increased levels of carbon dioxide in the blood.
- Can smoking affect other organ systems of the body? Give specific examples and briefly explain your answer.
- How can you correlate cellular respiration with the respiratory system?
- Does smokeless tobacco present a reduced risk for lung cancer and other smoking associated diseases? Provide evidence for your answer.
Case Study 3:
Gigantism is abnormally large growth during childhood caused by excess growth hormone secreted by the anterior pituitary gland.
Robert Wadlow, born on February 22, 1918, weighed a normal eight pounds, six ounces. However, by the time Robert reached the age of six months old, he weighed 30 pounds (Hamilton, 1993). Within only a year, his weight rose to 62 pounds, more than double the normal weight of a baby at 18 months. Aside from his weight, Robert continued to grow at an astounding rate, reaching six feet, two inches and 195 pounds by the time he was eight years old. Robert’s unique size was attributed to an over active pituitary gland, which produced much higher than normal levels of growth hormone. At the time of his death in July 1940 at the age of 22, Robert had reached a height of 8 feet 11.1 inches and weighed 485 pounds (Hamilton, 1993).
Answer the following assignment questions:
- How does growth hormone regulate various body functions in adults, and what could cause the excess secretion of growth hormone?
- Discuss the relationship between growth hormone and insulin, and are there complications associated with their interaction?
- Why is gigantism usually more difficult to treat than dwarfism?
- Give examples of two other hormones secreted by the pituitary, and briefly describe how they specifically affect other organ systems of the body?
- Some athletes have resorted to the illegal use of anabolic steroids to increase strength and muscle size. How are anabolic steroids different from growth hormone? Briefly explain your answer.
