Metabolism and Hormonal Regulation in Endocrinology

Lab Report Pre-lab Quiz Results You scored 100% by answering 6 out of 6 questions correctly. 1 Which of the following statements about metabolism is false ? You correctly answered: All of the energy from metabolism is ultimately stored in the chemical bonds of ATP. 2 Thyroxine is You correctly answered: the most important hormone for maintaining the metabolic rate and body temperature. 3 Thyroid-stimulating hormone (TSH) is You correctly answered: produced in the pituitary gland. 4 An injection of TSH to an otherwise normal animal will cause which of the following? You correctly answered: goiter development. 5 Thyrotropin-releasing hormone (TRH) is You correctly answered: secreted by the hypothalamus. 6 Which of the following statements is true? You correctly answered: The hypothalamus primarily secretes tropic hormones that stimulate the secretion of other hormones. Experiment Results Predict Questions 1 Predict Question 1: Make a prediction about the basal metabolic rate (BMR) of the remaining rats compared with the BMR of the normal rat you just measured. Your answer: The BMR of both remaining rats will be lower than the normal rat's BMR. 2 Predict Question 2: What do you think will happen after you inject thyroxine into the three rats? Your answer: The normal rat will become hyperthyroidic and develop a goiter. 3 Predict Question 3: What do you think will happen after you inject TSH into the three rats? Your answer: The normal rat will become hyperthyroidic and develop a goiter. 4 Predict Question 4: Propylthiouracil (PTU) is a drug that inhibits the production of thyroxine by blocking the attachment of iodine to tyrosine residues in the follicle cells of the thyroid gland (iodinated tyrosines are linked together to form thyroxine). What do you think will happen after you inject PTU into the three rats? Your answer: The thyroidectomized rat will become hypothyroidic and develop a goiter. Stop & Think Questions 1 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 432 ml O /hr.2 2 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 1734 ml O /kg/hr. 2 3 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 378 ml O /hr.2 4 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 1542 ml O /kg/hr. 2 5 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 372 ml O /hr.2 6 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 1524 ml O /kg/hr. 2 7 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800). The normal rat is You correctly answered: euthyroid. 8 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800). The thyroidectomized (Tx) rat is You correctly answered: hypothyroid. 9 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800). The hypophysectomized (Hypox) rat is You correctly answered: hypothyroid. 10 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 56 ml O /hr.2 11 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 132 ml O /kg/hr. 2 12 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 54 ml O /hr.2 13 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 654 ml O /kg/hr. 2 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 675 ml O /hr.2 15 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 866 ml O /kg/hr. 2 16 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the thyroxine injection. The normal rat is Your answer: hypothyroid. Correct answer: hyperthyroid. 17 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the thyroxine injection. The thyroidectomized (Tx) rat is Your answer: hypothyroid. Correct answer: hyperthyroid. 18 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the thyroxine injection. The hypophysectomized (Hypox) rat is Your answer: hypothyroid. Correct answer: hyperthyroid. 19 Which of the rats developed a goiter after injection with thyroxine? You correctly answered: None of the rats developed a goiter with this injection. 20 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 9765 ml O /hr.2 21 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 276 ml O /kg/hr. 2 22 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 754 ml O /hr.2 23 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 23 ml O /kg/hr. 2 24 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 657 ml O /hr.2 25 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 44 ml O /kg/hr. 2 26 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the TSH injection. The normal rat is You correctly answered: hyperthyroid. 27 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the TSH injection. The thyroidectomized (Tx) rat is Your answer: hyperthyroid. Correct answer: hypothyroid. 28 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the TSH injection. The hypophysectomized (Hypox) rat is You correctly answered: hyperthyroid. 29 Which of the rats did not develop a goiter after injection with TSH? Your answer: the normal rat. Correct answer: the thyroidectomized rat. 30 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 12 ml O /hr.2 31 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 343 ml O /kg/hr. 2 32 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 675 ml O /hr.2 33 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 3 ml O /kg/hr. 2 34 Calculate the oxygen consumption per hour for this rat using the following equation. ml O 2 consumed/1 minute x 60 minutes/hour = ml O /hour 2 Enter the oxygen consumption per hour. You answered: 65 ml O /hr.2 35 Now that you have calculated the oxygen consumption per hour for this rat, you can calculate the metabolic rate per kilogram of body weight with the following equation (note that you need to convert the weight data from grams to kilograms to use this equation). Metabolic rate = (ml O /hr)/(weight in kg) = ml O /kg/hr 2 2 Enter the metabolic rate. You answered: 987 ml O /kg/hr. 2 36 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the PTU injection. The normal rat is You correctly answered: hypothyroid. 37 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the PTU injection. The thyroidectomized (Tx) rat is You correctly answered: hypothyroid. 38 Judging from their basal metabolic rates (an indicator of thyroid function), categorize the rats as hypothyroid (low thyroid levels; BMR below 1600), euthyroid ("good," or normal, thyroid levels; BMR = 1650-1750), or hyperthyroid (high thyroid levels; BMR above 1800) after the PTU injection. The hypophysectomized (Hypox) rat is You correctly answered: hypothyroid. 39 Which of the rats developed a goiter after injection with PTU? You correctly answered: the normal rat. Experiment Data Post-lab Quiz Results You scored 100% by answering 7 out of 7 questions correctly. 1 How would you treat a thyroidectomized animal so that it functions like a "normal" animal? You correctly answered: Provide the animal T supplements. 4 2 As a result of the missing hormone(s) in the hypophysectomized rat, what would be an expected symptom? You correctly answered: decreased basal metabolic rate. 3 An injection of thyroxine to an otherwise normal rat will cause which of the following? You correctly answered: hyperthyroidism. 4 Why didn't any of the rats develop a goiter after thyroxine injection? You correctly answered: In all cases, TSH levels were not elevated by the thyroxine injection. 5 Why did the normal rat develop a palpable goiter with the TSH injection? You correctly answered: The TSH receptors on the thyroid gland were excessively stimulated. 6 An injection of propylthiouracil to an otherwise normal animal will cause which of the following? You correctly answered: goiter development. 7 Why did the normal rat develop a palpable goiter with the propylthiouracil injection? You correctly answered: The injection decreased the negative feedback mechanism on TSH. Review Sheet Results 1 Part 1: Determining the Basal Metabolic Rates Which rat had the fastest basal metabolic rate (BMR)? Your answer: The normal rat. 2 Why did the metabolic rates differ between the normal rat and the surgically altered rats? How well did the results compare with your prediction? Your answer: The organs that play an important role for maintaining the BMR were removed in the other rats. 3 If an animal has been thyroidectomized, what hormone(s) would be missing in its blood? Your answer: Thyroxine. 4 If an animal has been hypophysectomized, what effect would you expect to observe in the hormone levels in its body? Your answer: The animal would lose TSH so nothing could stimulate the the thyroid to secret thyroxine. 5 Part 2: Determining the Effect of Thyroxine on Metabolic Rate What was the effect of thyroxine injections on the normal rat's BMR? Your answer: The rat became hyperthyroidic. 6 What was the effect of thyroxine injections on the thyroidectomized rat's BMR? How does the BMR in this case compare with the normal rat's BMR? Was the dose of thyroxine in the syringe too large, too small, or just right? Your answer: The BMR was increased to 1935. Which is lower than normal but it is higher than normal without drugs because the BMR was over 1800 thyroxine so the dose was too big. 7 What was the effect of thyroxine injections on the hypophysectomized rat's BMR? How does the BMR in this case compare with the normal rat's BMR? Was the dose of thyroxine in the syringe too large, too small, or just right? Your answer: The BMR was raised to 1895, but it is not as high as the thyroidectimized or normal rats with thyroxine because it is over 1800 so the dose was too big. 8 Part 3: Determining the Effect of TSH on Metabolic Rate What was the effect of thyroid-stimulating hormone (TSH) injections on the normal rat's BMR? Your answer: The normal rat was hyperthyroidic. 9 What was the effect of TSH injections on the thyroidectomized rat's BMR? How does the BMR in this case compare with the normal rat's BMR? Why was this effect observed? Your answer: It didn't raise the BMR, it remained in hypothyroid under 1600. 10 What was the effect of TSH injections on the hypophysectomized rat's BMR? How does the BMR in this case compare with the normal rat's BMR? Was the dose of TSH in the syringe too large, too small, or just right? Your answer: The dose was too large because it became 1918 below the normal but it went to hyperthyroid. 11 Part 4: Determining the Effect of Propylthiouracil on Metabolic Rate What was the effect of propylthiouracil (PTU) injections on the normal rat's BMR? Why did this rat develop a palpable goiter? Your answer: The administration of the PTU injection into the normal rat resulted in the decrease on the BMR. The palpable goiter was developed because of the accumulations of antecedents to thyroxine. 12 What was the effect of PTU injections on the thyroidectomized rat's BMR? How does the BMR in this case compare with the normal rat's BMR? Why was this effect observed? Your answer: The effect of the PTU injections on the throidectomized rat was not visible because there is no thyroid gland present in this rat to be stimulated. 13 What was the effect of PTU injections on the hypophysectomized rat's BMR? How does the BMR in this case compare with the normal rat's BMR? Why was this effect observed? Your answer: The effect of PTU injections into the hypophysectomized rat is not visible as there is no pituitary gland present in this rat to be stimulated.