Deck 11: Endocrine Glands: Secretion and Action of Hormones

Question 1

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

Answer 1

True

Question 2

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

Answer 2

True

Question 3

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

Answer 3

True

Question 4

Endocrine glands secrete their products into ducts.

Question 5

The neurons from the hypothalamus secrete chemicals called neurohormones.

Question 6

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.

Question 7

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 8

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

Question 9

Which of the following is the most senior precursor molecule?

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

Question 10

Polypeptide hormones are synthesized from tyrosine and tryptophan.

Question 11

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

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

Question 12

Most polypeptide and protein hormones are synthesized as prohormones.

Question 13

Polypeptide and glycoprotein hormones can be taken orally.

Question 14

Which of the following is NOT a polypeptide or glycoprotein hormone

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

Question 15

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

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

Question 16

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

Question 17

Biologically active molecules in the blood are called hormones.

Question 18

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 apply.

Question 19

Most lipid-soluble hormones are derived from cholesterol.

Question 20

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 21

Which of the following is a selective estrogen receptor modulator?

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

Question 22

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 23

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

Question 24

Lipophilic hormones travel in the blood bonded to carrier proteins.

Question 25

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

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

Question 26

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 27

Carrier proteins would be required by

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

Question 28

Steroid hormone influence on gene expression is known as

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

Question 29

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

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

Question 30

Testosterone receptors would be ____________ in response to anabolic steroid abuse

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

Question 31

Lipophilic hormones interact with receptors that are transcription factors.

Question 32

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 33

Hormone receptors have a high capacity and a low affinity.

Question 34

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 35

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 36

Thyroid hormone receptor proteins are found

A)on the plasma membrane.
B)in the cytoplasm.
C)in the nucleus.
D)All apply.

Question 37

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 38

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

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

Question 39

Pharmacological concentrations of hormones causes normal tissue responses.

Question 40

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

Question 41

cAMP activates ______ that activates other enzymes in the cell.

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

Question 42

Caffeine raises intracellular cAMP concentrations by inhibiting phosphodiesterase.

Question 43

Activated calmodulin will,in turn,activate protein kinases.

Question 44

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 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

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 47

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 48

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 49

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

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

Question 50

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 apply.

Question 51

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

Question 52

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

Question 53

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 54

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

Question 55

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

Question 56

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 57

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 58

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 59

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

Question 60

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

Question 61

Oxytocin synthesis occurs in the neurohypophysis.

Question 62

Increased circulating concentrations of testosterone would stimulate

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 63

Growth would be inhibited by

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

Question 64

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 65

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 apply.

Question 66

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

Question 67

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

Question 68

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 69

The posterior pituitary gland produces two hormones.

Question 70

The anterior pituitary gland is also called the neurohypophysis.

Question 71

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

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

Question 72

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 73

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 74

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

Question 75

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

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

Question 76

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

Question 77

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

Question 78

Inhibition of luteinizing hormone secretion would inhibit testosterone synthesis.

Question 79

Prolactin injections may be used to induce labor.

Question 80

Adenohypophyseal function is regulated by the hypothalamus.