$$\text{MIT} + \text{DIT} \rightarrow \text{T}_3$$

Question 1

Which of the following best describes the role of the thyroid hormone (TH) in the body?

Accepted Answer

It increases basal metabolic rate and heat production, affecting nearly every cell in the body.

Question 2

A patient presents with an enlarged thyroid gland (goiter) and symptoms of myxedema. Which of the following is the most likely cause?

Accepted Answer

Iodine deficiency resulting in decreased TH levels and increased TSH stimulation.

Question 3

Which hormone is secreted by the parafollicular cells of the thyroid gland and what is its primary function at high doses?

Accepted Answer

Calcitonin; inhibits osteoclast activity and promotes Ca$$^{2+}$$ uptake into bone matrix.

Question 4

Which of the following steps occurs FIRST in the synthesis of thyroid hormone?

Accepted Answer

Thyroglobulin is synthesized and discharged into the follicle lumen.

Question 5

A patient with Graves’ disease is likely to exhibit which of the following symptoms?

Accepted Answer

Elevated metabolic rate, rapid and irregular heartbeats, and exophthalmos.

Question 6

Which of the following equations correctly represents the formation of triiodothyronine (T$$_3) $$from iodinated tyrosines?

Accepted Answer

$$	ext{MIT} + 	ext{DIT} ightarrow 	ext{T}_3$$

Question 7

Which hormone is most important for Ca$$^{2+}$$ homeostasis and what is its effect on the kidneys?

Accepted Answer

Parathyroid hormone (PTH); enhances reabsorption of Ca$$^{2+}$$ and secretion of phosphate.

Question 8

A patient with hypoparathyroidism following gland removal is at risk for which of the following complications?

Accepted Answer

Tetany, respiratory paralysis, and death.

Question 9

Which layer of the adrenal cortex is responsible for producing mineralocorticoids, and what is the primary mineralocorticoid?

Accepted Answer

Zona glomerulosa; aldosterone.

Question 10

Which mechanism is primarily responsible for stimulating aldosterone release in response to decreased blood pressure?

Accepted Answer

Renin-angiotensin-aldosterone mechanism.

Question 11

Which of the following is a primary metabolic effect of cortisol?

Accepted Answer

Promotes gluconeogenesis, forming glucose from fats and proteins.

Question 12

A patient with Cushing’s syndrome is likely to exhibit which of the following signs?

Accepted Answer

Moon face and buffalo hump due to fat redistribution.

Question 13

Which hormone is secreted by the adrenal medulla and is primarily responsible for stimulating metabolic activities such as bronchial dilation?

Accepted Answer

Epinephrine.

Question 14

Which of the following best describes the effect of insulin on blood glucose levels?

Accepted Answer

Insulin lowers blood glucose by enhancing membrane transport of glucose into fat and muscle cells.

Question 15

A patient with untreated diabetes mellitus is likely to experience which of the following metabolic consequences?

Accepted Answer

Lipidemia and ketoacidosis due to increased fat metabolism.

Question 16

Which hormone is secreted by the heart and functions to decrease blood pressure by reducing blood Na$$^+$$ concentration?

Accepted Answer

Atrial natriuretic peptide (ANP).

Question 17

Which hormone produced by adipose tissue acts as an insulin antagonist?

Accepted Answer

Resistin.

Question 18

Which hormone is secreted by the kidneys and signals the production of red blood cells?

Accepted Answer

Erythropoietin.

Question 19

Which hormone is secreted by the pineal gland and is involved in regulating day/night cycles?

Accepted Answer

Melatonin.

Question 20

Which hormone is produced by the skeleton and helps improve glucose handling and reduce body fat?

Accepted Answer

Osteocalcin.

The Endocrine System: Thyroid, Parathyroid, Adrenal, Pineal, Pancreas, and Other Endocrine Organs

Study Guide - Practice Questions