Deck 17: Functional Organization of the Endocrine System

Question 1

Hormones with short half-lives

A) are usually lipid-soluble.
B) are maintained at relatively constant levels.
C) have concentrations that increase slowly.
D) regulate activities of delayed onset and long duration.
E) regulate activities of rapid onset and short duration.

Answer 1

E

Question 2

An intercellular chemical signal that is produced by neurons but functions like a hormone would be called a ________.

A) neuropathogen
B) neurotransmitter
C) neurocrine
D) neuropeptide
E) neurosynthesizer

Answer 2

D

Question 3

Which type of chemical messenger will act locally on nearby cells?

A) Paracrine
B) Neurotransmitter
C) Autocrine
D) Endocrine

Answer 3

A

Question 4

Which chemical type of hormone has a longer half-life?

A) Lipid-soluble
B) Protein
C) Water-soluble
D) Amino acid derivative

Question 5

What do all hormones have in common?

A) They are made from amino acids.
B) They are bound to transport molecules in the blood.
C) They bind to and interact with a receptor on or in the target cell.
D) They use the second messenger mechanism to control the target cell.
E) They are all lipid-soluble.

Question 6

Hormones are intercellular chemical signals that

A) are secreted into the external environment where they act.
B) affect only non-hormone producing organs or tissues.
C) help coordinate growth, development and reproduction.
D) operate primarily by positive feedback.

Question 7

In general, the response of target cells to endocrine stimulation is ________ than their response to nervous stimulation.

A) faster and briefer
B) slower and more prolonged
C) more accurate
D) more restricted to a small area of the body
E) more intense

Question 8

What is it about a cell that identifies it as a target cell for a hormone?

A) The presence of a receptor specific for that hormone
B) Its location near the gland that secretes that hormone
C) The ability of the target cell to perform a specific function
D) Its ability to inactivate the hormone
E) The size of the target cell

Question 9

Most endocrine glands communicate with their target tissues using ________ signals.

A) frequency-modulated
B) amplitude-modulated
C) pitch-modulated
D) resonance-modulated

Question 10

Lipid-soluble hormones can be more easily excreted once they have water-soluble molecules added to their structure in a process called ________.

A) saponification
B) amplitude-modulation
C) conjugation
D) protein-binding

Question 11

Members of which group of hormones are made from cholesterol?

A) Amino acid derivatives
B) Peptides
C) Proteins
D) Steroids

Question 12

Given the following list of organic molecules, which includes hormones? 1) Nucleic acid derivatives 2) Polypeptides 3) Steroids 4) Proteins

A) 1, 3, 4
B) 1, 2, 3
C) 2, 3, 4
D) 1, 2, 3, 4
E) 1, 2, 4

Question 13

Which chemical class of hormone is more likely to need a binding protein for transport in the blood?

A) Water-soluble
B) Amino acid derivative
C) Protein
D) Lipid-soluble

Question 14

Which type of chemical messenger stimulates the cell that originally secreted it?

A) Paracrine
B) Neurotransmitter
C) Autocrine
D) Endocrine

Question 15

Once a lipid-soluble hormone is conjugated in the liver

A) its half-life is increased.
B) it can be more quickly eliminated from the body.
C) it can be stored for later use.
D) it is actively transported into cells.
E) it is more slowly eliminated from the body.

Question 16

Which type of chemical messenger is released from neurons to activate an adjacent cell?

A) Paracrine
B) Neurotransmitter
C) Autocrine
D) Endocrine

Question 17

The half-life of a hormone allows one to determine

A) the rate of hormone secretion.
B) the identity of a hormone.
C) the rate at which hormones are eliminated from the body.
D) the rate of action of a hormone.
E) the rate of travel through the blood to a target.

Question 18

The endocrine system

A) releases neurotransmitters into ducts.
B) secretes chemicals that reach their targets through the bloodstream.
C) communicates via frequency-modulated signals.
D) contains organs called exocrine glands.
E) is isolated from the nervous system.

Question 19

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

A) The hypothalamus is important to both the nervous and endocrine systems.
B) Both the nervous and endocrine systems may utilize the same chemical molecule.
C) Some neurons secrete hormones.
D) Both the nervous and endocrine systems respond quickly and are active for a long time.

Question 20

Which of the following statements regarding hormone transport and distribution is FALSE?

A) Only free hormones can diffuse through capillary walls and bind to target tissues.
B) Hormones can be transported free in the plasma or bound to plasma proteins.
C) Plasma protein concentration has no influence on free hormone concentration.
D) Hormones bind only to certain types of plasma proteins.
E) All of the statements are true.

Question 21

Which pattern of hormone secretion, represented by epinephrine, can have dramatic changes in its concentration and circulating levels?

A) Chronic hormone secretion
B) Long-term hormone secretion
C) Episodic hormone secretion
D) Acute hormone secretion

Question 22

Secretion of one hormone by the action of another hormone is control by ________ stimuli.

A) hormonal
B) neural
C) humoral
D) visceral

Question 23

When a hormone binds to a membrane-bound receptor,

A) membrane channels are destroyed.
B) cyclic GMP might be produced to act as an intracellular mediator.
C) the nucleus is phosphorylated to prevent G-protein activation.
D) messenger RNA is formed.
E) cellular DNA is altered.

Question 24

Receptors for most water-soluble hormones are located

A) in the cytoplasm of their target cells.
B) on the plasma membrane of their target cells.
C) in the lysosomes of their target cells.
D) on the nuclear membrane of their target cells.
E) on the endoplasmic reticulum of their target cells.

Question 25

Which pattern of hormone secretion, exemplified by thyroid hormones, remains relatively constant over long periods of time?

A) Acute hormone secretion
B) Episodic hormone secretion
C) Chronic hormone secretion
D) Long-term hormone secretion

Question 26

In some forms of diabetes, an insensitivity to insulin seems to be present. This insensitivity could be the result of ________.

A) up-regulation
B) over-regulation
C) down-regulation
D) a lack of regulation
E) modulation

Question 27

Hormone receptor molecules may be ________ in order to change the target cell's sensitivity to a given hormone.

A) increased in number
B) decreased in number
C) chemically altered
D) All the choices are correct.

Question 28

The role of cAMP when it acts as an intracellular mediator in cells is to

A) bind to and activate protein kinase.
B) directly activate genes in the nucleus to produce mRNA by binding to DNA.
C) directly activate structural enzymes in the cytoplasm of the target cell.
D) catalyze a cascade reaction that ultimately activates genes on the DNA.
E) control levels of calcium in the cell.

Question 29

Hormonal secretion can be regulated by

A) the action of a substance other than a hormone.
B) the nervous system.
C) other hormones.
D) All of the choices are correct.
E) None of the choices are correct.

Question 30

In general, lipid-soluble hormones exhibit which type(s) of hormone secretion pattern(s)?

A) Chronic hormone secretion
B) Chronic and acute hormone secretion
C) Acute and episodic hormone secretion
D) Episodic hormone secretion
E) Chronic and episodic hormone secretion

Question 31

Most hormones are regulated by ________ mechanisms.

A) negative-feedback
B) neural-feedback
C) positive-feedback
D) hormonal-feedback

Question 32

Receptors for most lipid-soluble hormones are located

A) in the cytoplasm of their target cells.
B) on the plasma membrane of their target cells.
C) in the lysosomes of their target cells.
D) on the nuclear membrane of their target cells.
E) in the nucleus or cytoplasm of their target cells.

Question 33

Parathyroid hormone is released when blood calcium levels decrease. This is an example of control by ________ stimuli.

A) hormonal
B) neural
C) humoral
D) visceral

Question 34

Cortisol, a lipid-soluble hormone is released into the blood. Predict what cortisol might do.

A) Cortisol will dissolve in the blood as free hormone.
B) Cortisol needs fenestrated capillaries to move out of the blood stream.
C) Cortisol will readily diffuses through capillary wall.
D) Cortisol will be rapidly degraded by proteases in the bloodstream.
E) Cortisol may have carbohydrates attached to give a longer half-life.

Question 35

Which pattern of hormone secretion, often observed in steroid reproductive hormones, will fluctuate over a monthly cycle?

A) Acute hormone secretion
B) Episodic hormone secretion
C) Long-term hormone secretion
D) Chronic hormone secretion

Question 36

How do hormones and target cells recognize one another?

A) By signs
B) By the location of the target cells
C) By the presence of specific receptor molecules on or in the target cells
D) By the function of the target cells
E) By the location of the hormones

Question 37

How do most water-soluble hormones travel in the bloodstream?

A) Attached to proteins
B) Attached to carbohydrates
C) Attached to amino acids
D) As free hormones

Question 38

A water-soluble hormone binds to its receptor on the plasma membrane. Arrange the events that follow in correct sequence.
(1) Alpha subunit-GTP complex alters cell activity
(2) GTP binds to the alpha subunit replacing GDP
(3) G-protein subunits separate from the receptor
(4) Alpha subunit separates from other two subunits
(5) G-protein subunits bind to the receptor

A) 5, 2, 3, 4, 1
B) 4, 2, 1, 3, 5
C) 5, 2, 1, 4, 3
D) 5, 4, 2, 1, 3
E) 3, 4, 1, 2, 5

Question 39

Which of the following is a regulatory protein associated with membrane-bound receptor molecules?

A) ATP
B) Calcium
C) M protein
D) G protein
E) DNA

Question 40

Up-regulation

A) results in a decrease in the number of receptor sites in the target cell.
B) produces an increase in the sensitivity of the target cell to the hormone.
C) is found in target cells that maintain a constant level of receptors.
D) produces insensitivity to the hormone in the target tissue.
E) moves the receptors up on the membrane.

Question 41

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
Cyclic AMP or cyclic GMP involved

Question 42

Match the chemical signal with the appropriate description.
A. Chemicals produced by neurons that function as hormones
B. Chemicals that act locally on nearby cells
C. Chemical secreted by presynaptic terminal
D. Influences same cell type from which it is secreted
E. Chemical secreted into blood by specialized cells; travels some distance to target tissues
Neuropeptide

Question 43

Match the chemical signal with the appropriate description.
A. Chemicals produced by neurons that function as hormones
B. Chemicals that act locally on nearby cells
C. Chemical secreted by presynaptic terminal
D. Influences same cell type from which it is secreted
E. Chemical secreted into blood by specialized cells; travels some distance to target tissues
Neurotransmitter

Question 44

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
Intracellular mediator

Question 45

Which of the following occurs when a hormone binds to a nuclear receptor?

A) Activation of cyclic AMP
B) Activation of mRNA synthesis
C) Increased lipid synthesis by ribosomes
D) Opens membrane channels
E) Alters membrane permeability

Question 46

When a few intracellular mediator molecules activate several enzymes, and each of these activated enzymes activate still other enzymes, the hormone has initiated ________.

A) a cascade effect
B) a double loop effect
C) a protein kinase effect
D) a cyclic effect
E) a negative feedback cycle

Question 47

Which of the following events occurs last?

A) IP₃ (inositol triphosphate) is produced.
B) Epinephrine combines with membrane-bound receptor on smooth muscle cell.
C) Calmodulin binds to the enzyme that phosphorylates myosin and cross-bridges form.
D) IP₃ stimulates Ca²⁺ release from the endoplasmic reticulum.
E) Ca²⁺ binds with calmodulin.

Question 48

Steroid hormones

A) bind to membrane receptors.
B) diffuse easily through the plasma membrane.
C) act by activating cAMP.
D) are inactivated by phosphodiesterase.
E) are water soluble.

Question 49

Phosphodiesterase functions

A) as a membrane-bound receptor molecule.
B) to inactivate cyclic AMP.
C) to attach phosphate groups to enzymes.
D) to combine GTP with cyclic AMP.
E) activates cGMP.

Question 50

Match the chemical signal with the appropriate description.
A. Chemicals produced by neurons that function as hormones
B. Chemicals that act locally on nearby cells
C. Chemical secreted by presynaptic terminal
D. Influences same cell type from which it is secreted
E. Chemical secreted into blood by specialized cells; travels some distance to target tissues
Autocrine

Question 51

Which type of hormone-receptor action allows insulin to move glucose into cells?

A) Activation of cGMP
B) Activation of adenylate cyclase
C) Direct alteration of intracellular enzymes
D) Phosphorylation of intracellular proteins

Question 52

When a hormone binds to a membrane-bound receptor and activates G proteins,

A) ion channels could be opened.
B) IP₃ may be activated.
C) cyclic AMP production may be increased.
D) DAG may be activated.
E) All of the choices are correct.

Question 53

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
Used by most lipid-soluble hormones

Question 54

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
Receptor molecule interacts with DNA

Question 55

Match the chemical signal with the appropriate description.
A. Chemicals produced by neurons that function as hormones
B. Chemicals that act locally on nearby cells
C. Chemical secreted by presynaptic terminal
D. Influences same cell type from which it is secreted
E. Chemical secreted into blood by specialized cells; travels some distance to target tissues
Paracrine

Question 56

Considering the following events in the nuclear receptor model, identify which of these events occurs in the nucleus.
(1) Hormone receptor complex binds to DNA.
(2) Messenger RNA directs synthesis of specific proteins.
(3) Hormone binds to receptors in the nucleus (sometimes in the cytoplasm).
(4) Messenger RNA synthesis is activated.
(5) Synthesized proteins produce the response of the cell.

A) 1, 3, 5
B) 1, 3, 4
C) 1, 2, 3
D) 3, 4, 5
E) All events occur in the nucleus.

Question 57

Which intracellular mediator is directly activated by the binding of a water-soluble hormone to a membrane receptor?

A) cGMP
B) cAMP
C) Calmodulin
D) Phospholipase C

Question 58

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
G-protein

Question 59

Arrange the following events in proper sequence:
(1) The activating hormone interacts with a membrane-bound receptor.
(2) Cyclic AMP causes the cell to carry out a function characteristic for that specific hormone.
(3) Adenylyl cyclase catalyzes the transformation of ATP to cyclic AMP.
(4) Adenylyl cyclase is activated.

A) 1, 2, 3, 4
B) 1, 4, 3, 2
C) 3, 4, 2, 1
D) 1, 3, 2, 4
E) 1, 3, 4, 2

Question 60

Match the chemical signal with the appropriate description.
A. Chemicals produced by neurons that function as hormones
B. Chemicals that act locally on nearby cells
C. Chemical secreted by presynaptic terminal
D. Influences same cell type from which it is secreted
E. Chemical secreted into blood by specialized cells; travels some distance to target tissues
Endocrine

Question 61

The release of chemicals from an endocrine or exocrine gland is referred to as ________.

A) absorption
B) diffusion
C) filtration
D) secretion

Question 62

Blood chemistry changes are examples of ________ stimuli, whereas sympathetic nervous system impulses are examples of ________ stimuli for hormone release.

A) neural; humoral
B) positive; negative
C) negative; positive
D) humoral; neural

Question 63

________ chemical signals are released by cells and affect other cell types locally without being transported in blood.

Question 64

Increased testosterone levels reduce the secretion of gonadotropin-releasing hormone from the anterior pituitary. This is an example of

A) inhibition of hormone release by humoral stimuli.
B) inhibition of hormone release by neural stimuli.
C) inhibition of hormone release by external stimuli.
D) inhibition of hormonal release by environmental stimuli.
E) inhibition of hormone release by hormonal stimuli.

Question 65

The length of time needed to eliminate half of a dose of a hormone is called its ________.

Question 66

All of the following are reasons why some hormones need assistance to travel in the blood except

A) they are small enough to be easily digested by blood enzymes.
B) they are easily filtered from the blood into the kidney tubules.
C) they have low solubility in blood plasma due to their chemical nature.
D) they cannot dissolve in the blood because they are water-soluble.

Question 67

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
Membrane channels may be opened or closed

Question 68

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
Generally observe a latent period

Question 69

All of the following chemical messengers may be listed in multiple functional classes except ________.

A) eicosanoids
B) epinephrine
C) prostaglandins
D) acetylcholine

Question 70

A chemical produced in a cell that activates specific processes in response to a hormone interaction with a membrane-bound receptor is referred to as a/an ________.

A) hormone response element
B) transcription factor
C) messenger RNA
D) intracellular mediator

Question 71

Emily is in labor with her first child. The amplitude-modulated system would show her oxytocin levels ________.

A) to have a weak signal
B) to have a moderate signal
C) to have a strong signal
D) too weak to measure

Question 72

Thyroid hormones (TH) normally travel in the blood both free and bound to TH-binding proteins. What would you expect to see in the blood work of a patient who had a deficiency of TH-binding protein?

A) Normal free TH levels and low bound TH levels
B) Low free TH levels and low bound TH levels
C) Low free TH levels and normal bound TH levels
D) Normal free TH levels and normal bound TH levels

Question 73

Match the description with the type of receptor model.
A. Nuclear receptor model
B. Membrane-bound receptor model
Messenger RNA synthesis regulated

Question 74

All of the following are water-soluble hormones except ________.

A) growth hormone
B) insulin
C) thyrotropin-releasing hormone
D) thyroid-stimulating hormone
E) thyroid hormone

Question 75

Hormones act on specific tissues called ________ tissues.

Question 76

Secretion of the hormones ________ and ________ exemplify the pattern of chronic hormone secretion.

A) epinephrine; norepinephrine
B) insulin; glucagon
C) calcitonin; PTH
D) estrogen; progesterone
E) thyrotropin; thyroxine

Question 77

Increasing levels of thyroid hormones decrease TSH levels. This is an example of ________ feedback.

Question 78

All of the following are characteristics of hormones except

A) hormones alter activity in target cells.
B) hormones interact specifically with receptors.
C) hormones are stable in blood until arrival at target cells.
D) hormones interact with any cells in contact with bloodstream.

Question 79

In ________, a cell increases the number of hormone receptors and becomes more sensitive to the hormone.

A) amplification
B) positive feedback
C) down-regulation
D) up-regulation

Question 80

Sympathetic neurons can serve as ________ stimuli for hormone release from certain endocrine organs.

A) autocrine
B) humoral
C) paracrine
D) neural