Question 1

Thyroxine
A)reduces the rate at which carbohydrates are utilized.
B)enhances the rate at which proteins are synthesized.
C)inhibits responses of the nervous system.
D)inhibits the rate at which calcium enters body fluids.

Accepted Answer

Thyroxine enhances the rate at which proteins are synthesized, thereby increasing metabolism and promoting growth and development. It does not reduce the rate at which carbohydrates are utilized, inhibit responses of the nervous system, or inhibit the rate at which calcium enters body fluids.

Question 2

Cortisol
A)increases the permeability of capillary walls.
B)increases the permeability of lysosomal membranes.
C)stimulates the production of glucose from noncarbohydrates.
D)promotes the storage of amino acids in the form of proteins.

Accepted Answer

Cortisol stimulates gluconeogenesis, which is the production of glucose from noncarbohydrate sources such as amino acids and fatty acids.

Answer: B
 This statement is incorrect. Cortisol does not increase the permeability of lysosomal membranes.

Answer: D
 This statement is incorrect. Cortisol promotes the breakdown of proteins to amino acids and the release of amino acids into the bloodstream, which can then be used as a source of glucose or energy.

Answer: A
 This statement is incorrect. Cortisol does not directly affect the permeability of capillary walls. However, it can indirectly increase capillary permeability by promoting inflammation and the release of inflammatory mediators.

Question 3

Kristin discovers a lump in her neck. Upon examination, her physician determines it's a tumor of the thyroid and performs a complete removal. Which of the following is not one of the hormones Kristin will need to be supplemented with?
A)Cholecalciferol
B)Triiodothyronine
C)Calcitonin
D)Thyroxine

Accepted Answer

Cholecalciferol is a form of vitamin D and is not a hormone produced by the thyroid gland. Therefore, Kristin will not need to be supplemented with cholecalciferol after the removal of her thyroid gland. However, she will need to be supplemented with triiodothyronine, thyroxine, and possibly calcitonin, which are hormones produced by the thyroid gland.

Question 4

In addition to a drop in blood calcium concentration, a symptom of hypoparathyroidism is
A)a rise in vitamin D concentration.
B)increased PTH secretion.
C)muscle cramps.
D)kidney stones.

Accepted Answer

Muscle cramps are a common symptom of hypoparathyroidism due to low levels of parathyroid hormone (PTH), which plays a role in calcium regulation and muscle function. A decrease in blood calcium concentration is also a symptom, not a rise in vitamin D concentration or increased PTH secretion. Kidney stones are more commonly associated with hyperparathyroidism, where there is an excess of PTH.

Question 5

Simple goiter is most prevalent where the soil lacks
A)organic matter.
B)vitamins.
C)iodine.
D)potassium.

Accepted Answer

Simple goiter is caused by the deficiency of iodine in the soil, which leads to a lack of iodine in the diet. Iodine is an essential element that is required for the synthesis of thyroid hormones. When the body does not get enough iodine, the thyroid gland enlarges to try and compensate for the deficiency, leading to the formation of a goiter.

Question 6

Hyposecretion of hormones from the adrenal cortex leads to
A)Cushing syndrome.
B)Addison disease.
C)buffalo hump.
D)moon face.

Accepted Answer

Hyposecretion of hormones from the adrenal cortex specifically leads to Addison disease, not Cushing syndrome, buffalo hump, or moon face.

Question 7

Infantile hypothyroidism results from
A)a deficiency of thyroid hormones at birth.
B)hyperthyroidism in an adult.
C)hypothyroidism in an adult.
D)lack of prolactin.

Accepted Answer

Infantile hypothyroidism results from a deficiency of thyroid hormones at birth. It can be caused by various factors, such as a congenital defect or an iodine deficiency during pregnancy.

Question 8

The secretion of parathyroid hormone is controlled primarily by the
A)hypothalamus.
B)concentration of blood calcium.
C)thyroid gland.
D)pituitary gland.

Accepted Answer

Parathyroid hormone secretion is primarily controlled by the concentration of calcium in the blood. When calcium levels are low, parathyroid hormone secretion increases to increase blood calcium levels. When calcium levels are high, parathyroid hormone secretion decreases to lower blood calcium levels. The hypothalamus and pituitary gland can indirectly affect parathyroid hormone secretion through their influence on the calcium-regulating hormones calcitonin and vitamin D, but they are not the primary controllers of parathyroid hormone secretion. The thyroid gland does not play a direct role in parathyroid hormone secretion.

Question 9

Graves disease, the most common form of hyperthyroidism, is caused by
A)a lack of iodine.
B)an excess of iodine.
C)an improper diet.
D)an autoimmune disorder.

Accepted Answer

Graves disease is an autoimmune disorder in which the immune system mistakenly attacks the thyroid gland, leading to an overproduction of thyroid hormones and resulting in hyperthyroidism.

Question 10

A hormone that the adrenal medulla secretes is
A)mineralocorticoid.
B)glucocorticoid.
C)aldosterone.
D)epinephrine.

Accepted Answer

The hormone that the adrenal medulla secretes is epinephrine, also known as adrenaline. Mineralocorticoids and aldosterone are secreted by the adrenal cortex, and glucocorticoids are also secreted by the adrenal cortex, not the medulla.

Question 11

________ inhibits secretion of prolactin.
A)Dopamine from the hypothalamus
B)Insulin
C)Norepinephrine
D)Growth hormone

Accepted Answer

Dopamine from the hypothalamus inhibits secretion of prolactin by the anterior pituitary gland.

Question 12

One of the hallmarks of Graves disease is
A)weight gain.
B)increased thirst.
C)decreased appetite.
D)goiter.

Accepted Answer

One of the hallmarks of Graves disease is goiter, which is an enlarged thyroid gland. It is caused by an overactive thyroid gland (hyperthyroidism) that produces too much thyroid hormone. This excessive hormone production can lead to symptoms such as weight loss, increased thirst, and increased appetite, but these are not hallmark symptoms of Graves disease.

Question 13

Cortisol is useful in controlling inflammation reactions because it
A)decreases the permeability of capillaries.
B)increases synthesis of prostaglandins.
C)destabilizes lysosomal membranes.
D)decreases blood flow.

Accepted Answer

Cortisol decreases the permeability of capillaries, which helps to reduce the amount of fluid and immune cells that can accumulate in the affected tissue during an inflammatory response. This can help to limit damage to the tissue and promote healing.

Question 14

Aldosterone promotes the homeostasis of ions by causing the kidneys to
A)conserve sodium and excrete potassium.
B)excrete sodium and conserve potassium.
C)excrete sodium and potassium.
D)conserve sodium and potassium.

Accepted Answer

Aldosterone promotes the reabsorption of sodium ions and the secretion of potassium ions in the distal tubules and collecting ducts of the kidneys, which leads to the conservation of sodium and excretion of potassium.

Question 15

Maxwell has a very high metabolic rate, is skinny, and has protruding eyes. These are symptoms of
A)hypothyroidism.
B)hyperthyroidism.
C)hypoparathyroidism.
D)hyperparathyroidism.

Accepted Answer

The symptoms described in the question (high metabolic rate, skinny, protruding eyes) suggest hyperthyroidism, which is an overactive thyroid gland. The thyroid gland produces hormones that regulate metabolism, and when it is overactive, it can lead to weight loss, fast heart rate, and other symptoms. Hypothyroidism, on the other hand, is an underactive thyroid gland and can lead to symptoms such as weight gain, fatigue, and slow heart rate. Hypoparathyroidism and hyperparathyroidism involve the parathyroid glands and can lead to abnormal calcium levels in the blood, but do not typically cause the symptoms described in the question.

Question 16

Hyperparathyroidism
A)is detected by low blood calcium ion concentration.
B)is most often caused by a tumor.
C)is most often caused by injury.
D)causes bulging eyes and goiters.

Accepted Answer

The answer of Hyperparathyroidism
A)is detected by low blood calcium ion...

Question 17

The hormone that stimulates calcium deposition into bone is
A)calcitonin.
B)parathyroid hormone.
C)thyroxine.
D)insulin.

Accepted Answer

Calcitonin is a hormone secreted by the thyroid gland that decreases the concentration of calcium in the blood by stimulating its deposition into bone. It also inhibits osteoclast activity, which helps to maintain bone density.

Question 18

The ________ secretes triiodothyronine.
A)adrenal gland
B)pancreas
C)parathyroid gland
D)thyroid gland

Accepted Answer

The thyroid gland is responsible for secreting triiodothyronine, along with other thyroid hormones such as thyroxine. The adrenal gland secretes hormones such as adrenaline and cortisol, the pancreas secretes insulin and glucagon, and the parathyroid gland is responsible for regulating calcium levels in the body.

Question 19

The opposing roles of the thyroid and parathyroid maintain the balance of calcium and phosphate ions in the blood. What will happen if the parathyroid gland develops a defect that prevents PTH secretion?
A)The amount of calcium ions and phosphate ions in the blood will increase.
B)The amount of calcium ions in the blood will increase and the amount of phosphate ions will decrease.
C)The amount of calcium ions in the blood will decrease and the amount of phosphate ions will increase.
D)The amount of calcium ions and phosphate ions in the blood will decrease.

Accepted Answer

The answer of The opposing roles of the thyroid and...

Question 20

Which of the following statements is correct with respect to T₃ and T₄?
A)T₄ has a higher free concentration in the plasma.
B)T₄ is more important physiologically.
C)About one-third of T₄ is converted to T₃ in peripheral tissues.
D)T₄ is more potent.

Accepted Answer

About one-third of T₄ is converted to T₃ in peripheral tissues. Both T₃ and T₄ are important hormones produced by the thyroid gland, but T₄ is considered a prohormone because it is converted to the more biologically active T₃ in peripheral tissues. T₄ has a longer half-life than T₃ and a higher total concentration in the plasma, but T₃ has a higher free concentration and is more potent physiologically.

Quiz 13: Endocrine System

Thyroxine

Cortisol

Kristin discovers a lump in her neck. Upon examination, her physician determines it's a tumor of the thyroid and performs a complete removal. Which of the following is not one of the hormones Kristin will need to be supplemented with?

In addition to a drop in blood calcium concentration, a symptom of hypoparathyroidism is

Simple goiter is most prevalent where the soil lacks

Hyposecretion of hormones from the adrenal cortex leads to

Infantile hypothyroidism results from

The secretion of parathyroid hormone is controlled primarily by the

Graves disease, the most common form of hyperthyroidism, is caused by

A hormone that the adrenal medulla secretes is

________ inhibits secretion of prolactin.

One of the hallmarks of Graves disease is

Cortisol is useful in controlling inflammation reactions because it

Aldosterone promotes the homeostasis of ions by causing the kidneys to

Maxwell has a very high metabolic rate, is skinny, and has protruding eyes. These are symptoms of

Hyperparathyroidism

The hormone that stimulates calcium deposition into bone is

The ________ secretes triiodothyronine.

The opposing roles of the thyroid and parathyroid maintain the balance of calcium and phosphate ions in the blood. What will happen if the parathyroid gland develops a defect that prevents PTH secretion?

Which of the following statements is correct with respect to T₃ and T₄?