Question 1

Which of the following best describes a key difference between the endocrine and nervous systems in terms of their signaling mechanisms and effects?

Accepted Answer

The endocrine system releases hormones into the bloodstream that act on distant targets and have slower, longer-lasting effects.

Question 2

A patient is given RU486 (mifepristone) to induce abortion. What is the mechanism by which this drug acts?

Accepted Answer

It blocks progesterone receptors, preventing progesterone from maintaining the uterus.

Question 3

Which of the following hormones is lipid-soluble and requires a transport protein to travel in the bloodstream?

Accepted Answer

Thyroxine ($T_4$)

Question 4

A person is exposed to cholera toxin, which locks G-proteins in the activated state in intestinal epithelial cells. What is the physiological consequence of this?

Accepted Answer

Increased cAMP production leading to massive chloride, sodium, and water secretion into the intestinal lumen.

Question 5

Which of the following is an example of a hormone interaction where two hormones have opposite effects on the same physiological process?

Accepted Answer

Insulin and glucagon on glycogen metabolism

Question 6

A patient presents with symptoms of hyperglycemia, excessive thirst, and frequent urination. Laboratory tests reveal a deficiency of insulin. Which type of diabetes mellitus does this patient most likely have?

Accepted Answer

Type I diabetes mellitus

Question 7

Which hormone is responsible for stimulating uterine contractions during childbirth and milk ejection during breastfeeding, and is regulated by a positive feedback mechanism?

Accepted Answer

Oxytocin

Question 8

A patient with Cushing’s syndrome is likely to exhibit which of the following symptoms due to hypersecretion of glucocorticoids?

Accepted Answer

Redistribution of fat, spindly arms and legs, poor wound healing, and easy bruising

Question 9

Which of the following best explains the diabetogenic effect of excess human growth hormone ($hGH$)?

Accepted Answer

It raises blood glucose concentration, causing the pancreas to release insulin continually, which may lead to beta-cell burnout and diabetes mellitus.

Question 10

Which hormone is secreted by the adrenal cortex and is primarily responsible for increasing sodium reabsorption in the kidneys, thereby raising blood pressure?

Accepted Answer

Aldosterone

Question 11

A patient with hypothyroidism is likely to present with which of the following symptoms?

Accepted Answer

Sensitivity to cold, low body temperature, weight gain, and mental dullness

Question 12

Which of the following hormones is produced by alpha cells in the pancreatic islets and acts to increase blood glucose levels?

Accepted Answer

Glucagon

Question 13

Which hormone is released in response to low blood calcium levels and acts to increase calcium by stimulating osteoclast activity and promoting formation of calcitriol?

Accepted Answer

Parathyroid hormone (PTH)

Question 14

Which of the following is a water-soluble hormone that acts via a second messenger system involving cyclic AMP ($cAMP$)?

Accepted Answer

Epinephrine

Question 15

A patient is experiencing symptoms of seasonal affective disorder (SAD) during winter months. Which hormone is most likely involved, and what is a recommended therapy?

Accepted Answer

Melatonin; exposure to bright artificial light

Question 16

Which hormone is produced by the anterior pituitary and stimulates the synthesis and secretion of thyroid hormones ($T_3$ and $T_4$)?

Accepted Answer

Thyroid-stimulating hormone (TSH)

Question 17

Which hormone is secreted by the pineal gland and is responsible for setting the biological clock?

Accepted Answer

Melatonin

Question 18

A patient with Addison’s disease is likely to present with which of the following symptoms?

Accepted Answer

Hypoglycemia, muscle weakness, low blood pressure, dehydration, and skin darkening

Question 19

Which hormone is released by the posterior pituitary and acts to decrease urine production, decrease sweating, and increase blood pressure?

Accepted Answer

Antidiuretic hormone (ADH)

Question 20

A patient is prescribed ibuprofen for pain and inflammation. What is the mechanism by which this drug acts?

Accepted Answer

It inhibits a key enzyme in prostaglandin synthesis without affecting leukotriene synthesis.

The Endocrine System: Structure, Function, and Regulation

Study Guide - Practice Questions

Study Guide - Flashcards