Endocrine structures derived from nervous tissue include the

Endocrine structures derived from nervous tissue include the

A) thymus and the thyroid.
B) ovaries and the testes.
C) liver and the pancreas.
D) anterior pituitary gland and the adrenal cortex.
E) posterior pituitary gland and the adrenal medulla.




Answer: E

Oxytocin and antidiuretic hormone are synthesized in the

Oxytocin and antidiuretic hormone are synthesized in the 

A) hypothalamus.
B) adenohypophysis.
C) anterior pituitary.
D) adrenal cortex.
E) posterior pituitary.






Answer: A

In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are

In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are 

A) prolactin and calcitonin.
B) prolactin and oxytocin.
C) follicle-stimulating hormone and luteinizing hormone.
D) luteinizing hormone and oxytocin.
E) prolactin and luteinizing hormone.






Answer: B

To prevent insect pests from maturing into reproducing adults, pest controllers use synthetic agonists of

To prevent insect pests from maturing into reproducing adults, pest controllers use synthetic agonists of 

A) ecdysone.
B) juvenile hormone.
C) oxytocin.
D) brain hormone.
E) prothoracic hormone.






Answer: B

A product of the anterior pituitary gland that causes color changes in its target cells is

A product of the anterior pituitary gland that causes color changes in its target cells is 

A) FSH.
B) LH.
C) TSH.
D) MSH.
E) ACTH.





Answer: D

Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates that prolactin

Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates that prolactin 

A) is a nonspecific hormone.
B) has a unique mechanism for eliciting its effects.
C) is an evolutionarily conserved hormone.
D) is derived from two separate sources.
E) interacts with many different receptor molecules.






Answer: C

The hypothalamus

The hypothalamus 

A) functions only as an endocrine target, by having lots of receptors on its cells.
B) functions only in neuronal transmission.
C) does not have any hormone receptors on its cells.
D) secretes tropic hormones that act directly on the gonads.
E) includes neurosecretory cells that terminate in the posterior pituitary.







Answer: E

If a person loses a large amount of water in a short period of time, he or she may die from dehydration. ADH can help reduce water loss through its interaction with its target cells in the

If a person loses a large amount of water in a short period of time, he or she may die from dehydration. ADH can help reduce water loss through its interaction with its target cells in the 

A) anterior pituitary.
B) posterior pituitary.
C) adrenal gland.
D) bladder.
E) kidney.






Answer: E

Portal blood vessels connect two capillary beds found in the

Portal blood vessels connect two capillary beds found in the 

A) hypothalamus and thalamus.
B) anterior pituitary and posterior pituitary.
C) hypothalamus and anterior pituitary.
D) posterior pituitary and thyroid gland.
E) anterior pituitary and adrenal gland.







Answer: C

The hypothalamus modulates hormone secretion by the anterior pituitary by means of

The hypothalamus modulates hormone secretion by the anterior pituitary by means of

A) peptide hormones.
B) steroid hormones.
C) electrical synapses.
D) neurotransmitters.
E) paracrine signals.







Answer: A

The interrelationships between the endocrine and the nervous systems are especially apparent in

The interrelationships between the endocrine and the nervous systems are especially apparent in 

A) a neuron in the spinal cord.
B) a steroid-producing cell in the adrenal cortex.
C) a neurosecretory cell in the hypothalamus.
D) a brain cell in the cerebral cortex.
E) a cell in the pancreas that produces digestive enzymes.







Answer: C

Based on their effects, which pair below would not be expected to be active at the same time and place?

Based on their effects, which pair below would not be expected to be active at the same time and place? 

A) prostaglandin F and nitric oxide
B) growth hormone and insulin-like growth factors
C) endocrine and exocrine glands
D) hormones and target cells
E) neurosecretory cells and neurotransmitters




Answer: A

During short-term starvation, most available fuel molecules are catabolized to provide energy for metabolism rather than being used as building blocks for growth and repair, a trade-off that is hormonally regulated by

During short-term starvation, most available fuel molecules are catabolized to provide energy for metabolism rather than being used as building blocks for growth and repair, a trade-off that is hormonally regulated by 

A) acetylcholine.
B) glucagon.
C) oxytocin.
D) antidiuretic hormone.
E) insulin.





Answer: B

During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of

During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of 

A) a negative feedback system.
B) a hormone that acts in an antagonistic way with another hormone.
C) a hormone that is involved in a positive feedback loop.
D) signal transduction immediately changing gene expression in its target cells.
E) the key role of the anterior pituitary gland in regulating uterine contraction.






Answer: C

Hormones that promote homeostasis

Hormones that promote homeostasis 

A) are not found as members of antagonistic signaling mechanisms.
B) travel to target cells without passage in the plasma.
C) utilize receptors that bind any hormone.
D) initiate signal transduction in the target cell without binding to receptors.
E) usually operate as part of a negative feedback system.




Answer: E

Suppose that substance X is secreted by one cell, travels via interstitial fluid to a neighboring cell, and produces an effect on that cell. All of the following terms could describe this substance except

Suppose that substance X is secreted by one cell, travels via interstitial fluid to a neighboring cell, and produces an effect on that cell. All of the following terms could describe this substance except 

A) paracrine signal.
B) neurotransmitter.
C) prostaglandin.
D) pheromone.
E) growth factor.






Answer: D

Nitric oxide and epinephrine

Nitric oxide and epinephrine 

A) both function as neurotransmitters.
B) both function as steroid hormones.
C) are both involved in the "fight-or-flight" response.
D) bind the same receptors.
E) both cause a reduction in the blood levels of glucose.






Answer: A

For hormones that homeostatically regulate cellular functions,

For hormones that homeostatically regulate cellular functions, 

A) negative feedback typically regulates hormone secretion.
B) the circulating level of a hormone is held constant through a series of positive feedback loops.
C) both lipid-soluble hormones and water-soluble hormones bind to intracellular protein receptors.
D) endocrine organs release their contents into the bloodstream via specialized ducts.
E) it is impossible to also have neural regulation of that system.







Answer: A

When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, then

When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, then 

A) the steroid and peptide hormones must use the same biochemical mechanisms.
B) the steroid and peptide hormones must bind to the same receptor protein.
C) the steroid hormones affect the synthesis of effector proteins, whereas peptide hormones activate effector proteins already present in the cell.
D) the steroid hormones affect the activity of certain proteins within the cell, whereas peptide hormones directly affect the processing of mRNA.
E) the steroid hormones affect only the release of proteins from the target cell, whereas peptide hormones affect only the synthesis of proteins that remain in the target cell.





Answer: C

Hormone X activates the cAMP second messenger system in its target cells. The greatest response by a cell would come from

Hormone X activates the cAMP second messenger system in its target cells. The greatest response by a cell would come from 

A) applying a molecule of hormone X to the extracellular fluid surrounding the cell.
B) injecting a molecule of hormone X into the cytoplasm of the cell.
C) applying a molecule of cAMP to the extracellular fluid surrounding the cell.
D) injecting a molecule of cAMP into the cytoplasm of the cell.
E) injecting a molecule of activated, cAMP-dependent protein kinase into the cytoplasm of the cell.




Answer: A

A chemical signal operating in a paracrine manner is one that

A chemical signal operating in a paracrine manner is one that 

A) is active at a neuronal synapse.
B) affects only the cells that synthesize the paracrine signal.
C) requires transport in the blood before it can act on its target cells.
D) evokes responses from all parts of the vascular system.
E) must move through the air before it reaches its target cells.




Answer: A

Endocrine glands that are sources of steroid hormones

Endocrine glands that are sources of steroid hormones 

A) secrete the steroids through ducts into the blood.
B) store those hormones in membrane-bound vesicles.
C) have a very short latency between steroid synthesis and steroid release.
D) are all controlled by the autonomic nervous system.
E) operate independently of other hormonal cuing systems.







Answer: C

Insect hormones and their receptors

Insect hormones and their receptors 

A) act independently of each other.
B) are a focus in pest-control research.
C) utilize cell-surface receptors only.
D) are active independently of environmental cues.
E) are not relevant to the study of steroid hormones.







Answer: B

Different body cells can respond differently to the same peptide hormones because

Different body cells can respond differently to the same peptide hormones because 

A) different target cells have different sets of genes.
B) each cell converts that hormone to a different metabolite.
C) a target cell's response is determined by the components of its signal transduction pathways.
D) the circulatory system regulates responses to hormones by routing the hormones to specific targets.
E) the hormone is chemically altered in different ways as it travels through the circulatory system.







Answer: C

The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that

The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that 

A) only its target cells get exposed to aldosterone.
B) only its target cells contain aldosterone receptors.
C) it is unable to enter nontarget cells.
D) nontarget cells destroy aldosterone before it can produce any effect.
E) nontarget cells convert aldosterone to a hormone to which they do respond.




Answer: B

A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone's

A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone's 

A) secretory cell.
B) plasma cell.
C) endocrine cell.
D) target cell.
E) regulatory cell.





Answer: D

Aspirin and ibuprofen both

Aspirin and ibuprofen both 

A) inhibit the synthesis of prostaglandins.
B) inhibit the release of nitric oxide, a potent vasodilator.
C) activate the paracrine signaling pathways that form blood clots.
D) stimulate the release of oxytocin.
E) stimulate vasoconstriction in the kidneys.





Answer: A

Ecdysone is a(n)

Ecdysone is a(n) 

A) peptide hormone.
B) amine derivative.
C) steroid hormone.
D) iodinated protein hormone made by the thyroid gland.
E) gaseous neurotransmitter.






Answer: C

Prostaglandins are local regulators whose chemical structure is derived from

Prostaglandins are local regulators whose chemical structure is derived from 

A) oligosaccharides.
B) fatty acids.
C) steroids.
D) amino acids.
E) nitric oxide.





Answer: B

A paracrine signal that relaxes smooth muscle cells is

A paracrine signal that relaxes smooth muscle cells is 

A) nitric oxide.
B) vitamin D.
C) testosterone.
D) cortisol.
E) antidiuretic hormone.







Answer: A

Which category of signal exerts its effects on target cells by binding to membrane-bound receptor proteins?

Which category of signal exerts its effects on target cells by binding to membrane-bound receptor proteins? 

A) neurohormones
B) estrogens
C) androgens
D) vitamin D
E) neurohormones, estrogens, androgens, and vitamin D







Answer: A

Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example of

Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example of 

A) an autocrine signal.
B) a paracrine signal.
C) an endocrine signal.
D) both an autocrine signal and a paracrine signal.
E) an autocrine signal, a paracrine signal, and an endocrine signal.





Answer: E

In a positive-feedback system where hormone A alters the amount of protein X

In a positive-feedback system where hormone A alters the amount of protein X 

A) an increase in A always produces an increase in X.
B) an increase in X always produces a decrease in A.
C) a decrease in A always produces an increase in X.
D) a decrease in X always causes a decrease in A.
E) it is impossible to predict how A and X affect each other.







Answer: A

All hormones

All hormones 

A) are produced by endocrine glands.
B) are lipid-soluble molecules.
C) are carried to target cells in the blood.
D) are protein molecules.
E) elicit the same biological response from all of their target cells.







Answer: C

African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation?

African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? 

A) Urea takes less energy to synthesize than ammonia.
B) Small stagnant pools do not provide enough water to dilute the toxic ammonia.
C) The highly toxic urea makes the pool uninhabitable to potential competitors.
D) Urea forms an insoluble precipitate.
E) Urea makes lungfish tissue hypoosmotic to the pool.






Answer: B

Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?

Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species? 

A) a river otter
B) a mouse species living in a tropical rain forest
C) a mouse species living in a temperate broadleaf forest
D) a mouse species living in a desert
E) a beaver




Answer: D

The high osmolarity of the renal medulla is maintained by all of the following except

The high osmolarity of the renal medulla is maintained by all of the following except 

A) diffusion of salt from the thin segment of the ascending limb of the loop of Henle.
B) active transport of salt from the upper region of the ascending limb.
C) the spatial arrangement of juxtamedullary nephrons.
D) diffusion of urea from the collecting duct.
E) diffusion of salt from the descending limb of the loop of Henle.





Answer: E

Which of the following animals generally has the lowest volume of urine production?

Which of the following animals generally has the lowest volume of urine production? 

A) a vampire bat
B) a salmon in fresh water
C) a marine bony fish
D) a freshwater bony fish
E) a shark inhabiting freshwater Lake Nicaragua






Answer: C

Which process in the nephron is least selective?

Which process in the nephron is least selective? 

A) filtration
B) reabsorption
C) active transport
D) secretion
E) salt pumping by the loop of Henle





Answer: A

Unlike an earthworm's metanephridia, a mammalian nephron

Unlike an earthworm's metanephridia, a mammalian nephron 

A) is intimately associated with a capillary network.
B) forms urine by changing fluid composition inside a tubule.
C) functions in both osmoregulation and excretion.
D) receives filtrate from blood instead of coelomic fluid.
E) has a transport epithelium.





Answer: D

In a laboratory experiment with three groups of students, one group drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution, all during the same time period. Their urine production is monitored for several hours. Which groups are expected to have the greatest and least amounts of urine, respectively?

In a laboratory experiment with three groups of students, one group drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution, all during the same time period. Their urine production is monitored for several hours. Which groups are expected to have the greatest and least amounts of urine, respectively? 

A) Beer drinkers have the most; salt solution drinkers have the least.
B) Salt solution drinkers have the most; water drinkers have the least.
C) Water drinkers have the most; beer drinkers have the least.
D) Beer drinkers have the most; water drinkers have the least.
E) There will be no significant difference between these groups.






Answer: A

ADH and RAAS work together in maintaining osmoregulatory homeostasis through which of the following ways?

ADH and RAAS work together in maintaining osmoregulatory homeostasis through which of the following ways? 

A) ADH regulates the osmolarity of the blood and RAAS regulates the volume of the blood.

B) ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and RAAS maintains the osmolarity of the blood by stimulating Na+ reabsorption.

C) ADH and RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS causes increased excretion of water when it is in excess in body fluids.

D) both stimulate the adrenal gland to secrete aldosterone, which increases both blood volume and pressure via its receptors in the urinary bladder.

E) by combining at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place.




Answer: B

Antidiuretic hormone (ADH) functions at the cellular level by

Antidiuretic hormone (ADH) functions at the cellular level by 

A) stimulating the reabsorption of glucose through channel proteins.
B) triggering the synthesis of an enzyme that makes the phospholipid bilayer more permeable to water.
C) causing membranes to include more phospholipids that have unsaturated fatty acids.
D) causing an increase in the number of aquaporin molecules of collecting duct cells.
E) decreasing the speed at which filtrate flows through the nephron, leading to increased reabsorption of water.






Answer: D

Osmoregulatory adjustment via the renin-angiotensin-aldosterone system can be triggered by

Osmoregulatory adjustment via the renin-angiotensin-aldosterone system can be triggered by 

A) sleeping for one hour.
B) severe sweating on a hot day.
C) eating a bag of potato chips.
D) eating a pizza with olives and pepperoni.
E) drinking several glasses of water.




Answer: B

After drinking alcoholic beverages, increased urine excretion is the result of

After drinking alcoholic beverages, increased urine excretion is the result of 

A) increased aldosterone production.
B) increased blood pressure.
C) inhibited secretion of antidiuretic hormone (ADH).
D) increased reabsorption of water in the proximal tubule.
E) the osmoregulator cells of the brain increasing their activity.






Answer: C

After blood flow is artificially reduced at one kidney, you would expect that kidney to secrete more of the hormone known as

After blood flow is artificially reduced at one kidney, you would expect that kidney to secrete more of the hormone known as 

A) erythropoietin.
B) angiotensinogen.
C) renin.
D) antidiuretic hormone.
E) atrial natriuretic peptide.





Answer: C

Increased ADH secretion is likely after

Increased ADH secretion is likely after 

A) drinking lots of pure water.
B) sweating-induced dehydration increases plasma osmolarity.
C) ingestion of ethanol (drinking alcoholic drinks).
D) eating a small sugary snack.
E) blood pressure is abnormally high.




Answer: B

When stimulated by aldosterone, the reabsorption of Na+ is increased along

When stimulated by aldosterone, the reabsorption of Na+ is increased along 

A) the loop of Henle.
B) the collecting duct.
C) Bowman's capsule.
D) the proximal tubule.
E) the distal tubule.





Answer: E

Trauma to the human kidney could result in a urinary filtrate containing an abnormally high level of

Trauma to the human kidney could result in a urinary filtrate containing an abnormally high level of 

A) fatty acids.
B) glucose.
C) salts.
D) erythrocytes.
E) vitamins.





Answer: D

The typical osmolarity of human blood is

The typical osmolarity of human blood is 

A) 30 mosm/L.
B) 100 mosm/L.
C) 200 mosm/L.
D) 300 mosm/L.
E) 500 mosm/L.





Answer: D