16. The Endocrine System

A rise in free T3 and T4 would be expected to produce a(n) ______ in TRH and TSH secretion. A decrease in free T3 and T4 would be expected to produce a(n) _____ a(n)_____in TRH and TSH secretion.

Which of the following statements correctly describes the role of parathyroid hormone?

a. Parathyroid hormone regulates the metabolic rate.

b. Parathyroid hormone increases the blood calcium ion concentration.

c. Parathyroid hormone decreases the blood sodium ion concentration.

d. Parathyroid hormone causes water retention by the kidneys.

Which of the following is not an effect of aldosterone?

a. Increased excretion of hydrogen ions from the fluid in the kidneys

b. Increased retention of sodium ions from the fluid in the kidneys

c. Increased retention of potassium ions from the fluid in the kidneys

d. Increased retention of water from the fluid in the kidneys

Cortisol is:

a. A potent inhibitor of the inflammatory response.

b. An important part of the stress response.

c. Both a and b are correct.

d. Neither a nor b is correct.

Which of the following hormones is not an integral part of the stress response?

a. Epinephrine

b. Cortisol

c. Insulin

d. Glucagon

Explain how insulin and glucagon are antagonists.

Type 1 diabetes mellitus is characterized by______, and type 2 diabetes mellitus is characterized by_____.

a. hypoglycemia; destruction of the pancreatic β cells

b. destruction of the pancreatic β cells; destruction of the pancreatic α cells

c. insulin resistance; destruction of the pancreatic β cells

d. destruction of the pancreatic β cells; insulin resistance

Match the following hormones with their correct descriptions. 

Leptin      

Atrial natriuretic peptide      

Melatonin      

Estrogens      

Erythropoietin      

Testosterone

a. Produced by the pineal gland; regulates the sleep/wake cycle

b. Produced by the kidneys; regulates red blood cell production

c. Produced by the heart; promotes sodium ion loss in the kidneys and vasodilation

d. Produced by the testes; promotes androgenic and anabolic actions

e. Produced by adipose tissue; promotes satiety

f. Produced by the ovaries; regulate the menstrual cycle and the development of secondary sex characteristics

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Both ADH and aldosterone increase the amount of water in the body and decrease the solute concentration of the blood.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Thyroid hormones and insulin maintain blood glucose concentration during fasting.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Insulin secretion rises during feeding; growth hormone and glucagon are secreted during feeding if protein is present in the meal.

Predict the effects of a pancreatic tumor that secretes insulin. How would the effects change if the tumor secreted glucagon instead?

Females with hormone-secreting tumors of the adrenal cortex occasionally develop male secondary sex characteristics. Explain why this may happen.

A new diet guru claims hypersecretion of cortisol is the reason why so many people are obese. He is marketing a dietary supplement that is supposedly able to block cortisol secretion and lead to weight loss. How would cortisol hypersecretion cause weight gain? Would blocking normal cortisol secretion lead to weight loss? Why or why not?

Let's say that the dietary supplement in question 2 actually works and successfully blocks cortisol secretion. Could this drug potentially be harmful? Predict its effects on overall homeostasis.