Question 1

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

Accepted Answer

Exocrine glands secrete substances into ducts or onto surfaces, while endocrine glands release hormones directly into the bloodstream.

Question 2

A patient presents with high levels of thyroid-stimulating hormone (TSH) in their blood. What is the most likely explanation?

Accepted Answer

The patient has an underactive thyroid gland (hypothyroidism).

Question 3

Which hormone is released by the adrenal cortex and is responsible for stimulating sodium conservation and potassium elimination?

Accepted Answer

Aldosterone

Question 4

Which of the following hormones is a peptide hormone released by pancreatic beta cells after a meal, and what is its primary effect?

Accepted Answer

Insulin; accelerates glucose uptake by target cells

Question 5

Which mechanism allows water-soluble hormones like catecholamines and peptide hormones to exert their effects on target cells?

Accepted Answer

They bind to extracellular receptors on the plasma membrane, triggering second messenger systems.

Question 6

Which of the following is a correct sequence for the second messenger pathway involving cAMP?

Accepted Answer

Hormone binds receptor → G protein activates adenylate cyclase → ATP is converted to cAMP

Question 7

Which hormone is secreted by the parathyroid glands in response to low blood calcium, and what is its primary action?

Accepted Answer

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

Question 8

Which of the following best explains the process of amplification in hormone signaling?

Accepted Answer

A single hormone molecule binds to a receptor, resulting in the production of thousands of second messenger molecules.

Question 9

Which hormone is produced by the pineal gland and is involved in regulating circadian rhythms?

Accepted Answer

Melatonin

Question 10

A patient with Type II diabetes mellitus is most likely to have which of the following conditions?

Accepted Answer

Normal insulin production but decreased tissue sensitivity to insulin (insulin resistance)

Question 11

Which of the following is a correct description of steroid hormones?

Accepted Answer

They are derived from cholesterol and bind to intracellular receptors.

Question 12

Which hormone is released by the posterior pituitary and is responsible for stimulating uterine contractions during labor?

Accepted Answer

Oxytocin (OXT)

Question 13

Which of the following best describes the effect of glucocorticoids (such as cortisol) on the immune system?

Accepted Answer

They inhibit activities of white blood cells and have anti-inflammatory effects.

Question 14

Which hormone is released in response to high blood glucose levels and what is its effect on target cells?

Accepted Answer

Insulin; accelerates glucose uptake and use

Question 15

Which of the following equations correctly represents the conversion of ATP to cyclic AMP by adenylate cyclase?

Accepted Answer

$$\mathrm{ATP} \xrightarrow{	ext{adenylate\ cyclase}} \mathrm{cAMP} + \mathrm{PP_i}$$

Question 16

Which hormone is secreted by the adrenal medulla and primarily binds to beta receptors, causing bronchodilation?

Accepted Answer

Epinephrine

Question 17

Which of the following best describes the role of thyroid hormones in children?

Accepted Answer

They are essential for normal development of skeletal, muscular, and nervous systems.

Question 18

Which of the following is a major effect of parathyroid hormone (PTH) on the kidneys?

Accepted Answer

It enhances reabsorption of calcium, reducing urinary losses.

Question 19

Which of the following best describes the effect of up-regulation of hormone receptors?

Accepted Answer

Cells become more sensitive to the hormone due to increased receptor numbers.

Question 20

A patient with untreated diabetes mellitus is at risk for which of the following complications?

Accepted Answer

Kidney degeneration, retinal damage, and peripheral tissue damage

The Endocrine System: Structure, Function, and Hormonal Regulation

Study Guide - Practice Questions