Question 1

Which of these statements does NOT apply to peptide hormones
A)They include adrenal cortex hormones.
B)They include insulin.
C)They are stored within secretory granules.
D)They are secreted from endocrine glands.

Accepted Answer

Adrenal cortex hormones are not peptide hormones, they are steroid hormones.

Question 2

A hormone can influence the activity of another hormone at a given target cell in one of three ways: permissiveness, synergism, or antagonism.Which of these statements demonstrates that concept
A)With permissiveness, one hormone must be present in adequate amounts for the full exertion of another hormone's effect.
B)Synergism occurs when the action of one hormone is more dominant than another hormone.
C)Antagonism occurs when hormones compete for the hormone's receptors.
D)ADH and oxytocin are a good example of antagonistic hormones.

Accepted Answer

Permissiveness occurs when one hormone must be present in adequate amounts for the full exertion of another hormone's effect. This statement describes the concept of permissiveness where the presence of one hormone (in adequate amounts) is necessary for the full effect of another hormone to be exerted.

Question 3

The transport of lipid-soluble hormones in the blood is accomplished by which of the following mechanisms
A)loose binding with iodine
B)specific binding to some plasma proteins
C)specific binding to HDLs
D)specific binding to glycolipids

Accepted Answer

Lipid-soluble hormones are hydrophobic and do not dissolve in blood plasma, which is mostly water. Therefore, they need to bind to some plasma proteins (such as albumin or sex hormone-binding globulin) to be transported in the blood. This binding provides a means of carrying the hormone through the watery bloodstream without affecting its chemical structure or decreasing its concentration. Loose binding with iodine and specific binding to HDLs or glycolipids are not mechanisms involved in the transport of lipid-soluble hormones in the blood.

Question 4

Which characteristic is NOT shared by both lipophilic and hydrophilic hormones
A)amplification of hormone actions in the target cell
B)passing through the lipid membrane barriers of their target cells
C)synergistic actions
D)antagonistic actions

Accepted Answer

Lipophilic hormones can pass through the lipid membrane barriers of their target cells because they are fat-soluble, whereas hydrophilic hormones cannot pass through lipid membranes directly due to their water solubility; they typically require a receptor on the cell surface to mediate their actions.

Question 5

Which of these statements describes amines
A)They consist of a chain of specific amino acids of varying length.
B)They are derived from alanine.
C)They include the hormones secreted by the thyroid gland and the adrenal medulla.
D)They are derived from tyrosine.

Accepted Answer

The answer of Which of these statements describes amines
A)They consist...

Question 6

Hormones are classified into which of the following three types
A)amines, peptides, and steroids
B)amides, steroids, and phospholipids
C)amines, phospholipids, and steroids
D)amides, amines, and peptides

Accepted Answer

Hormones can be broadly classified into three types based on their chemical structure - amines (derived from amino acids), peptides (short chains of amino acids), and steroids (lipids derived from cholesterol). Amides and phospholipids are not typically classified as hormones.

Question 7

Which class of hormones is synthesized by the endoplasmic reticulum-Golgi complex mechanism
A)peptides
B)catecholamines
C)steroids
D)thyroid hormones

Accepted Answer

Peptide hormones are synthesized by the endoplasmic reticulum-Golgi complex mechanism. This process involves the translation of hormone precursors in the rough ER, followed by post-translational modifications in the ER and Golgi apparatus before the mature hormones are secreted.

Question 8

Estrogens, testosterone, cortisol, and aldosterone are derivatives of which molecular precursor
A)DHEA
B)cholesterol
C)UDP-glucose
D)epinephrine

Accepted Answer

Estrogens, testosterone, cortisol, and aldosterone are all steroid hormones and derivatives of cholesterol.

Question 9

Which of the following happens in the second-messenger step
A)A small amount of one hormone (the second messenger) is required to release another.
B)A tropic hormone (the first messenger) stimulates secretion of another hormone (the second messenger).
C)The hormone first binds to a specific surface receptor, whereupon the hormone-receptor complex moves into the cell to combine with a specific intracellular receptor.
D)A hormone (the first messenger) binds to surface receptors, activating adenylyl cyclase, which catalyzes cAMP formation.

Accepted Answer

In the second-messenger step, a hormone (the first messenger) binds to surface receptors, which activates adenylyl cyclase, catalyzing cAMP formation. This second messenger (cAMP) then goes on to activate downstream signaling pathways that ultimately regulate cellular processes.

Question 10

Which class of hormones is released by exocytosis upon appropriate stimulation
A)peptides
B)thyroxin
C)steroids
D)insulins

Accepted Answer

Peptides are typically released by exocytosis upon stimulation. This is because peptide hormones are stored in vesicles within the cell and require a signal to trigger the release of the contents into the extracellular space. Examples of peptide hormones include insulin, glucagon, and growth hormone. Thyroxin and steroids are not released by exocytosis, as they are lipid-soluble and can diffuse directly out of the cell membrane.

Question 11

Which of these substances is NOT associated with the post-receptor events of hydrophilic hormones
A)cyclic AMP
B)protein kinase
C)adenylate cyclase
D)chromatin

Accepted Answer

Chromatin is not associated with the post-receptor events of hydrophilic hormones. The other three substances - cyclic AMP, protein kinase, and adenylate cyclase - are all involved in the signal transduction pathways that occur after hydrophilic hormones bind to their surface receptors.

Question 12

Which class of hormones triggers the synthesis of new intracellular proteins within the target cell
A)peptides
B)steroids
C)thyroid hormones
D)lipophilic hormones

Accepted Answer

The answer of Which class of hormones triggers the synthesis...

Question 13

Which statement does NOT refer to post-receptor events of hydrophilic hormones
A)Adenylyl cyclase forms cyclic AMP.
B)Cyclic AMP is a secondary messenger.
C)Some hydrophilic hormones use Ca ions as a secondary messenger.
D)Specific genes are activated.

Accepted Answer

The activation of specific genes refers to a post-receptor event of hydrophobic hormones, not hydrophilic hormones.

Question 14

Which of these statements applies to lipophilic hormones
A)They include catecholamines.
B)They activate second-messenger systems within their target cells.
C)They bind with receptors located inside their target cells.
D)They circulate as free hormones.

Accepted Answer

Lipophilic hormones are lipid soluble and can cross the cell membrane to bind with receptors located inside the target cells. This distinguishes them from lipophobic hormones, such as catecholamines, which cannot readily cross the cell membrane and instead bind with receptors located on the cell surface. Lipophilic hormones do not circulate as free hormones, as they require carrier proteins to transport them through the bloodstream to their target cells. They also do not activate second messenger systems within their target cells, as lipophobic hormones do, but instead interact with intracellular receptors to affect gene transcription and protein synthesis.

Question 15

Which class of hormones acts by means of a second-messenger system
A)catecholamines
B)proteins
C)steroids
D)thyroid hormones

Accepted Answer

Both catecholamines (such as epinephrine and norepinephrine) and proteins (such as insulin and growth hormone) act by means of a second-messenger system. This means that they bind to a receptor on the cell membrane, which then activates a second messenger within the cell (such as cyclic AMP or calcium ions) that ultimately triggers a cellular response. Steroids and thyroid hormones, on the other hand, bind directly to intracellular receptors and do not require a second messenger system.

Question 16

Lipophilic hormones interact with which of the following prior to gene activation
A)membrane receptors
B)cAMP
C)hormone response elements
D)G proteins

Accepted Answer

Lipophilic hormones such as steroid hormones directly enter the target cell and interact with hormone response elements (HREs) on the DNA to activate genes. They do not require membrane receptors, cAMP, or G proteins like lipophobic hormones do.

Question 17

Which of these hormone types does NOT require membrane receptors to invoke cell responses
A)catecholamines
B)steroids
C)peptides
D)parathyroid hormones

Accepted Answer

Steroids are lipid-soluble and can pass through cell membranes to bind with intracellular receptors, unlike catecholamines, peptides, and parathyroid hormones, which are not lipid-soluble and thus require membrane receptors to mediate their actions.

Question 18

Which of these statements applies to steroids
A)They are hydrophilic.
B)Epinephrine is an example of a steroid.
C)They initiate synthesis of the second messenger system within their target cells.
D)They are derived from cholesterol.

Accepted Answer

Steroids are a class of lipids that are derived from cholesterol. They are hydrophobic and do not initiate the second messenger system. Epinephrine is not a steroid, it is a hormone.

Question 19

Which of these statements does NOT apply to peptide hormones
A)They are synthesized by the endoplasmic reticulum-Golgi complex system.
B)They bind to surface receptors of their target cells.
C)They circulate bound largely to plasma proteins.
D)They exert their effect largely by means of second-messenger systems.

Accepted Answer

Peptide hormones are generally water-soluble and circulate freely in the plasma, not bound largely to plasma proteins. This characteristic contrasts with steroid hormones, which are lipid-soluble and do circulate bound to plasma proteins.

Question 20

Which of these substances is the most common second messenger used by hydrophilic hormones
A)calcium
B)cyclic AMP
C)chromatin
D)messenger RNA

Accepted Answer

Cyclic AMP (cAMP) is the most common second messenger used by hydrophilic hormones. When a hydrophilic hormone binds to its receptor on the cell membrane, it triggers the activation of an enzyme called adenylate cyclase, which converts ATP into cAMP. cAMP then activates protein kinase A (PKA), which triggers a cascade of biochemical reactions that ultimately lead to the cellular response to the hormone signal. Calcium is also a common second messenger, but it is typically used by G protein-coupled receptors that activate phospholipase C instead of adenylate cyclase. Chromatin and messenger RNA are not involved in second messenger signaling.

Quiz 5: Principles of Endocrinology: The Central Endocrine Glands

Which of these statements does NOT apply to peptide hormones

A hormone can influence the activity of another hormone at a given target cell in one of three ways: permissiveness, synergism, or antagonism.Which of these statements demonstrates that concept

The transport of lipid-soluble hormones in the blood is accomplished by which of the following mechanisms

Which characteristic is NOT shared by both lipophilic and hydrophilic hormones

Which of these statements describes amines

Hormones are classified into which of the following three types

Which class of hormones is synthesized by the endoplasmic reticulum-Golgi complex mechanism

Estrogens, testosterone, cortisol, and aldosterone are derivatives of which molecular precursor

Which of the following happens in the second-messenger step

Which class of hormones is released by exocytosis upon appropriate stimulation

Which of these substances is NOT associated with the post-receptor events of hydrophilic hormones

Which class of hormones triggers the synthesis of new intracellular proteins within the target cell

Which statement does NOT refer to post-receptor events of hydrophilic hormones

Which of these statements applies to lipophilic hormones

Which class of hormones acts by means of a second-messenger system

Lipophilic hormones interact with which of the following prior to gene activation

Which of these hormone types does NOT require membrane receptors to invoke cell responses

Which of these statements applies to steroids

Which of these statements does NOT apply to peptide hormones

Which of these substances is the most common second messenger used by hydrophilic hormones