Endocrine System Physiology: Computer Simulation
NAME LAB TIME/DATE
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Endocrine System Physiology: Computer Simulation
Metabolism
The following questions refer to Activity 1: Determining Baseline Metabolic Rates.
1. Which rat had the fastest baseline metabolic rate? -------------------------The normal rat
2. Compare the baseline metabolic rates for the thyroidectomized rat and the normal rat and explain your results. The thyroidectomized rat had a lower baseline metabolic rate beause the removal of its thyroid gland prevented it from producing any thyroxine.
3. Compare the baseline metabolic rates for the hypophysectomized rat and the normal rat and explain your results. The hypophysectomized rat had a lower baseline metabolic rate because removal of the pituitary gland, or hypophysis, prevented TSH production.
r=>.
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?
The baseline metabolic rate increased in each rat.
5. Explain why thyroxine had these effects. The effect of thyroxine is to increase baseline metabolic rate.
The following questions refer to Activity 3: Determining the Effect ofTSH on Metabolic Rate. 6. Was there a change in the metabolic rate of the thyroidectomized rat with the administration ofTSH? Explain your results. __
No; there was no thyroid gland to be stimulated.
7. Did the results for the thyroidectomized
rat indicate hyperthyroidism
or hypothyroidism?
_H-'y'-'-p_o_th-'y_r_ol_·d_is_m
_
The following questions refer to Activity 4: Determining the Effect of Propylthiouracil on Metabolic Rate.
381
8. Describe the effect of administering propylthiouracil on each of the rats, and explain why it had this effect. It decreased
BMR in normal and hypophysectomized rats because propylthiouracil blocks the attachment of iodine to tyrosine residues and
interferes with the conversion of thyroxine to triiodothyronine.
9. Do
_
Endocrine System Physiology: Computer Simulation
Metabolism
The following questions refer to Activity 1: Determining Baseline Metabolic Rates.
1. Which rat had the fastest baseline metabolic rate? -------------------------The normal rat
2. Compare the baseline metabolic rates for the thyroidectomized rat and the normal rat and explain your results. The thyroidectomized rat had a lower baseline metabolic rate beause the removal of its thyroid gland prevented it from producing any thyroxine.
3. Compare the baseline metabolic rates for the hypophysectomized rat and the normal rat and explain your results. The hypophysectomized rat had a lower baseline metabolic rate because removal of the pituitary gland, or hypophysis, prevented TSH production.
r=>.
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?
The baseline metabolic rate increased in each rat.
5. Explain why thyroxine had these effects. The effect of thyroxine is to increase baseline metabolic rate.
The following questions refer to Activity 3: Determining the Effect ofTSH on Metabolic Rate. 6. Was there a change in the metabolic rate of the thyroidectomized rat with the administration ofTSH? Explain your results. __
No; there was no thyroid gland to be stimulated.
7. Did the results for the thyroidectomized
rat indicate hyperthyroidism
or hypothyroidism?
_H-'y'-'-p_o_th-'y_r_ol_·d_is_m
_
The following questions refer to Activity 4: Determining the Effect of Propylthiouracil on Metabolic Rate.
381
8. Describe the effect of administering propylthiouracil on each of the rats, and explain why it had this effect. It decreased
BMR in normal and hypophysectomized rats because propylthiouracil blocks the attachment of iodine to tyrosine residues and
interferes with the conversion of thyroxine to triiodothyronine.
9. Do