Question 1

Which of the following best describes the anatomical location and histological organization of the thyroid gland?

Accepted Answer

It is located anterior to the trachea and consists of follicles filled with colloid.

Question 2

Which hormone is most biologically active among the two major thyroid hormones, and which is produced in greatest abundance?

Accepted Answer

Triiodothyronine (T3) is most active; Thyroxine (T4) is produced in greatest abundance.

Question 3

A patient presents with symptoms of hyperthyroidism. Which of the following is a likely effect of excess thyroid hormone?

Accepted Answer

Increased basal metabolic rate and heat intolerance.

Question 4

Which dietary factor is essential for thyroid hormone synthesis, and what is its role?

Accepted Answer

Iodine; it is incorporated into the structure of thyroid hormones.

Question 5

Which hormone is produced by the parathyroid gland, and what is its primary function?

Accepted Answer

Parathyroid hormone (PTH); it increases blood calcium levels by stimulating bone resorption.

Question 6

How is parathyroid hormone (PTH) regulated, and what type of control mechanism is involved?

Accepted Answer

By negative feedback in response to blood calcium levels.

Question 7

Which of the following correctly matches the major anatomical parts of the adrenal gland and their hormone secretions?

Accepted Answer

Cortex: corticosteroids; Medulla: catecholamines.

Question 8

A patient with Addison's disease has hyposecretion of adrenal cortex hormones. Which layer of the adrenal cortex is primarily affected, and which hormone is deficient?

Accepted Answer

Zona fasciculata; cortisol.

Question 9

Which hormone is released by the pineal gland, and what is its primary function?

Accepted Answer

Melatonin; regulation of circadian rhythms.

Question 10

Which pancreatic cells are endocrine, and what are the two major hormones they produce?

Accepted Answer

Islets of Langerhans; insulin and glucagon.

Question 11

A patient with diabetes mellitus has high blood glucose levels. Which hormone is deficient, and what is its normal function?

Accepted Answer

Insulin; promotes glucose uptake by cells.

Question 12

Which hormone is tested for in the urine during a home pregnancy test, and which organ produces it?

Accepted Answer

Human chorionic gonadotropin (hCG); placenta.

Question 13

Which of the following is a correct example of autocrine signaling?

Accepted Answer

A cell releases a hormone that binds to receptors on its own surface.

Question 14

Which of the following best describes the cAMP second messenger pathway?

Accepted Answer

A hormone binds to a receptor, activating adenylate cyclase, which converts ATP to cAMP, leading to protein kinase activation.

Question 15

Which equation correctly represents the conversion of ATP to cAMP in the second messenger pathway?

Accepted Answer

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

Question 16

Which of the following is NOT a function of the hypothalamic-hypophyseal portal system?

Accepted Answer

Delivering hormones to the posterior pituitary for storage.

Question 17

Which hormone is produced by the zona glomerulosa of the adrenal cortex, and what is its main effect?

Accepted Answer

Aldosterone; increases sodium reabsorption in the kidneys.

Question 18

Which of the following correctly describes the difference between diabetes mellitus and diabetes insipidus?

Accepted Answer

Diabetes mellitus is due to insulin deficiency; diabetes insipidus is due to antidiuretic hormone (ADH) deficiency.

Question 19

Which of the following hormones is produced by the neurohypophysis (posterior pituitary), and what is its effect?

Accepted Answer

Oxytocin; stimulates uterine contractions and milk ejection.

Endocrine System: Major Glands, Hormones, and Mechanisms (Study Guide)

Study Guide - Practice Questions

Study Guide - Flashcards