1a. Glucose can be released from the liver and transported to many other tissues where it is taken up and induces a variety of biological effects. Glucose concentrations in animals range between 40 and 150 mg/100 mL. Based on this information, would you consider glucose to be a hormone? Why or why not?
b. Plasma concentrations of LH increase in males following removal of both testes. If the castrated male is then injected with testosterone, concentrations of LH fall to levels observed before removal of the testes. Explain these results based on your understanding of how endocrine systems are regulated.
c. Suppose you measure plasma concentrations of testosterone in bull elk throughout the year and discover that concentrations increase during the rutting season. You conclude that this is due to increased secretion by the testes. Is this a valid conclusion? Why or why not?
1a. Glucose can be released from the liver and transported to many other tissues where it is taken up and induces a variety of biological effects. Glucose concentrations in animals range between 40 and 150 mg/100 mL. Based on this information, would you consider glucose to be a hormone? Why or why not?
b. Plasma concentrations of LH increase in males following removal of both testes. If the castrated male is then injected with testosterone, concentrations of LH fall to levels observed before removal of the testes. Explain these results based on your understanding of how endocrine systems are regulated.
c. Suppose you measure plasma concentrations of testosterone in bull elk throughout the year and discover that concentrations increase during the rutting season. You conclude that this is due to increased secretion by the testes. Is this a valid conclusion? Why or why not?
