Which of the following statements is NOT true of the endocrine system?

a. It is one of two major regulatory systems of the body.

b. It is composed of glands that secrete chemical messengers into the blood.

c. It is an important regulator of homeostatic mechanisms.

d. It influences and is influenced by the nervous system.

e. Most of its components are anatomically connected, like most other systems of the body.

e. Most of its components are anatomically connected, like most other systems of the body.

Which does NOT apply to hormones?

a. They are chemical regulators that are conveyed from one organ to another via the bloodstream.

b. In some cases, the same chemical substances can also function as local regulators and/or neurotransmitters.

c. All hormones are derived from cholesterol.

d. They are secreted into the blood by ductless glands.

e. They are sometimes secreted by neural tissue.

c. All hormones are derived from cholesterol.

What is the definition of a prohormone?

a. Hormones that bind to endocrine glands and stimulate the secretion of a second hormone

b. Hormones that bind to endocrine glands and inhibit the secretion of a second hormone

c. A longer protein or peptide that is cleaved into shorter ones, at least one of which is a peptide or protein hormone

d. Hormones that stimulate the expression of receptors for a second hormone, promoting their action

e. Steroid hormones that are inactivated by having hydroxyl groups removed from their structure

c. A longer protein or peptide that is cleaved into shorter ones, at least one of which is a peptide or protein hormone

A hormone may be

a. inactivated by its target cell.

b. activated by its target cell.

c. inactivated by nontarget cells.

d. excreted before it has a chance to act on a target cell.

e. All of the choices could be correct.

e. All of the choices could be correct.

How is the concentration of a hormone in plasma determined?

a. Only by its rate of secretion

b. By the number of its target cells in the body

c. Only by its rate of synthesis

d. By its secretion and clearance rates, and whether or not it binds to carriers and/or other plasma proteins

e. Only by the rate of its degradation by the liver and kidneys

d. By its secretion and clearance rates, and whether or not it binds to carriers and/or other plasma proteins

What is a main difference between the modes of action of peptide hormones and steroid hormones?

a. Peptide hormones bind to intracellular receptors, whereas steroid hormones bind to receptors on the cell surface.

b. Peptide hormones act as second messengers, whereas steroid hormones bind to receptors in the cytosol.

c. Peptide hormones bind to receptors on the cell surface, whereas steroid hormones act as second messengers.

d. Peptide hormones bind to receptors on the cell surface, whereas steroid hormones bind to intracellular receptors.

e. There are no differences; both act by binding to intracellular receptors.

d. Peptide hormones bind to receptors on the cell surface, whereas steroid hormones bind to intracellular receptors.

Acting alone, epinephrine and thyroid hormone each stimulates release of only a small amount of fatty acids from adipose cells. In the presence of thyroid hormone, epinephrine causes a much more substantial release of fatty acids from the cells. What is the term describing the effect of thyroid hormone on epinephrine's actions?

a. Antagonistic

b. Agonistic

c. Permissive

d. Direct

e. Paracrin

c. Permissive

What term describes hormones that influence the secretion of other hormones?

a. Mineralocorticoids

b. Antagonistic

c. Tropic

d. Allosteric

e. Teratogen

c. Tropic

Which of the following hormones is NOT secreted by the anterior pituitary gland?

a. Somatotropin

b. Prolactin

c. Corticotropin

d. Erythropoietin

e. Thyroid-stimulating hormone (TSH)

d. Erythropoietin

What term describes hormones secreted by the hypothalamus that regulate the secretion of hormones from the anterior pituitary gland?

a. Growth factorsc. Hypophysiotropic hormones

b. Paracrine factors

d. Metabotrobic-releasing factors

e. Cerebrovitalistic hormones

c. Hypophysiotropic hormones

A chemical precursor for cortisol is __________, which is made from __________. Cortisol is secreted by __________ when stimulated by __________ from the anterior pituitary.

a. androstenedione; progesterone; adrenal cortex; corticotropin-releasing hormone (CRH)

b. progesterone; cholesterol; adrenal medulla; adrenocorticotropic hormone (ACTH)

c. testosterone; cholesterol; adrenal medulla; adrenocorticotropic hormone (ACTH)

d. progesterone; cholesterol; adrenal cortex; adrenocorticotropic hormone (ACTH)

e. estradiol; cholesterol; adrenal medulla; corticotropin-releasing hormone (CRH)

d. progesterone; cholesterol; adrenal cortex; adrenocorticotropic hormone (ACTH)

Which is an accurate description of the posterior pituitary and its functions?

a. It is glandular tissue and secretes vasopressin and prolactin.

b. It is neural tissue and is stimulated to secrete oxytocin and vasopressin by hypophysiotropic hormones.

c. It is neural tissue, and vesicles containing oxytocin and vasopressin are transported to axon terminals there.

d. It is glandular tissue and releases oxytocin and somatostatin when action potentials arrive along axons from the hypothalamus.

e. It is neural tissue that secretes hypophysiotropic hormones that control the secretion of the anterior pituitary hormones.

c. It is neural tissue, and vesicles containing oxytocin and vasopressin are transported to axon terminals there.

Which is a function of the gonadotropic hormones?

a. Stimulating the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

b. Inhibiting the release of growth hormone

c. Inhibiting the release of prolactin

d. Inducing the secretion of steroid hormones by the gonads in both males and females

e. Stimulating the release of gonadotropin-releasing hormone (GnRH)

d. Inducing the secretion of steroid hormones by the gonads in both males and females

Short-loop negative feedback occurs when hormones from the __________ inhibit hormone secretion by the __________.

a. hypothalamus; anterior pituitary

b. adrenal cortex; hypothalamus

c. anterior pituitary; hypothalamus

d. adrenal cortex; anterior pituitary

e. anterior pituitary; adrenal cortex

c. anterior pituitary; hypothalamus

To synthesize thyroid hormones, iodine is attached to

a. cholesterol.

b. the amino acid tyrosine.

c. the amino acid tryptophan.

d. acetyl coenzyme A.

e. the amino acid phenylalanine.

b. the amino acid tyrosine.

Which is a result of an absence of thyroid hormones during fetal development?

a. Acromegaly

b. Cushing's syndrome

c. Congenital hypothyroidism (cretinism)

d. Graves' disease

e. Addison's disease

c. Congenital hypothyroidism (cretinism)

Which is an example of long-loop negative feedback?

a. Stimulation of dopamine release by prolactin

b. Inhibition of growth hormone-releasing hormone (GHRH) release by growth hormone (GH)

c. Inhibition of growth hormone-releasing hormone (GHRH) release by insulin-like growth factor-1

d. Inhibition of corticotropin-releasing hormone by adrenocorticotropic hormone (ACTH)

e. Stimulation of thyroid-stimulating hormone (TSH) release by thyrotropin-releasing hormone (TRH)

c. Inhibition of growth hormone-releasing hormone (GHRH) release by insulin-like growth factor-1

A deficiency in dietary iodine can cause

a. congenital hypothyroidism (cretinism).

b. a slowing of mental functions.

c. a low metabolic rate.

d. a goiter.

e. All of the choices are correct.

e. All of the choices are correct.

Deficiency of iodine in the diet results in __________ caused by __________.

a. a goiter; increased production of thyroid-stimulating hormone (TSH) and increased thyroid hormone levels

b. atrophy of the thyroid gland; loss of negative feedback by thyroid hormones and increased thyroid-stimulating hormone (TSH) levels

c. a goiter; loss of negative feedback by thyroid hormones and increased thyroid-stimulating hormone (TSH) levels

d. atrophy of the thyroid gland; decreased sensitivity of receptors for thyroid-stimulating hormone (TSH)

e. atrophy of the anterior pituitary gland; loss of negative feedback by thyroid hormones

c. a goiter; loss of negative feedback by thyroid hormones and increased thyroid-stimulating hormone (TSH) levels

What is the major hormone responsible for mediating the body's general response to stress?

a. Thyroid hormone

b. Growth hormone

c. Testosterone

d. Aldosterone

e. Cortisol

e. Cortisol

Which of the following is NOT stimulated by cortisol during stress?

a. Gluconeogenesis

b. Protein catabolism

c. Glucose uptake into muscle cells

d. Triglyceride catabolism in adipose cells

e. Decreased sensitivity to insulin

c. Glucose uptake into muscle cells

Which statement best describes the manner in which growth hormone stimulates cell proliferation?

a. It directly stimulates cell division in most tissues.

b. It stimulates the release of insulin-like growth factor I (IGF-1) from the liver and other target tissues of growth hormone.

c. It stimulates metabolism.

d. It stimulates the release of eicosanoids from lymphoid tissues.

e. It stimulates sleep.

b. It stimulates the release of insulin-like growth factor I (IGF-1) from the liver and other target tissues of growth hormone.

Which is NOT an effect of parathyroid hormone?

a. Increases the bone-degrading activity of osteoclasts

b. Decreases reabsorption of calcium by the kidneys

c. Promotes vitamin D synthesis, leading to increased intestinal absorption of calcium

d. Increases plasma [Ca²⁺]

e. Decreases reabsorption of phosphate by the kidneys

b. Decreases reabsorption of calcium by the kidneys

If the adrenal glands were removed from a patient, his plasma cortisol levels would __________, secretion of CRH by the __________ would __________, and secretion of ACTH by the __________ would __________.

a. increase; hypothalamus; decrease; anterior pituitary gland; decrease

b. decrease; hypothalamus; increase; adenohypophysis; increase

c. decrease; anterior pituitary gland; increase; hypothalamus; increase

d. increase; hypothalamus; increase; adenohypophysis; increase

e. decrease; adenohypophysis; increase; anterior pituitary gland; increase

b. decrease; hypothalamus; increase; adenohypophysis; increase

Sally is a 10-year-old girl going through a growth spurt. Her blood levels of growth hormone are two-fold higher than at the same time last week. Which other hormones are likely to also be elevated?

a. Insulin-like growth factor 1

b. Prolactin

c. Cortisol

d. ACTH

e. Follicle-stimulating hormone

a. Insulin-like growth factor 1