Thyroid Gland: Structure, Function, and Regulation - Physiology Quiz

Question 1

Which of the following amino acids is incorporated into thyroid hormones during their synthesis?

Accepted Answer

Glycine and serine

Answer

Alanine and isoleucine

Answer

Phenylalanine and tyrosine

Answer

Methionine and cysteine

Question 2

What enzyme catalyzes the iodination of thyroglobulin, the precursor protein for thyroid hormones, in the thyroid gland?

Accepted Answer

Thyroid peroxidase

Answer

Thyroglobulin synthetase

Answer

Thyroid hormone hydroxylase

Answer

Deiodinase

Question 3

What is the most prevalent cause of hypothyroidism in the United Kingdom?

Accepted Answer

Hashimoto's thyroiditis

Answer

Iodine deficiency

Answer

Graves' disease

Answer

Hyperparathyroidism

Question 4

Which cells in the thyroid gland synthesize and secrete thyroid hormones?

Accepted Answer

Follicular cells

Answer

Parafollicular cells

Answer

C cells

Answer

Thyroid-stimulating hormone (TSH) cells

Question 5

Describe the sequential steps involved in thyroid hormone synthesis.

Accepted Answer

Iodide uptake -> Thyroglobulin iodination -> Thyroglobulin coupling -> T3 and T4 formation

Answer

Thyroglobulin coupling -> Iodide uptake -> Thyroglobulin iodination -> T3 and T4 formation

Answer

Thyroglobulin iodination -> Thyroglobulin coupling -> Iodide uptake -> T3 and T4 formation

Answer

T3 and T4 formation -> Thyroglobulin coupling -> Iodide uptake -> Thyroglobulin iodination

Question 6

Identify a clinical manifestation of hyperthyroidism.

Accepted Answer

Tachycardia

Answer

Weight gain

Answer

Constipation

Answer

Myxedema

Question 7

What is the standard first-line treatment for hypothyroidism?

Accepted Answer

Thyroid hormone replacement therapy

Answer

Radioactive iodine ablation

Answer

Surgery

Answer

Beta-blockers

Question 8

What radioactive isotope of iodine is used in thyroid function tests and treatment?

Accepted Answer

Iodine-131

Answer

Iodine-123

Answer

Iodine-125

Answer

Iodine-141

Question 9

What is the most common cause of secondary hypothyroidism?

Accepted Answer

Pituitary disease

Answer

Hypothalamic disease

Answer

Thyroid disease

Answer

Iodine deficiency

Question 10

Which of the following is a typical symptom of hypothyroidism, but NOT hyperthyroidism?

Accepted Answer

Constipation

Answer

Weight loss

Answer

Heat intolerance

Answer

Tremor

Question 11

Which of the following is NOT involved in the synthesis of thyroid hormones?

Accepted Answer

Serotonin

Answer

Tyrosine

Answer

Iodine

Answer

Thyroglobulin

Question 12

What is the primary role of thyroxine-binding globulin (TBG)?

Accepted Answer

To facilitate the transport of thyroid hormones to various tissues

Answer

To control the release of thyroid hormones from the thyroid gland

Answer

To convert thyroxine (T4) to triiodothyronine (T3)

Answer

To bind to thyroid hormone receptors and initiate cellular responses

Question 13

Which of the following hormones stimulates the release of thyroid hormones from the thyroid gland?

Accepted Answer

Thyroid-stimulating hormone (TSH)

Answer

Prolactin

Answer

Luteinizing hormone (LH)

Answer

Follicle-stimulating hormone (FSH)

Question 14

What is the name of the condition characterized by excessive thyroid hormone production?

Accepted Answer

Hyperthyroidism

Answer

Hypothyroidism

Answer

Thyroiditis

Answer

Grave's disease

Question 15

Which protein is responsible for binding to thyroid hormone receptors and initiating gene transcription?

Accepted Answer

Thyroid hormone receptor

Answer

Thyroglobulin

Answer

Thyroid peroxidase

Answer

Thyroid hormone-binding globulin

Question 16

Which of the following is NOT a physiological effect of thyroid hormones?

Accepted Answer

Decreased oxygen consumption

Answer

Increased metabolic rate

Answer

Enhanced bone growth

Answer

Stimulation of linear growth

Question 17

Which of the following is a potential side effect of using radioactive iodine therapy for thyroid cancer?

Accepted Answer

Hypothyroidism

Answer

Hyperthyroidism

Answer

Arrhythmias

Answer

Pneumonia

Question 18

Which gland produces parathyroid hormone (PTH)?

Accepted Answer

Parathyroid glands

Answer

Pituitary gland

Answer

Adrenal glands

Answer

Hypothalamus

Question 19

Which step is NOT involved in the synthesis of thyroid hormones?

Accepted Answer

Deiodination

Answer

Coupling of iodotyrosines

Answer

Iodide uptake

Answer

Thyroglobulin iodination

Question 20

The secretion of thyroid hormones is primarily regulated by which pituitary hormone?

Accepted Answer

Thyrotropin (TSH)

Answer

Growth hormone (GH)

Answer

Adrenocorticotropic hormone (ACTH)

Question 21

The primary physiological role of thyroid hormones is to:

Accepted Answer

Increase metabolic rate

Answer

Control fluid balance

Answer

Regulate blood glucose levels

Answer

Stimulate bone growth

Question 22

Anatomically, the thyroid gland is located in the:

Accepted Answer

Anterior neck

Answer

Mediastinum

Answer

Posterior neck

Question 23

The iodine required for thyroid hormone synthesis is primarily obtained from:

Accepted Answer

Iodized salt

Answer

Meat

Answer

Fruits

Answer

Dairy products

Question 24

The thyroid gland originates from which embryonic structure?

Accepted Answer

Pharyngeal pouches

Answer

Neural tube

Answer

Mesoderm

Answer

Notochord