Deck 17: Endocrine System

Question 1

The hormones and neurotransmitters released by the endocrine and nervous systems are chemical substances referred to as ________.

Answer 1

ligands

Question 2

Compared to the nervous system, the endocrine system has

A) more localized and long-lasting effects.
B) more widespread and long-lasting effects.
C) more localized and short-term effects.
D) more widespread and short-term effects.

Answer 2

B

Question 3

Thyroid hormone is somewhat unique in that it is a

A) biogenic amine that is lipid-soluble.
B) protein hormone that is water-soluble.
C) steroid hormone that is water-soluble.
D) steroid hormone that is lipid-soluble.
E) monoamine that is water-soluble.

Answer 3

A

Question 4

Follicle-stimulating hormone is a

A) glycoprotein.
B) steroid.
C) monoamine.
D) oligopeptide.

Question 5

The liver contains endocrine cells.

Question 6

The small, cone-shaped gland that is in the epithalamus of the brain is the ________ gland.

Question 7

Eicosanoids are a primary type of local hormone.

Question 8

Protein hormones are

A) lipid-soluble.
B) water-soluble.
C) soluble in both water and lipids.
D) soluble in neither water nor lipids.

Question 9

The reaction time for endocrine effects is generally measured in milliseconds.

Question 10

Modified amino acids that act as hormones are referred to as ________ amines.

Question 11

Aldosterone release can be triggered by the presence of the blood-borne messenger angiotensin II or by low levels of sodium, and so its secretion regulation is said to be

A) purely neural.
B) both hormonal and humoral.
C) both antagonistic and synergistic.
D) both neural and synergistic.
E) purely hormonal.

Question 12

Endocrine glands

A) are ductless glands.
B) are the organs of the endocrine system.
C) secrete hormones directly into the bloodstream.
D) help maintain homeostasis.
E) All of the choices are correct.

Question 13

Parathyroid hormone release depends on blood levels of calcium. Such an endocrine reflex is said to be initiated by

A) hormonal stimulation.
B) humoral stimulation.
C) neural stimulation.
D) positive feedback stimulation.

Question 14

Eicosanoids are synthesized from

A) cholesterol.
B) prostaglandin.
C) arachidonic acid.
D) amino acids.

Question 15

Among their many functions, hormones regulate blood volume, cellular concentration, and number of platelets.

Question 16

The parathyroid glands are located

A) just below the thalamus.
B) within the thymus.
C) above the kidneys.
D) anterior to the thyroid gland.
E) posterior to the thyroid gland.

Question 17

Although hormones influence activity in the neural and reproductive systems, they do not influence the digestive system.

Question 18

Steroids, peptides, and nucleic acids are the three classes of hormones.

Question 19

Like proteins, eicosanoids are synthesized on ribosomes in a process that involves transcription and translation.

Question 20

Which is not characteristic of the endocrine system?

A) Effects: causes metabolic activity changes in target cells
B) Response time: slow reaction time = seconds to hours
C) Duration of response: long-lasting = minutes to weeks
D) Recovery time: rapid, immediate return to prestimulation level
E) Communication method: hormones in the bloodstream

Question 21

When eicosanoids bring about cellular changes within the cell from which they were formed, the process is called ________ stimulation.

Question 22

Steroid hormones are lipids, derived from

A) cholesterol.
B) glycerol.
C) amines.
D) polypeptides.
E) nucleic acids.

Question 23

Most hormones are made of chains of amino acids and are therefore

A) steroids.
B) biogenic amines.
C) proteins.
D) catecholamines.

Question 24

A G protein is

A) a type of water-soluble hormone.
B) a second messenger activated by a steroid hormone.
C) a molecule that binds a guanine nucleotide and helps transduce a signal inside a target cell.
D) a receptor for a water-soluble hormone that causes arachidonic acid to be extracted from a phospholipid.
E) an enzyme that catalyzes the conversion of ATP into cyclic AMP.

Question 25

The half-life of a hormone is

A) one-half of the time it takes to synthesize the chemical messenger molecule.
B) the time necessary to reduce the hormone concentration in the blood to half of what had been secreted.
C) half the time until the hormone molecule dissolves.
D) half of the duration of the hormone's effects on its target cells throughout the body.

Question 26

Within the adenylate cyclase signal transduction pathways of target cells, cAMP activates

A) the G protein.
B) adenylate cyclase.
C) protein kinase.
D) the receptor.
E) transcription of a mRNA.

Question 27

Oxytocin results in more forceful smooth muscle contractions in the uterus by causing target cells to increase production of

A) adenylate cyclase.
B) mRNA for myosin.
C) inositol triphosphate.
D) glucose.

Question 28

When a chemical messenger helps initiate an inflammatory response by causing cellular changes in neighboring cells, it is demonstrating ________ signaling.

A) autocrine
B) paracrine
C) allomone
D) pheromone

Question 29

Damage to the liver might impair enzymatic degradation of some hormones. The levels of such hormones in the blood would therefore be expected to

A) increase.
B) decrease.
C) remain unchanged.

Question 30

Intracellular signaling pathways within target cells are organized such that

A) each step allows for amplification of the signal where one molecule can activate many.
B) each step involves one molecule activating or synthesizing exactly one other molecule for precise control.
C) enzymes are used up and degraded after each individual reaction they catalyze.

Question 31

Lipid-soluble hormones, such as progesterone, exert their effects by forming hormone-receptor complexes that

A) activate a G protein and second-messenger cascade.
B) bind to DNA and initiate transcription.
C) open ion channels in the cell membrane.
D) activate adenylate cyclase.

Question 32

The binding of a hormone and a carrier protein is ________; a very ________ fraction of such a hormone in the blood is bound to a carrier at any one point in time.

A) temporary; large
B) temporary; small
C) permanent; large
D) permanent; small

Question 33

In the signal transduction pathway that results in the formation of inositol triphosphate, the G protein directly activates

A) phospholipase C.
B) protein kinase A.
C) calmodulin.
D) adenylate cyclase.

Question 34

Like all other hormone transport proteins, albumin is highly specific in terms of which hormone it carries through the blood.

Question 35

Which type of hormone requires a carrier protein in the blood?

A) Autocrine hormone
B) Water-soluble hormone
C) Oligopeptide
D) Lipid-soluble hormone

Question 36

Generally, there are two main factors that determine the levels of a hormone in the blood. Explain what those factors are and provide examples of how they might increase or decrease a hormone's level.

Question 37

Lipophilic hormones bind to ________ receptors of target cells.

A) intracellular
B) membrane-bound

Question 38

When the effects of water-soluble hormones on their target cells are considered, the hormone itself is

A) the G protein.
B) the second messenger.
C) the first messenger.
D) the hormone-response element.
E) the phospholipase.

Question 39

The word "cascade" can be defined as a series of small waterfalls, one leading to the next. Describe a specific second-messenger cascade that results from the series of chemical reactions (from one to the next) initiated by a hormone binding to its receptor.

Question 40

Generally, the shorter the half-life of a hormone

A) the more frequently it must be replaced.
B) the less frequently it must be replaced.

Question 41

The function of each of the regulatory hormones of the hypothalamus is to trigger the release of a tropic hormone from the pituitary.

Question 42

Within the infundibulum, the axons from neurons extending into the posterior pituitary are known as the

A) hypothalamo-hypophyseal tract.
B) primary plexus.
C) secondary plexus.
D) supraoptic portal system.

Question 43

Thyrotropin-releasing hormone is secreted by the

A) hypothalamus and it increases release of thyroid-stimulating hormone from the anterior pituitary.
B) hypothalamus and it increases release of thyroid-stimulating hormone from the posterior pituitary.
C) anterior pituitary and it increases release of thyroid hormone from the thyroid gland.
D) parathyroid hormone and it increases release of thyroid hormone from the thyroid gland.
E) thymus and it increases release of thyroid hormone from the thyroid gland.

Question 44

When the effects of one hormone reinforce the activity of another hormone on the same target cell, the interaction is said to be

A) agonistic.
B) antagonistic.
C) synergistic.
D) permissive.

Question 45

Glucagon and insulin work ________ on blood glucose levels.

A) antagonistically
B) permissively
C) synergistically

Question 46

Which lobe of the pituitary is larger and secretes more hormones?

A) Anterior pituitary
B) Posterior pituitary

Question 47

Reduced hormone concentration in the blood often causes target cells to

A) up-regulate receptors in order to increase cell sensitivity.
B) up-regulate receptors in order to decrease cell sensitivity.
C) down-regulate receptors in order to increase cell sensitivity.
D) down-regulate receptors in order to decrease cell sensitivity.

Question 48

The hormone oxytocin is synthesized in the

A) anterior pituitary.
B) posterior pituitary.
C) paraventricular nucleus.
D) pineal gland.
E) nucleus of the solitary tract.

Question 49

The term down-regulation refers to the process by which

A) a glandular cell decreases the amount of hormone it secretes.
B) a large amount of hormone shuts down all metabolic activity in a target cell.
C) a cell decreases the number of receptors it has for a hormone.
D) a carrier protein increases the rate of degradation for a hormone and thereby decreases its blood concentration.
E) a carrier protein decreases the rate of degradation of the protein it ferries.

Question 50

The pituitary gland is located ________ to the hypothalamus and is connected by the ________.

A) superior; thalamus
B) inferior; infundibulum
C) inferior; epithalamus
D) posterior; infundibulum

Question 51

As someone starts to develop in puberty, most cells in their reproductive organs are probably starting to express

A) more receptors for sex hormones.
B) fewer receptors for sex hormones.

Question 52

Once a structure is fully grown and mature, it will probably

A) up-regulate its receptors for growth hormone, as it no longer receives as much of the ligand.
B) up-regulate its receptors for growth hormone, as it no longer needs to continue to grow at a fast rate.
C) down-regulate its receptors for growth hormone, as it no longer receives as much of the ligand.
D) down-regulate its receptors for growth hormone, as it no longer needs to continue to grow at a fast rate.

Question 53

The two hormones released from the posterior pituitary are

A) oxytocin and antidiuretic hormone.
B) thyrotropin-releasing hormone and corticotropin-releasing hormone.
C) prolactin and growth hormone.
D) prolactin and vasopressin.
E) follicle-stimulating hormone and luteinizing hormone.

Question 54

Where is the pituitary gland located?

A) Within the sella turcica of the sphenoid bone
B) Between the cerebrum and cerebellum, inferior to the occipital lobe
C) On the posterior surface of the thyroid gland
D) On the tracheal surface, inferior to the larynx
E) Within the third ventricle of the brain

Question 55

In which order would blood flow through these structures as it travels from the hypothalamus to the pituitary gland?
A: Primary plexus
B: Secondary plexus
C: Hypophyseal portal veins

A) a - b - c
B) a - c - b
C) c - a - b
D) b - a - c
E) c - b - a

Question 56

The anterior pituitary is also called the adenohypophysis.

Question 57

The part of the brain that functions as a "master control center" of the endocrine system is the

A) pineal gland.
B) cerebral cortex.
C) spinal cord.
D) hypothalamus.
E) adrenal cortex.

Question 58

When the activity of one hormone requires that of a second hormone, the interaction is said to be ________.

Question 59

The hormones that come from the posterior pituitary

A) are synthesized there and are released upon signals from the anterior pituitary.
B) are synthesized in the hypothalamus and are released from the posterior pituitary when nerve signals arrive.
C) are synthesized in the anterior pituitary and are transported to and from the posterior pituitary by the primary and secondary plexus.
D) are synthesized in the posterior pituitary and released by the anterior pituitary by way of the hypophyseal portal system.

Question 60

The hypothalamic hormone that triggers the release of adrenocorticotropic hormone (ACTH) is

A) cortisol.
B) corticotropin-releasing hormone (CRH).
C) vasopressin.
D) adrenal follicle-stimulating hormone.
E) cortical stimulating factor (CSF).

Question 61

The release of hormones from the adrenal cortex is stimulated by

A) thyroid hormone.
B) adrenocorticotropic hormone.
C) oxytocin.
D) antidiuretic hormone.
E) luteinizing hormone.

Question 62

Which hormones are collectively called the gonadotropins?

A) Prolactin and oxytocin
B) Antidiuretic hormone and oxytocin
C) Follicle-stimulating hormone and luteinizing hormone
D) Follicle-stimulating hormone and growth hormone
E) Thyroid-stimulating hormone and adrenocorticotropic hormone

Question 63

Where are the target cells for follicle-stimulating hormone?

A) Thyroid follicles
B) Ovaries and testes
C) Mammary glands
D) Uterus
E) Hair follicles

Question 64

When follicular cells of the thyroid are stimulated to secrete thyroid hormone (TH), they take up TH precursors from the inside of the follicle, transport and enzymatically modify them within a lysosome, and release TH to the blood.

Question 65

Growth hormone is secreted by ________ cells in the anterior pituitary.

A) somatotropic
B) gonadotropic
C) thyrotropic
D) mammotropic
E) corticotropic

Question 66

Which is not true about the thyroid gland?

A) It requires iodine to synthesize thyroid hormone.
B) It is located on the anterior surface of the trachea, inferior to the thyroid cartilage.
C) It has two lobes connected by a central portion called the commissure.
D) It secretes thyroid hormone in response to stimulation by TSH.
E) An enlargement of the thyroid gland is called a goiter.

Question 67

Thyroid hormone synthesis involves secretion of a glycoprotein called ________ by the follicular cells.

A) colloid
B) thyroxine
C) triiodothyronine
D) thyroglobulin
E) tetraiodothyronine

Question 68

Exercise causes a(n) ________ in growth hormone (GH) levels; a rise in amino acid levels or decrease in glucose levels causes a(n) ________ in GH levels.

A) increase; increase
B) increase; decrease
C) decrease; decrease
D) decrease; increase

Question 69

Thyroid hormone's effects are to

A) increase metabolic rate and body temperature by increasing protein synthesis in target cells.
B) increase metabolic rate and body temperature by turning on the G protein, cAMP cascade.
C) decrease metabolic rate and body temperature by increasing protein synthesis in target cells.
D) decrease metabolic rate and body temperature by turning on the G protein, cAMP cascade.
E) increase metabolic rate and body temperature by turning off the G protein, cAMP cascade.

Question 70

Which is not correct regarding growth hormone (GH)?

A) GH affects most body cells.
B) GH stimulates cell growth and mitosis.
C) GH is also known as somatotropin.
D) GH stimulates the kidney to secrete somatomedin.
E) GH is a tropic hormone.

Question 71

Thyroid-stimulating hormone (TSH) is secreted by the

A) hypothalamus, and it targets cells of the posterior pituitary gland
B) hypothalamus, and it targets cells of the anterior pituitary gland.
C) anterior pituitary, and it targets follicular cells of the thyroid gland.
D) posterior pituitary, and it targets parafollicular cells of the thyroid gland.
E) thyroid gland, and it targets cells of the parathyroid gland.

Question 72

Growth hormone releasing hormone (GHRH) is one of the regulatory hormones released by the hypothalamus that acts on the pituitary.

Question 73

Which is not a tropic hormone?

A) Thyroid-stimulating hormone
B) Adrenocorticotropic hormone
C) Follicle-stimulating hormone
D) Prolactin

Question 74

Excessive secretion of growth hormone in adults can cause

A) Graves disease.
B) acromegaly.
C) pituitary gigantism.
D) pituitary dwarfism.
E) Cushing syndrome.

Question 75

Until thyroid hormone needs to be secreted, precursors to it are stored in a viscous, protein-rich fluid within the center of thyroid follicles. This viscous fluid is known as ________.

Question 76

The primary function of adrenocorticotropic hormone (ACTH) is to

A) regulate salt and water balance by acting on the renal system.
B) stimulate glucocorticoid release from the adrenal glands.
C) stimulate adrenaline release from the adrenal medulla.
D) stimulate cell growth and cell division in muscle and bone.
E) stimulate the development of the folds on the surface of the brain.

Question 77

The thyroid gland is located

A) anterior to the atria of the heart.
B) immediately anterior to the trachea.
C) immediately superior to the larynx.
D) immediately posterior to the cricoid cartilage.

Question 78

You are "shadowing" an endocrinologist who is examining a patient complaining of weakness, weight loss, and heat intolerance. The doctor points out the patient's obvious exophthalmos and asks for your diagnosis. What would you speculate is the patient's problem?

A) Hyposecretion of parathyroid hormone
B) Hypersecretion of parathyroid hormone
C) Hyposecretion of thyroid hormone
D) Hypersecretion of thyroid hormone
E) Hyposecretion of calcitonin

Question 79

Which region of the adrenal cortex synthesizes glucocorticoids?

A) Zona reticularis
B) Zona glucosa
C) Zona papillarosa
D) Zona fasciculata
E) Zona glomerulosa

Question 80

Which hormone group is not secreted by the adrenal cortex?

A) Corticosteroids
B) Glucocorticoids
C) Mineralocorticoids
D) Gonadocorticoids
E) No exceptions; all choices are secreted by the adrenal cortex