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Physio Ex 9.0

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REVIEW SHEET
EXERCISE 4
Endocrine System Physiology

NAME:
LAB TIME/DATE:

Metabolism
The following questions refer to Activity 1: Determining Baseline Metabolic Rates. 1. Which rat had the fastest baseline metabolic rate?
The normal rat had the fastest baseline metabolic rate.
2. Compare the baseline metabolic rates for the thyroidectomized rat and the normal rat and explain your results.
The normal rat’s baseline metabolic rate was faster than that of the thyroidectomized rat’s baseline metabolic rate. 3. Compare the baseline metabolic rates for the hypophysectomized rat and the normal rat and explain your results. The normal rat’s baseline metabolic rates were faster than that of the hypophysectomized rat’s baseline metabolic rate because it lacked thyroid-stimulating hormones. The following questions refer to Activity 2: Determining the Effect of Thyroxine on Metabolic Rate. 4. What effect did administering thyroxine have on each of the rats?

It caused the metabolic rate to increase in all three rats.

5. Explain why thyroxine had these effects.
It is a thyroid-stimulating hormone that causes more metabolism to occur.

The following questions refer to Activity 3: Determining the Effect of TSH on Metabolic Rate. 6. Was there a change in the metabolic rate of the thyroidectomized rat with the administration of TSH? Explain your results. There was no change in the metabolic rate. It stayed the same as the baseline metabolic rate.

7. Did the results for the thyroidectomized rat indicate hyperthyroidism or hypothyroidism? It indicated hypothyroidism since there is no longer any thyroid.

The following questions refer to Activity 4: Determining the Effect of Propylthiouracil on Metabolic Rate. 8. Describe the effect of administering propylthiouracil on each of the rats, and explain why it had this effect. It decreased the baseline metabolic rate in the normal and hypophysectomized rats. Propylthiouracil blocks the...