Deck 11: Endocrine Glands: Secretion and Action of Hormones

Question 1

Endocrine glands secrete their products into ducts.

Answer 1

False

Question 2

Hormones which enhance the responsiveness of a target organ to a second hormone have

A)complementary effects.
B)synergistic effects.
C)antagonistic effects.
D)permissive effects.

Answer 2

D

Question 3

Melatonin can pass through plasma membranes since it is derived from the nonpolar amino acid tryptophan.

Answer 3

True

Question 4

Which of the following is NOT a polypeptide or glycoprotein hormone

A)cortisol
B)glucagon
C)antidiuretic hormone
D)parathyroid hormone

Question 5

Dual glands,like the pancreas,have both endocrine and exocrine functions.

Question 6

A chronically high hormone concentration often leads to an increased receptor number.

Question 7

Which of the following is the most senior precursor molecule?

A)a prehormone
B)a prohormone
C)a hormone
D)a hormone receptor

Question 8

When two or more hormones work together to produce a particular result,their effects are

A)permissive.
B)antagonistic.
C)synergistiC.
D)inhibitory.

Question 9

Biologically active molecules in the blood are called hormones.

Question 10

The neurons from the hypothalamus secrete chemicals calledneurohormones.

Question 11

Most polypeptide and protein hormones are synthesized as prohormones.

Question 12

Responsiveness of cells to hormones is determined by the presence or absence of specific hormone receptor proteins.

Question 13

Many polypeptide and glycoprotein hormones are secreted in discrete bursts called pulsatile secretions.

Question 14

Most lipid-soluble hormones are derived from cholesterol.

Question 15

Small amounts of a polypeptide or glycoprotein hormone may cause

A)upregulation of receptors.
B)increased numbers of receptors placed in the plasma membrane.
C)the priming effect.
D)All of the choices are correct.

Question 16

Polypeptide and glycoprotein hormones can be taken orally.

Question 17

Polypeptide hormones are synthesized from tyrosine and tryptophan.

Question 18

Which of the following is NOT true about a chemical functioning in physiological regulation

A)There must be a mechanism to turn off the chemical's action.
B)The chemicals must be secreted by endocrine glands.
C)Target cell must have specific receptor molecules for the chemical.
D)The combination of the chemical and its receptor must cause specific changes to occur in the target cell.

Question 19

Those hormones that are nonpolar can pass through the plasma membrane and are calle

A)hydrophilic.
B)hydrophobic.
C)lipophiliC.
D)Both hydrophobic and lipophilic are correct.

Question 20

Molecules secreted by endocrine glands that are inactive until changed by their target cells are

A)prohormones.
B)lipophilic hormones.
C)prehormones.
D)tissue hormones.

Question 21

Lipophilic hormones travel in the blood bonded to carrier proteins.

Question 22

Lipophilic hormones and thyroid hormone are transported to their target cells free in the plasma.

Question 23

Which of the following is a selective estrogen receptor modulator?

A)tamoxifen.
B)raloxifene.
C)progesterone.
D)Both tamoxifen and raloxifene.

Question 24

Testosterone receptors would be ____________ in response to anabolic steroid abuse

A)inhibited
B)primed
C)upregulated
D)downregulated

Question 25

Pharmacological concentrations of hormones causes normal tissue responses.

Question 26

Steroid hormone receptors form a ____ on their DNA half-sites.

A)homodimer
B)autodimer
C)pseudodimer
D)heterodimer

Question 27

To induce full cellular effects,thyroid hormones also require the actions of

A)adrenocorticotropin.
B)melatonin.
C)9-cis-retinoic acid.
D)somatomedins.

Question 28

How is most thyroid hormone transported in the plasma?

A)as T₄ bonded to globulin
B)as T₃ bonded to globulin
C)as free T₄
D)as free T₃

Question 29

The process of two steroid hormones binding to their nuclear receptors at two half-sites on DNA to initiate transcription is called

A)synergism.
B)antagonism.
C)translocation.
D)dimerization.

Question 30

Carrier proteins would be required by

A)aldosterone.
B)cholecystokinin.
C)follicle stimulating hormone.
D)prolactin.

Question 31

Thyroid hormone receptors form a ___ on their DNA half-sites.

A)homodimer
B)autodimer
C)pseudodimer
D)heterodimer

Question 32

Proteins that must bind to a nuclear receptor protein that aids in its activation are called

A)homodimers.
B)corepressors.
C)orphan receptors.
D)coactivators.

Question 33

Hormone receptors have a high capacity and a low affinity.

Question 34

Thyroid hormones bind to receptors which

A)activate tyrosine kinase.
B)regulate gene transcription.
C)stimulate production of cyclic AMP.
D)stimulate production of diacylglycerol.

Question 35

Steroid hormone influence on gene expression is known as

A)genomic action
B)nongenomic ation.
C)dimerization.
D)translocation.

Question 36

Water-soluble hormones bind to receptors located within the plasma membrane.

Question 37

Lipophilic hormones interact with receptors that are transcription factors.

Question 38

Nuclear receptors that have been identified and their genes cloned,but their hormone ligands are unknown are called

A)transcription factors.
B)unknown ligands.
C)orphan receptors.
D)nongenomic receptors.

Question 39

Thyroid hormone receptor proteins are found

A)on the plasma membrane.
B)in the cytoplasm.
C)in the nucleus.
D)All of the choices are correct.

Question 40

Steroid hormone receptors may be found

A)in the cytoplasm.
B)in the nucleus.
C)on the cell surface.
D)Both in the cytoplasm and in the nucleus.

Question 41

Many growth factors use

A)cyclic AMP as a second messenger.
B)tyrosine kinase as a second messenger.
C)calmodulin as a second messenger.
D)cyclic GMP as a second messenger.

Question 42

Binding of epinephrine to beta-adrenergic receptors in the plasma membrane will activate the ______ second messenger system.

A)calcium
B)IP₃
C)adenylate cyclase (cAMP)
D)DAG

Question 43

Mutation of the calmodulin gene would alter the ability of ____________ to act as a second messenger.

A)calcium
B)sodium
C)potassium
D)cAMP

Question 44

Activated calmodulin will,in turn,activate protein kinases.

Question 45

In the phospholipase C mechanism,most of the increased intracellular calcium comes from

A)outside the cell.
B)within the plasma membrane.
C)the endoplasmic reticulum.
D)extracellular fluiD.

Question 46

G-proteins are needed to directly stimulate the activation of protein kinase.

Question 47

Protein kinase catalyzes the ___________ of other enzymes in the cytoplasm.

A)hydrolysis
B)phosphorylation
C)synthesis
D)decarboxylation

Question 48

Epinephrine can act through two second-messenger systems (cAMP and Ca²⁺).

Question 49

Which of the following directly initiates the release of calcium ions from the endoplasmic reticulum?

A)G-proteins
B)phospholipase C
C)inositol triphosphate (IP₃)
D)calmodulin

Question 50

Plasma levels of protein-bound thyroxine fluctuate greatly in response to the body's use of thyroxine.

Question 51

cAMP activates ______ that activates other enzymes in the cell.

A)protein kinase
B)calcium
C)calmodulin
D)tyrosine kinase

Question 52

Second messengers generated by the actions of phospholipase C

A)are inhibited by the actions of caffeine.
B)are stimulated by phosphodiesterases.
C)may activate calmodulin.
D)stimulate gene transcription.

Question 53

All protein-bound T₄ is released to enter the target cells.

Question 54

Inhibition of G-proteins would cause an increase in hormone-induced intracellular Ca²⁺ concentrations.

Question 55

Which of the following is NOT a second messenger system activated by lipophobic hormones?

A)9-cis-retinoic acid
B)tyrosine kinase
C)adenylate cyclase
D)phospholipase C

Question 56

Caffeine raises intracellular cAMP concentrations by inhibiting phosphodiesterase.

Question 57

Cellular actions of insulin could be inhibited by

A)decreasing intracellular calmodulin.
B)stimulating protein kinase activity.
C)inhibiting translation.
D)inhibiting receptor phosphorylation.

Question 58

Inhibition of phosphodiesterase would potentially increase the effects of hormones that activate adenylate cyclase.

Question 59

What is the action of the signaling molecules activated by the insulin-tyrosine kinase second messenger system?

A)insertion of glucose carrier proteins into the plasma membrane
B)hydrolysis of glycogen and secretion of glucose
C)transport of insulin into the cell
D)All of the choices are correct.

Question 60

Viagra is a drug that creates penile erection by

A)indirectly decreasing the breakdown of cGMP.
B)indirectly increasing cGMP production.
C)directly decreasing nitric oxide levels.
D)directly increasing nitric oxide levels.

Question 61

What is the function of prolactin in females?

A)stimulates milk production in the mammary glands
B)regulates the gonadotropins
C)regulates water and electrolyte balance in the kidneys
D)All of the choices and correct.

Question 62

Prolactin injections may be used to induce labor.

Question 63

The posterior pituitary gland produces two hormones.

Question 64

The anterior pituitary gland is also called the neurohypophysis.

Question 65

Higher brain centers can influence pituitary secretions and therefore the target organ through the pituitary-target organ axis.

Question 66

Pheromones act through the gustatory sense to modify the physiology or behavior of another member of the same species.

Question 67

Protein synthesis is usually stimulated when luteinizing hormone binds to its receptor.

Question 68

Regulation of mineral homeostasis would be inhibited due to decreased secretion of

A)corticotropin releasing hormone.
B)dopamine.
C)gondadotropin releasing hormone.
D)growth hormone releasing hormone.

Question 69

The hypothalamus,anterior pituitary gland,and the various target glands control the functions of each other,so there is no "master gland."

Question 70

Oxytocin synthesis occurs in the neurohypophysis.

Question 71

Cortisol secretion would cease if the _________ no longer secreted ACTH.

A)posterior pituitary gland
B)hypothalamus
C)anterior pituitary gland
D)adrenal cortex

Question 72

Elevated secretion of ACTH,as in Addison's disease,causes a darkening of the skin because ACTH is related to MSH which causes production of the pigment melanin.

Question 73

Growth would be inhibited by

A)increasing prolactin secretion.
B)increasing somatostatin secretion.
C)increasing somatomedin secretion.
D)increasing thyroid hormone secretion.

Question 74

Inhibition of luteinizing hormone secretion would inhibit testosterone synthesis.

Question 75

Pituitary dwarfism is caused by growth years hyposecretion of growth hormone.

Question 76

Adenohypophyseal function is regulated by the hypothalamus.

Question 77

The vascular link between the hypothalamus and the __________ is called the hypothalamo-hypophyseal portal system.

A)posterior pituitary
B)anterior pituitary
C)pineal gland
D)thalamus

Question 78

Increased circulating concentrations of testosterone would stimulat

A)decreased secretion of growth hormone.
B)decreased secretion of adrenocorticotropin.
C)decreased secretion of luteinizing hormone.
D)decreased secretion of thyroid stimulating hormone.

Question 79

Most target organ control on the anterior pituitary gland is due to

A)positive feedback effect.
B)negative feedback.
C)negative feedback inhibition.
D)positive feedback inhibition.

Question 80

Adrenocorticotropic hormone is synthesized in cells that had been part of th

A)the pars distalis.
B)the pars tuberalis.
C)the pars intermedia.
D)the neurohypophysis.