Question 1

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.

Accepted Answer

The fact that prolactin has multiple functions across different species suggests that it is evolutionarily conserved and has been important throughout the history of vertebrates.

Answer: B
 The varied effects of prolactin suggest that it likely interacts with a unique mechanism or set of mechanisms to elicit its effects.

Therefore, the best choice is either C or B.

Question 2

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.

Accepted Answer

ADH (antidiuretic hormone) acts on its target cells in the kidney to reduce water loss by stimulating the insertion of aquaporins (water channels) in the plasma membrane of the kidney tubules. This increases water reabsorption and reduces urine output, helping to prevent dehydration.

Question 3

Oxytocin and antidiuretic hormone are synthesized in the
A) hypothalamus.
B) adenohypophysis.
C) anterior pituitary.
D) adrenal cortex.
E) posterior pituitary.

Accepted Answer

Oxytocin and antidiuretic hormone (ADH) are synthesized in the hypothalamus and then transported to and released from the posterior pituitary.

Question 4

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.

Accepted Answer

The posterior pituitary gland and the adrenal medulla are both endocrine structures derived from nervous tissue. The posterior pituitary gland is derived from neural tissue in the hypothalamus and releases hormones such as oxytocin and vasopressin. The adrenal medulla, which is part of the adrenal gland, is also derived from neural tissue and produces hormones such as adrenaline and noradrenaline.

Question 5

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.

Accepted Answer

Juvenile hormone is responsible for regulating insect development and preventing them from maturing into adults. Synthetic agonists of juvenile hormone can disrupt this process and prevent the insects from reproducing.

Question 6

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

Accepted Answer

Prostaglandin F and nitric oxide have opposite effects on smooth muscle contraction, with prostaglandin F causing contraction and nitric oxide causing relaxation. Therefore, they would not be expected to be active at the same time and place. The other pairs listed are not necessarily mutually exclusive and could be active at the same time and place.

Question 7

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.

Accepted Answer

Prolactin promotes milk synthesis while oxytocin promotes milk release in lactating mammals.

Question 8

Iodine is added to table salt to help prevent deficiencies of an essential mineral needed for the proper function of the
A) parathyroid glands.
B) adrenal glands.
C) thyroid glands.
D) the endocrine pancreas.
E) the exocrine pancreas.

Accepted Answer

Iodine is an essential mineral needed by the thyroid gland to produce hormones that regulate metabolism. Deficiencies in iodine can lead to insufficient thyroid hormone production and potentially serious health consequences such as goiter and hypothyroidism. Adding iodine to table salt is a way to ensure that people consume enough of this mineral and prevent deficiencies.

Question 9

Fight-or-flight reactions include activation of
A) the parathyroid glands, leading to increased metabolic rate.
B) the thyroid gland, leading to an increase in the blood calcium concentration.
C) the anterior pituitary gland, leading to cessation of gonadal function.
D) the adrenal medulla, leading to increased secretion of epinephrine.
E) the pancreas, leading to a reduction in the blood sugar concentration.

Accepted Answer

The adrenal medulla is responsible for producing and releasing epinephrine (also known as adrenaline), which is a key hormone involved in the fight-or-flight response. This hormone triggers a number of physical responses, including increased heart rate, increased blood pressure, and increased respiration rate to help prepare the body for intense physical activity.

Question 10

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.

Accepted Answer

Neurosecretory cells in the hypothalamus produce hormones that regulate the release of hormones from the pituitary gland, which is an important part of the endocrine system. This demonstrates the interrelationship between the nervous and endocrine systems.

Answer: B
 Steroid-producing cells in the adrenal cortex are stimulated to produce hormones by a cascade of signals that involve the hypothalamus and pituitary gland, which are part of the nervous system. This again highlights the connection between the two systems.

The other choices are not as directly related to the interplay between the endocrine and nervous systems.

Question 11

A tropic hormone from the anterior pituitary gland regulates the secretion of
A) parathyroid hormone.
B) calcitonin.
C) epinephrine.
D) thyroxine.
E) glucagon.

Accepted Answer

A tropic hormone from the anterior pituitary gland regulates the secretion of thyroxine. This hormone is called thyroid-stimulating hormone (TSH) and stimulates the thyroid gland to produce and release thyroxine (T4) and triiodothyronine (T3). These hormones are important in regulating metabolism, growth, and development.

Question 12

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.

Accepted Answer

Oxytocin is involved in a positive feedback loop during labor and delivery. As uterine contractions increase, oxytocin is released, which further enhances uterine contractions. This positive feedback loop continues until the baby is delivered.

Question 13

One reason a person might be severely overweight is due to
A) an undersecretion of thyroxine.
B) a defect in hormone release from the posterior pituitary.
C) a lower than normal level of insulin-like growth factors.
D) hyposecretion of oxytocin.
E) a higher than normal level of melatonin.

Accepted Answer

An undersecretion of thyroxine (thyroid hormone) can lead to a slower metabolic rate, which can cause weight gain and difficulty losing weight.

Question 14

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.

Accepted Answer

The hypothalamus includes neurosecretory cells that terminate in the posterior pituitary, which releases hormones that regulate various physiological functions in the body. While the hypothalamus does have receptors for certain hormones, it is primarily involved in neuronal transmission and regulation of the endocrine system through its release of hormones that stimulate or inhibit pituitary function. The hypothalamus does not, however, directly secrete tropic hormones that act on the gonads.

Question 15

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.

Accepted Answer

Glucagon is the hormone responsible for promoting the breakdown of glycogen and the conversion of other molecules, such as fats and amino acids, into glucose for energy production during short-term starvation. It opposes the action of insulin, which promotes fuel storage and anabolism, and helps to maintain blood glucose homeostasis. The other hormones listed are not directly involved in this process.

Question 16

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.

Accepted Answer

The hypothalamus produces and releases peptide hormones, such as gonadotropin-releasing hormone (GnRH), that travel to the anterior pituitary gland and stimulate the release of specific tropic hormones that control various endocrine glands throughout the body.

Answer: D
 The hypothalamus also uses neurotransmitters, such as dopamine and serotonin, to regulate the secretion of certain anterior pituitary hormones.

Therefore, the best answer is A and D.

Question 17

The endocrine glands include the
A) parathyroid glands.
B) salivary glands.
C) sweat glands.
D) sebaceous glands.
E) gallbladder.

Accepted Answer

The parathyroid glands are a type of endocrine gland that are responsible for regulating the levels of calcium and phosphate in the body. They are located near the thyroid gland in the neck. None of the other choices listed are endocrine glands.

Question 18

Which endocrine disorder is correctly matched with the malfunctioning gland?
A) diabetes insipidus and the posterior pituitary gland
B) giantism and the posterior pituitary gland
C) goiter and the adrenal medulla
D) diabetes mellitus and the parathyroid glands
E) dwarfism and the adrenal cortex

Accepted Answer

Diabetes insipidus is a disorder caused by the insufficient production of antidiuretic hormone (ADH) in the posterior pituitary gland, leading to excessive urine production and thirst.

Answer: B
 Giantism is a disorder caused by the overproduction of growth hormone in the anterior pituitary gland, leading to excessive growth and height.

Answer: C
 Goiter is a disorder caused by the enlargement of the thyroid gland due to iodine deficiency or other factors, but it does not involve the adrenal medulla.

Answer: D
 Diabetes mellitus is a disorder caused by the insufficient production or utilization of insulin in the pancreas, but it does not involve the parathyroid glands.

Answer: E
 Dwarfism can be caused by various factors, such as genetic mutations or growth hormone deficiency, but it does not involve the adrenal cortex specifically.

Question 19

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.

Accepted Answer

Portal blood vessels connect the hypothalamus and anterior pituitary gland.

Question 20

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.

Accepted Answer

MSH (melanocyte-stimulating hormone) is a product of the anterior pituitary gland and causes color changes (melanin production) in its target cells, the melanocytes. FSH (follicle-stimulating hormone), LH (luteinizing hormone), TSH (thyroid-stimulating hormone), and ACTH (adrenocorticotropic hormone) do not cause color changes in target cells.

Quiz 45: Hormones and the Endocrine System

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

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

Oxytocin and antidiuretic hormone are synthesized in the

Endocrine structures derived from nervous tissue include the

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

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

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

Iodine is added to table salt to help prevent deficiencies of an essential mineral needed for the proper function of the

Fight-or-flight reactions include activation of

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

A tropic hormone from the anterior pituitary gland regulates the secretion of

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

One reason a person might be severely overweight is due to

The hypothalamus

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

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

The endocrine glands include the

Which endocrine disorder is correctly matched with the malfunctioning gland?

Portal blood vessels connect two capillary beds found in the

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