Question 1

Which of the following best describes the mechanism by which steroid hormones exert their effects on target cells?

Accepted Answer

They bind to intracellular receptors and directly influence gene expression.

Question 2

A patient presents with low blood calcium levels. Which hormone is most likely deficient, and what is its primary action?

Accepted Answer

Parathyroid hormone (PTH); increases blood calcium by acting on bone and kidneys

Question 3

Which hormone is secreted by the zona fasciculata of the adrenal cortex, and what is its main function?

Accepted Answer

Cortisol; regulates body processes during long-term stress

Question 4

A person experiencing dehydration will have increased secretion of which hormone, and what is its effect on the kidneys?

Accepted Answer

Antidiuretic hormone (ADH); enhances water reabsorption by collecting duct cells

Question 5

Which of the following equations correctly represents the conversion of thyroxine (T4) to its active form (T3) in target cells?

Accepted Answer

$$\mathrm{T4} \longrightarrow \mathrm{T3}$$

Question 6

Which hormone is released during the fight or flight response and what is its primary effect?

Accepted Answer

Epinephrine; increases heart rate and blood flow to muscles

Question 7

A patient with hyperthyroidism is likely to have elevated levels of which hormone, and what is its effect on metabolism?

Accepted Answer

Thyroxine (T4); increases cellular metabolism

Question 8

Which hormone is responsible for stimulating milk production in mammary glands?

Accepted Answer

Prolactin (PRL)

Question 9

If a person has a deficiency in insulin, which of the following will most likely occur?

Accepted Answer

Blood glucose concentration will increase

Question 10

Which of the following best describes the difference between pure endocrine glands and endocrine tissues?

Accepted Answer

Pure endocrine glands only produce hormones, while endocrine tissues are part of organs with other functions

Question 11

Which hormone is secreted by the adrenal cortex's zona glomerulosa, and what is its primary action?

Accepted Answer

Aldosterone; regulates salt balance by acting on nephrons

Question 12

Which hormone is secreted by parafollicular cells of the thyroid, and what is its effect?

Accepted Answer

Calcitonin; increases Ca++ uptake into bone, lowering blood Ca++

Question 13

Which hormone is produced by the hypothalamus and stored in the posterior pituitary, and what is its function?

Accepted Answer

Oxytocin; stimulates uterine contractions and milk ejection

Question 14

Which of the following hormones is derived from cholesterol?

Accepted Answer

Testosterone

Question 15

A patient with a tumor in the anterior pituitary may have abnormal levels of which hormone that stimulates the thyroid gland?

Accepted Answer

Thyroid Stimulating Hormone (TSH)

Question 16

Which hormone is secreted by α-cells in the pancreatic islets, and what is its effect?

Accepted Answer

Glucagon; increases blood glucose concentration

Question 17

Which hormone is secreted by the corpus luteum and what is its primary function?

Accepted Answer

Progesterone; prepares the uterus for implantation

Question 18

Which hormone is released by the heart and what is its effect on blood pressure?

Accepted Answer

Atrial natriuretic peptide (ANP); lowers blood pressure by promoting sodium excretion

Question 19

Which hormone is secreted by the kidney and stimulates red blood cell production?

Accepted Answer

Erythropoietin (EPO)

Question 20

Which hormone is released by the duodenum and stimulates the release of bile from the gallbladder?

Accepted Answer

Cholecystokinin (CCK)

The Endocrine System: Structure, Function, and Hormones

Study Guide - Practice Questions