Question 1

Which of the following best describes the mechanism of action for water-soluble hormones such as epinephrine?

Accepted Answer

They bind to receptors on the outer surface of the cell membrane, activating a second messenger system.

Question 2

A patient presents with low blood calcium levels. Which hormone is most likely to be secreted in response, and what is its primary action?

Accepted Answer

Parathyroid hormone (PTH); stimulates osteoclasts to release calcium from bone.

Question 3

Which of the following is a correct sequence for the synthesis and release of thyroid hormones?

Accepted Answer

Iodine enters the follicle cell → Thyroglobulin is synthesized → Iodinated tyrosines are coupled → T3 and T4 are released into the blood

Question 4

Which hormone is released from the anterior pituitary in response to corticotropin-releasing hormone (CRH) from the hypothalamus?

Accepted Answer

Adrenocorticotropic hormone (ACTH)

Question 5

A patient with a tumor in the zona glomerulosa of the adrenal cortex would most likely have abnormal levels of which hormone?

Accepted Answer

Aldosterone

Question 6

Which of the following best explains why steroid hormones generally have a slower onset of action compared to peptide hormones?

Accepted Answer

Steroid hormones act by direct gene activation, which involves transcription and translation.

Question 7

Which of the following is NOT a typical effect of glucocorticoids during prolonged stress?

Accepted Answer

Decreased blood glucose levels

Question 8

Which hormone is secreted by the posterior pituitary and is essential for water reabsorption in the kidneys?

Accepted Answer

Antidiuretic hormone (ADH)

Question 9

A patient with Type I diabetes mellitus is unable to produce which hormone, and what is the primary effect on blood glucose?

Accepted Answer

Insulin; blood glucose increases

Question 10

Which of the following best describes the role of tropic hormones?

Accepted Answer

They stimulate other endocrine glands to release their hormones.

Question 11

Which hormone is primarily responsible for the development of secondary sex characteristics in males?

Accepted Answer

Testosterone

Question 12

Which of the following best explains why T3 and T4 are transported in the blood bound to proteins?

Accepted Answer

They are lipid-soluble and do not dissolve well in plasma.

Question 13

Which of the following scenarios is an example of humoral stimulus for hormone release?

Accepted Answer

Increased blood glucose stimulates insulin release from the pancreas.

Question 14

Which hormone is secreted by the pineal gland and is associated with regulation of circadian rhythms?

Accepted Answer

Melatonin

Question 15

Which of the following is a correct statement about the relationship between the hypothalamus and the posterior pituitary?

Accepted Answer

The hypothalamus synthesizes hormones that are stored and released by the posterior pituitary.

Question 16

Which hormone is released in response to increased blood potassium levels and acts to restore electrolyte balance?

Accepted Answer

Aldosterone

Question 17

Which of the following best describes the effect of insulin on muscle cells?

Accepted Answer

It stimulates glucose uptake and protein synthesis.

Question 18

Which hormone is responsible for stimulating uterine contractions during childbirth?

Accepted Answer

Oxytocin

Question 19

A patient with hypoparathyroidism would most likely experience which of the following symptoms?

Accepted Answer

Muscle spasms due to low blood calcium

Question 20

Which of the following best explains why the effects of catecholamines (epinephrine and norepinephrine) are short-lived compared to steroid hormones?

Accepted Answer

Catecholamines are rapidly degraded by enzymes in the blood.

The Endocrine System: Structure, Function, and Regulation

Study Guide - Practice Questions