Deck 5: Principles of Endocrinology: The Central Endocrine Glands

Question 1

Which of the following can influence the effective plasma concentration of a hormone

A)the hormone's rate of binding to receptors on target tissues
B)the hormone's extent of binding to plasma proteins
C)the hormone's rate of metabolic activity
D)the hormone's rate of secretion

Answer 1

D

Question 2

Which of these statements refers to the permissiveness of hormones

A)Hormones permit cellular processes to occur.
B)Hormones permit their target organs to function at the optimal rate.
C)In some instances, an adequate amount of one hormone must be present for the full exertion of another hormone's effect.
D)Through numerous neuroendocrine relationships, the nervous system allows the endocrine system to function.

Answer 2

C

Question 3

Which of these statements describes tropic hormones

A)They are produced by the posterior pituitary.
B)They are secreted only by the hypothalamus.
C)They primarily regulate hormone secretion by certain other endocrine glands.
D)They all have non-tropic functions too.

Answer 3

C

Question 4

Which of these statements describes tropic hormones

A)They may stimulate the secretion of other hormones.
B)They are secreted only by the hypothalamus.
C)They are all produced in the posterior pituitary gland.
D)Primary hyposecretion occurs when an endocrine gland isn't receiving enough of its tropic hormone.

Question 5

Which of the following can occur in the process of negative feedback

A)TSH inhibits thyroid hormone secretion by the thyroid gland.
B)Thyroid hormone inhibits TSH secretion by the anterior pituitary.
C)Thyroid hormone directly inhibits further thyroid hormone secretion by the thyroid gland.
D)TRH inhibits TSH secretion by the anterior pituitary.

Question 6

Which of these statements applies to circadian rhythms

A)The hypothalamus's supraoptic nucleus maintains them.
B)Melanin is responsible for generating them.
C)They are brought about by fluctuating levels of clock proteins.
D)The pituitary gland maintains them.

Question 7

Which of these hormones is NOT a tropic hormone

A)ACTH
B)ADH
C)ICSH
D)LH

Question 8

Which of these situations represents negative feedback

A)Hormone A stimulates hormone B; hormone B inhibits hormone C.
B)Hormone A inhibits hormone B; hormone B inhibits hormone A.
C)Hormone A stimulates hormone B; hormone B inhibits hormone A.
D)Hormone A inhibits hormone B; hormone B inhibits hormone C.

Question 9

Which of these statements describes hormones

A)All are regulated by the hypothalamus.
B)They are secreted by endocrine glands through ducts into the blood.
C)They must combine with specific receptors on their target cells in order to exert their effects.
D)They are produced in a gland and act on target cells in different tissues.

Question 10

Under which of these circumstances is synergism occurring

A)when one hormone induces the loss of another hormone's receptors
B)when the actions of several hormones are complementary, and their combined effect is greater than the sum of their separate effects
C)when one hormone must be present in adequate amounts for the full exertion of another hormone's effect
D)when one hormone increases the number of target-tissue receptors for another hormone

Question 11

Which of these statements describes neurosecretory neurons

A)They release neurotransmitters.
B)They release hormones.
C)They release chemicals.
D)They are able to conduct action potentials.

Question 12

Which of these statements describes hormones

A)They are released from exocrine glands.
B)They interact with receptors at target-cell sites.
C)They are synthesized in the lymph nodes.
D)They interact with receptors in the blood.

Question 13

Which of these activities happens in a short-loop, negative-feedback, control system

A)The anterior pituitary hormone feeds back to the hypothalamus, suppressing releasing hormone.
B)The target gland's hormone feeds back to the anterior pituitary, suppressing the tropic hormone.
C)The target gland's hormone does not feed back to any other gland.
D)The anterior pituitary hormone feeds back to the posterior pituitary gland, stimulating the inhibiting hormone.

Question 14

Which of these statements describes hormones

A)They are all of similar chemical composition.
B)They combine with specific receptors on the target cell's surface or inside the target cell.
C)They are secreted at a constant rate.
D)They all act by activating adenylate cyclase, which transforms ATP into cyclic AMP.

Question 15

Which of these statements describes diurnal rhythms

A)They are inherent cyclical peaks and ebbs of hormone secretion that are a function of time and are entrained to the 24-hour light-dark cycle.
B)They are important in maintaining hormone levels at a relatively constant set point, no matter the time of day.
C)They occur only with cortisol secretion.
D)They occur only with growth hormone secretion.

Question 16

Which of these circumstances is the cause of too little activity of a particular hormone

A)an abnormality within the endocrine gland that produces this hormone
B)overactivity of this hormone's tropic hormone
C)overstimulation by the hypothalamus
D)overstimulation of the pituitary gland

Question 17

Why do hormones have specificity

A)due to specialized hormone secretion
B)due to molecular rearrangement at the site of action
C)due to specific binding of hormones to plasma proteins
D)due to specialization of target-cell receptors

Question 18

Which of these statements does NOT describe hormones

A)Many of them may be produced by a single endocrine gland.
B)More than one type may influence a single target cell.
C)Each type can influence only one type of target cell.
D)They may be secreted by an endocrine organ that may also exert nonendocrine functions.

Question 19

Which of these statements describes hormones secreted by endocrine glands

A)They are secreted into the ducts.
B)They are all controlled by the nervous system.
C)They all can pass through the plasma membrane.
D)They regulate cellular and organ function at a distance.

Question 20

Which of these statements describes control of hormone secretion

A)Normally, the effective plasma concentration of a hormone is regulated by the rate of its synthesis.
B)In order to maintain homeostasis, the rate of hormone secretion remains constant.
C)All hormones are regulated with negative-feedback controls.
D)Neuroendocrine reflexes produce a sudden increase in hormone secretion in response to a specific, usually external, stimulus.

Question 21

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.

Question 22

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.

Question 23

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

Question 24

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

Question 25

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.

Question 26

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

Question 27

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

A)peptides
B)catecholamines
C)steroids
D)thyroid hormones

Question 28

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

A)DHEA
B)cholesterol
C)UDP-glucose
D)epinephrine

Question 29

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.

Question 30

Which class of hormones is released by exocytosis upon appropriate stimulation

A)peptides
B)thyroxin
C)steroids
D)insulins

Question 31

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

Question 32

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

Question 33

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.

Question 34

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.

Question 35

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

A)catecholamines
B)proteins
C)steroids
D)thyroid hormones

Question 36

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

A)membrane receptors
B)cAMP
C)hormone response elements
D)G proteins

Question 37

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

A)catecholamines
B)steroids
C)peptides
D)parathyroid hormones

Question 38

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.

Question 39

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.

Question 40

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

A)calcium
B)cyclic AMP
C)chromatin
D)messenger RNA

Question 41

A portal system exists between which of the following glands

A)adrenal cortex and adrenal medulla
B)thyroid gland and parathyroid gland
C)hypothalamus and posterior pituitary
D)hypothalamus and anterior pituitary

Question 42

Which of these statements applies to TSH

A)A buildup of the thyroid hormone stimulates its production by negative feedback.
B)It is secreted by the thyroid gland.
C)It is stored in the posterior pituitary.
D)It stimulates the thyroid gland.

Question 43

Which of these structures is neuroendocrine in nature

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

Question 44

Which statement does NOT describe vasopressin

A)It is produced in the hypothalamus.
B)It stimulates uterine smooth muscle contraction.
C)It increases kidney reabsorption of water.
D)It is a potent arteriolar vasoconstrictor.

Question 45

Which of these statements describes melanocyte-stimulating hormones

A)They are secreted by the hypothalamus.
B)They are known to cause skin darkening in certain lower vertebrates.
C)They are believed to be responsible for the tanning phenomenon in humans.
D)They are responsible for circadian rhythm.

Question 46

Which of these structures has a direct anatomical connection to the hypothalamus

A)adrenal gland
B)posterior lobe of the pituitary
C)thyroid gland
D)parathyroid gland

Question 47

Which of these statements describes the hypothalamic-hypophyseal portal system

A)It carries anterior pituitary hormones from the anterior pituitary gland to the hypothalamus to regulate the release of hypophysiotropic hormones.
B)It diverts blood directly to the pituitary, completely bypassing the hypothalamus.
C)It carries hypophysiotropic hormones from the hypothalamus to the anterior pituitary to regulate anterior pituitary hormone secretion.
D)It carries the anterior pituitary hormones into the general systemic circulation.

Question 48

Which of these statements applies to the posterior pituitary

A)It secretes ADH.
B)It stores anterior pituitary hormones.
C)It stores ACTH and LH.
D)It secretes vasopressin and oxytocin into the hypothalamic-hypophyseal portal system.

Question 49

Which of these statements applies to melanocyte-stimulating hormones

A)They are responsible for the deposition of melanin in the skin during the process of tanning.
B)They are not present in significant amounts in adult humans.
C)They are present in varying amounts in races of different skin colour.
D)They are important for colour adaptations associated with camouflage in certain lower vertebrates.

Question 50

How is hormone secretion from the anterior pituitary gland controlled

A)by neuronal cell bodies from the hypothalamus
B)directly, by neural innervation of anterior pituitary cells
C)by negative-feedback action of target-tissue hormones
D)only by inhibiting hormones from the hypothalamus

Question 51

Which of these statements describes hypophysiotropic hormones from the hypothalamus

A)They control the release of oxytocin and vasopressin from the posterior pituitary.
B)They travel via neuron axons from the hypothalamus to the anterior pituitary.
C)They are carried in the hypothalamic-hypophyseal portal system.
D)They are released upon positive-feedback stimulation via the anterior pituitary tropic hormones.

Question 52

Which of these hormones is a neurohormone

A)vasopressin
B)thyroid hormone
C)growth hormone
D)cortisol

Question 53

Which of these statements describes hypophysiotropic hormones

A)Each one influences only one anterior pituitary hormone.
B)All of them stimulate the release of anterior pituitary hormones.
C)They are also produced outside the hypothalamus, where they serve different functions.
D)They are secreted into the general circulation.

Question 54

Which of these statements describes the anterior pituitary

A)It is also known as the neurohypophysis.
B)It is composed primarily of nervous tissue.
C)It primarily secretes tropic hormones.
D)It secretes vasopressin

Question 55

Which of the following is NOT a correct association

A)adrenal medulla and vasopressin
B)anterior pituitary and adenohypophysis
C)epinephrine and catecholamine
D)insulin and polypeptide

Question 56

Which of these events is stimulated by LH

A)destruction of the cells of Leydig
B)enlargement of the follicles
C)development of the hypothalamus
D)formation of the corpus luteum

Question 57

Which one of these hormones is released from the hypothalamus

A)CRH
B)TSH
C)FS
D)LH

Question 58

Which of the following is NOT a characteristic of the hormone oxytocin

A)It stimulates uterine contractions.
B)It promotes milk ejection from mammary gland ducts.
C)It influences bonding behaviour between mother and baby.
D)It is secreted by the anterior pituitary gland.

Question 59

Which one of these hormones secreted by the anterior pituitary is non-tropic

A)TSH
B)prolactin
C)LH
D)ACTH

Question 60

Which of these statements applies to the posterior pituitary

A)It is composed of vascular tissue.
B)It stores anterior pituitary hormones, which are released into the blood upon hypothalamic stimulation.
C)It synthesizes and secretes vasopressin and oxytocin.
D)It stimulates the adrenal gland.

Question 61

How does growth hormone exert its effects on growth

A)by stimulating production of somatomedins
B)by directly invoking gene activity
C)by elevating blood glucose levels
D)by increasing fat metabolism

Question 62

Which of the following is NOT an effect of GH

A)increased fat breakdown
B)increased bone growth
C)decreased glucose entry into muscle cells
D)decreased protein synthesis

Question 63

Which of these hormones is regulated by the anterior pituitary

A)parathyroid hormone
B)cortisol
C)aldosterone
D)insulin

Question 64

Which of these statements applies to the hypothalamic-hypophyseal portal system

A)It carries vasopressin and oxytocin from the hypothalamus to the posterior pituitary for storage.
B)It carries hypophysiotropic hormones from the hypothalamus to the posterior pituitary to control the release of posterior pituitary hormones.
C)It carries hypophysiotropic hormones from the hypothalamus to the anterior pituitary to control the release of anterior pituitary hormones.
D)It carries vasopressin and oxytocin from the hypothalamus to the anterior pituitary to control the release of anterior pituitary hormones.

Question 65

Which one of these hormones signals the kidneys to control water balance

A)vasopressin
B)ACTH
C)TRH
D)somatostatin

Question 66

Which of these statements applies to growth hormone

A)It directly stimulates bone growth.
B)It promotes low blood glucose level.
C)It promotes closure of the epiphyseal plate.
D)It affects bones via somatomedin release.

Question 67

Which of these circumstances results in somatomedins being released from the liver

A)increased plasma growth hormone levels
B)increased plasma somatostatin levels
C)decreased plasma growth hormone levels
D)decreased plasma somatostatin levels

Question 68

Which of these pituitary hormones is NOT involved in reproductive physiology

A)follicle-stimulating hormone
B)luteinizing hormone
C)oxytocin
D)vasopressin

Question 69

Which of these statements describes osteoblasts

A)They secrete the organic matrix components of bone.
B)They promote osteoclast activity.
C)They dissolve bone tissue.
D)They are cartilage cells.

Question 70

Which of these statements applies to growth hormone

A)It closes the epiphyseal plate of long bones.
B)It promotes hypertrophy and hyperplasia.
C)Its secretion is stimulated by an increased blood glucose level.
D)It is the only factor responsible for governing the growth of an individual.

Question 71

Which of these factors does NOT increase growth hormone secretion

A)deep sleep
B)exercise
C)low blood amino acid level
D)stress

Question 72

Which of these statements applies to growth hormone

A)It increases the uptake of amino acids by cells.
B)It promotes lipid synthesis.
C)It works with insulin to lower blood sugar.
D)It is secreted by the hypothalamus.

Question 73

Which statement does NOT describe IGF

A)The concentration of IGF-I in blood plasma normally mimics the rate of secretion of GH.
B)Fasting decreases IGF-I levels even though it increases GH secretion.
C)IGF-II, which is important during fetal development, is also influenced by GH.
D)Glycogen synthesis is decreased by GH through IGF.

Question 74

Growth hormone signals which of the following parts in a long bone to influence its length

A)articular cartilage
B)endosteum
C)epiphyseal plate
D)medullary cavity

Question 75

Which of these statements represents long-loop, negative feedback in the CRH-ACTH-cortisol system

A)Cortisol inhibits CRH secretion.
B)CRH inhibits ACTH secretion.
C)ACTH inhibits CRH secretion.
D)ACTH inhibits cortisol secretion.

Question 76

A deficiency in which of these hormones may result in dwarfism

A)growth hormone-inhibiting hormone
B)thyroid-stimulating hormone
C)thyroid hormone
D)GH

Question 77

Which of these statements describes growth hormone

A)Levels in the blood are directly correlated with the rate of growth throughout life.
B)It stimulates the secretion of somatomedins.
C)It stimulates osteoclast activity.
D)Excessive levels in adults will cause the disease called gigantism.

Question 78

Which of these statements refers to bone cells

A)Osteoclasts are cells that make new ones.
B)Chondrocytes are some that are affected by prolactin-inhibiting hormone.
C)Osteoclasts are the types that dissolve bone.
D)Osteoblasts are mature, nongrowing bone.

Question 79

Which of the following is NOT a function of growth hormone

A)to increase the uptake of amino acids by cells
B)to stimulate the synthesis of somatomedins
C)to enhance glucose uptake by muscle cells
D)to stimulate cell division

Question 80

Which of these statements describes hormones produced in the anterior pituitary

A)They are synthesized by the hypothalamus.
B)They may be only non-tropic.
C)They are secreted into the blood.
D)They are secreted into ducts.