Exercise 4: Endocrine System Physiology
Hormones and Metabolism
Activity 1: Determining the Baseline Metabolic Rates
1. Which rat had the fastest baseline metabolic rate? Normal rate
2. Why did the metabolic rates differ? Because of the different organs that were removed from the two other rats that would produce certain hormones
3. If an animal has been thyroidectomized, what hormone(s) would be missing from its blood? thyroxine
4. As a result of the missing hormone(s), what would the overall effect on the body and metabolism be? Thyroxine wouldn’t be released which helps maintain metabolism and body. So
5. How could you treat a thyroidectomized animal so that it functioned like a “normal” animal? I would assume giving it shots of thyroxine or t4, of course by measuring weight and figuring out exactly the right amount to keep it established.
6. If an animal has been hypophysectomized, what effect would you expect to see in the hormone levels in its body? The hormone levels would also be lowered
7. What would be the effect of a hypophysectomy on the metabolism of an animal? Metabolism would drop
Activity 2: Determining the Effect of Thyroxine on Metabolic Rate
1. What was the effect of thyroxine on the normal rat’s metabolic rate? How does it compare to the normal rat’s baseline metabolic rate? The metabolic rate went up, and was higher then the normal baseline
2. Why was this effect seen? Because it already has thyroxin and when you add more of it then it goes even quicker.
3. What was the effect of thyroxine on the thyroidectomized rat’s metabolic rate? How does it compare to the thyroidectomized rat’s baseline metabolic rate? It raised the rate, even though it wasn’t as high as the baseline one, it still help to try and balance it out
4. Why was this effect seen? Metabolic rate was raised to try and reach normal rates even though still lower then the baseline. It has its pituitary gland so some hormones are there.
5. What was the effect of thyroxine on the
Activity 1: Determining the Baseline Metabolic Rates
1. Which rat had the fastest baseline metabolic rate? Normal rate
2. Why did the metabolic rates differ? Because of the different organs that were removed from the two other rats that would produce certain hormones
3. If an animal has been thyroidectomized, what hormone(s) would be missing from its blood? thyroxine
4. As a result of the missing hormone(s), what would the overall effect on the body and metabolism be? Thyroxine wouldn’t be released which helps maintain metabolism and body. So
5. How could you treat a thyroidectomized animal so that it functioned like a “normal” animal? I would assume giving it shots of thyroxine or t4, of course by measuring weight and figuring out exactly the right amount to keep it established.
6. If an animal has been hypophysectomized, what effect would you expect to see in the hormone levels in its body? The hormone levels would also be lowered
7. What would be the effect of a hypophysectomy on the metabolism of an animal? Metabolism would drop
Activity 2: Determining the Effect of Thyroxine on Metabolic Rate
1. What was the effect of thyroxine on the normal rat’s metabolic rate? How does it compare to the normal rat’s baseline metabolic rate? The metabolic rate went up, and was higher then the normal baseline
2. Why was this effect seen? Because it already has thyroxin and when you add more of it then it goes even quicker.
3. What was the effect of thyroxine on the thyroidectomized rat’s metabolic rate? How does it compare to the thyroidectomized rat’s baseline metabolic rate? It raised the rate, even though it wasn’t as high as the baseline one, it still help to try and balance it out
4. Why was this effect seen? Metabolic rate was raised to try and reach normal rates even though still lower then the baseline. It has its pituitary gland so some hormones are there.
5. What was the effect of thyroxine on the