PhysioEx Exercise 4 Activity 1

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 1/13 PhysioEx Lab Report Exercise 4: Endocrine System Physiology Activity 1: Metabolism and Thyroid Hormone Name: Shanice Simpson Date: 20 March 2024 Session ID: session-d1b19316-80bd-8f46-8892-b01c987c8c23 Pre-lab Quiz Results You scored 100% by answering 6 out of 6 questions correctly. Experiment Results Predict Questions 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. 1 Thyroxine is You correctly answered: the most important hormone for maintaining the metabolic rate and body temperature. 2 Thyroid-stimulating hormone (TSH) is You correctly answered: produced in the pituitary gland. 3 An injection of TSH to an otherwise normal animal will cause which of the following? You correctly answered: goiter development. 4 Thyrotropin-releasing hormone (TRH) is You correctly answered: secreted by the hypothalamus. 5 Which of the following statements is true? You correctly answered: The hypothalamus primarily secretes tropic hormones that stimulate the secretion of other hormones. 6 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. 1

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 2/13 Stop & Think Questions Your answer: The BMR of both remaining rats will be lower than the normal rat's BMR. 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 but will not develop a goiter. 2 Predict Question 3: What do you think will happen after you inject TSH into the three rats? Your answer: The thyroidectomized rat will become hyperthyroidic and develop a goiter. 3 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 normal rat will become hyperthyroidic and develop a goiter. 4 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 432 ml O /hr. 1 2 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 Enter the metabolic rate. You answered: 1734.94 ml O /kg/hr. 2 2 2 2 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 378 ml O /hr. 3 2 2 2

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 4/13 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. 9 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 492 ml O /hr. 10 2 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 Enter the metabolic rate. You answered: 1975.90 ml O /kg/hr. 11 2 2 2 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 468 ml O /hr. 12 2 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 Enter the metabolic rate. You answered: 1902.44 ml O /kg/hr. 13 2 2 2

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 5/13 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 468 ml O /hr. 14 2 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 Enter the metabolic rate. You answered: 1902.44 ml O /kg/hr. 15 2 2 2 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 You correctly answered: hyperthyroid. 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 thyroidectomized (Tx) rat is You correctly answered: 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 hypophysectomized (Hypox) rat is 18

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 7/13 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 462 ml O /hr. 24 2 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 Enter the metabolic rate. You answered: 1878.05 ml O /kg/hr. 25 2 2 2 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. 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 thyroidectomized (Tx) rat is You correctly answered: hypothyroid. 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 hypophysectomized (Hypox) rat is 28

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 8/13 You correctly answered: hyperthyroid. Which of the rats did not develop a goiter after injection with TSH? You correctly answered: the thyroidectomized rat. 29 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 378 ml O /hr. 30 2 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 Enter the metabolic rate. You answered: 1518.07 ml O /kg/hr. 31 2 2 2 Calculate the oxygen consumption per hour for this rat using the following equation. ml O consumed/1 minute x 60 minutes/hour = ml O /hour Enter the oxygen consumption per hour. You answered: 378 ml O /hr. 32 2 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 Enter the metabolic rate. You answered: 1536.59 ml O /kg/hr. 33 2 2 2

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 10/13 Experiment Data Rat Weight (g) ml O /min ml O /hr BMR (ml O /kg/hr) Palpation Injected Normal 249 7.2 432.00 1734.94 No Mass none Tx 246 6.3 378.00 1536.59 No Mass none Hypox 246 6.3 378.00 1536.59 No Mass none Normal 249 8.4 504.00 2024.10 No Mass thyroxine Tx 246 7.8 468.00 1902.44 No Mass thyroxine Hypox 246 7.8 468.00 1902.44 No Mass thyroxine Normal 249 8.1 486.00 1951.81 Mass TSH Tx 246 6.3 378.00 1536.59 No Mass TSH Hypox 246 7.7 462.00 1878.05 Mass TSH Normal 249 6.3 378.00 1518.07 Mass PTU Tx 246 6.3 378.00 1536.59 No Mass PTU Hypox 246 6.3 378.00 1536.59 No Mass PTU Post-lab Quiz Results You scored 100% by answering 7 out of 7 questions correctly. You correctly answered: hypothyroid. Which of the rats developed a goiter after injection with PTU? You correctly answered: the normal rat. 39 2 2 2 How would you treat a thyroidectomized animal so that it functions like a "normal" animal? You correctly answered: Provide the animal T supplements. 1 4 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. 2 An injection of thyroxine to an otherwise normal rat will cause which of the following? You correctly answered: hyperthyroidism. 3 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. 4

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 11/13 Review Sheet Results 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. 5 An injection of propylthiouracil to an otherwise normal animal will cause which of the following? You correctly answered: goiter development. 6 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. 7 Part 1: Determining the Basal Metabolic Rates Which rat had the fastest basal metabolic rate (BMR)? Your answer: The normal rat injected with thyroxine. 1 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 surgically altered rats could not produce specific hormones since they no longer have either a thyroid or pituitary gland. So, my prediction was correct. 2 If an animal has been thyroidectomized, what hormone(s) would be missing in its blood? Your answer: Thyroxine. 3 If an animal has been hypophysectomized, what effect would you expect to observe in the hormone levels in its body? Your answer: Due to the removal of the pituitary gland, TSH levels will be absent, resulting in a decline in metabolic rate. 4 Part 2: Determining the Effect of Thyroxine on Metabolic Rate What was the effect of thyroxine injections on the normal rat's BMR? 5

3/20/24, 11:06 AM PhysioEx Exercise 4 Activity 1 https://media.pearsoncmg.com/bc/bc_0media_ap/physioex/10/ex4/act1/ 13/13 The metabolic rate was increased to 1,878.05 which was higher than the normal rat's BMR. It has a pituitary gland, so some hormones are still there. The dose of the TSH in the syringe was too large. 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: It slowed the metabolic rate, compared to the normal baseline. PTU inhibits the production of thyroxine. That's why this rat developed a palpable goiter. 11 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 metabolic rate of this rat was reduced due to the absence of a thyroid gland, resulting in lesser impact from the injections. 12 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 on the hypophysectomized rat's BMR was not visible because the rat was missing the pituitary gland. 13