Deck 5: Principals of Endocrinology; The Central Endocrine Glands

Question 1

Which statement concerning hormones is correct?

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) All act by activating adenylate cyclase, which transforms ATP into cyclic AMP.

Answer 1

B

Question 2

What is the specificity of hormones due to?

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

Answer 2

D

Question 3

Which statement concerning neurosecretory neurons is correct?

A) They release neurotransmitters.
B) They release hormones.
C) They are unable to conduct action potentials, unlike ordinary neurons.
D) They release neurotransmitters and are unable to conduct action potentials, unlike ordinary neurons.

Answer 3

B

Question 4

Which of the following is NOT controlled at least in part by hormones?

A) homeostasis
B) organic metabolism
C) rapid interactions with the external environment
D) H2O and electrolyte balance

Question 5

Which statement is correct about 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 6

Which class of hormones is NOT stored in the secretory cell after being synthesized?

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

Question 7

Which hormone is NOT a tropic hormone?

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

Question 8

Which statement regarding endocrine glands is INCORRECT?

A) They produce hormones.
B) They secrete their products into the blood.
C) They comprise epithelial tissue.
D) They are all controlled by the nervous system.

Question 9

Which statement concerning tropic hormones is correct?

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) All have non-tropic functions, too.

Question 10

Which statement concerning peptide hormones is INCORRECT?

A) Peptides are synthesized by the endoplasmic reticulum-Golgi complex system.
B) Peptides circulate largely bound to plasma proteins.
C) Peptides bind to surface receptors of their target cells.
D) Peptides exert their effect largely by means of second-messenger systems.

Question 11

Which statement concerning hormones is correct?

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 the target cells in order to exert their effects.
D) They are produced in a gland and act on the target cells in different tissues.

Question 12

What accomplishes the transport of lipid-soluble hormones in the blood?

A) loose binding with iodine
B) specific binding to plasma proteins
C) HDLs
D) glycolipids

Question 13

Which statement concerning hormones is INCORRECT?

A) A single endocrine gland may produce multiple hormones.
B) A single target cell may be influenced by more than one hormone.
C) A single hormone can influence only one type of target cell.
D) An endocrine organ may exert nonendocrine functions in addition to secreting hormones.

Question 14

Which class of hormones is released by exocytosis upon appropriate stimulation?

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

Question 15

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

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

Question 16

Which statement concerning amines is correct?

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 adrenal medulla.
D) They are derived from tyrosine.

Question 17

Hormones are classified into which three types?

A) amines, peptides, and steroids
B) amines, steroids, and phospholipids
C) amines, phospholipids, and steroids
D) amines, free fatty acids, and peptides

Question 18

Which statement regarding tropic hormones is INCORRECT?

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

Question 19

Which statement about peptide hormones is INCORRECT?

A) They include adrenal cortex hormones.
B) Insulin is an example.
C) They are stored within secretory granules.
D) They are secreted from endocrine glands.

Question 20

What is NOT a function of the endocrine system?

A) maintenance of blood sugar levels
B) regulation of metabolic activity and H2O and electrolyte balance
C) promotion of growth and development
D) transduction of external stimuli

Question 21

What 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

Question 22

What does permissiveness of hormones refer to?

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, even though the first hormone itself does not directly elicit the response.
D) Through numerous neuroendocrine relationships the nervous system permits the endocrine system to function.

Question 23

What occurs 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 24

Which statement concerning lipophilic hormones is correct?

A) They include catecholamines.
B) They bind with receptors located inside their target cells.
C) They activate second-messenger systems within their target cells.
D) They circulate as free hormones.

Question 25

Which molecular precursor is the derivative of estrogens,testosterone,cortisol,and aldosterone?

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

Question 26

Which statement concerning control of hormone secretion is NOT correct?

A) Normally the effective plasma concentration of a hormone is regulated by appropriate adjustments in the rate of its secretion.
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 27

Which statement about TSH is correct?

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 28

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

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

Question 29

Which characteristic is NOT shared by both lipophilic and hydrophilic hormones?

A) amplification of hormone actions in the target cell
B) transport via plasma proteins
C) synergistic actions
D) antagonistic actions

Question 30

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

A) peptides
B) steroids
C) thyroid hormone
D) all lipophilic hormones

Question 31

Which statement concerning diurnal rhythms is correct?

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 32

Which hormone type does NOT require membrane receptors to invoke cell responses?

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

Question 33

With regards to circadian rhythms,which statement is true?

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 34

What happens in the second messenger?

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, catalyzing cAMP formation.

Question 35

Which statement about the post-receptor events of hydrophilic hormones is INCORRECT?

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) Steroid hormones use this kind of hormone mechanism.

Question 36

Which situation 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 37

Which statement concerning steroids is correct?

A) They are hydrophilic
B) They are derived from cholesterol.
C) They initiate the synthesis of second messenger system within their target cells.
D) Epinephrine is an example.

Question 38

What is the most common second messenger used by hydrophilic hormones?

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

Question 39

What is NOT associated with the post-receptor events of hydrophilic hormones?

A) cyclic AMP
B) protein kinase
C) adenylate cyclase
D) chromatin

Question 40

What must lipophilic hormones interact with prior to gene activation?

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

Question 41

When will synergism occur?

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, even though the first hormone does not directly elicit the response
D) when one hormone increases the number of target-tissue receptors for another hormone

Question 42

Which structure secretes insulin and glucagon?

A) posterior pituitary
B) liver
C) pancreas
D) stomach

Question 43

Which gland produces melatonin?

A) anterior pituitary
B) posterior pituitary
C) pineal
D) hypothalamus

Question 44

How is hormone secretion from the anterior pituitary gland controlled?

A) byneuronal 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 hypothalamus

Question 45

Which endocrine hypofunction disorder does NOT result from too little hormone activity?

A) lack of target cell receptors
B) hyposecretion
C) reduced plasma protein binding
D) increased removal from blood

Question 46

Which statement concerning an antioxidant melatonin is correct?

A) It accelerates metabolism.
B) It defends against free radicals.
C) It lowers the concentration of blood sugar.
D) It serves as a secondary messenger.

Question 47

Which of the following is a neurohormone?

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

Question 48

Which hormone is released from the hypothalamus?

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

Question 49

A portal system exists between which glands?

A) adrenal cortex and adrenal medulla
B) hypothalamus and anterior pituitary
C) hypothalamus and posterior pituitary
D) large intestine and small intestine

Question 50

Which statement concerning the posterior pituitary is correct?

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 51

Which statement concerning melanocyte-stimulating hormones is correct?

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 52

Which is an INCORRECT association?

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

Question 53

Which may be included in melatonin's actions?

A) regulation of circadian rhythms
B) having permissive action with glucorticoids
C) induction of calcium reabsorption
D) stimulation of melanin pigment production

Question 54

What has a direct anatomical connection to the hypothalamus?

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

Question 55

Which structure is neuroendocrine in nature?

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

Question 56

Which hormone secreted by the anterior pituitary is nontropic?

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

Question 57

What can too little activity of a particular hormone arise from?

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

Question 58

Which statement concerning the anterior pituitary is correct?

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 59

Which statement concerning the posterior pituitary is correct?

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

Question 60

Which statement concerning melanocyte-stimulating hormones is correct?

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 61

What 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 62

Which statement concerning growth hormone is correct?

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

Question 63

Which statement concerning growth hormone is correct?

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 s the only factor responsible for governing the growth of an individual.

Question 64

The growth hormone signals activity of which of the following in a long bone to influence its length?

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

Question 65

What 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 a tropic hormone.

Question 66

Which statement concerning the hypothalamo-hypophyseal portal system is correct?

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 67

What is NOT a function of growth hormone?

A) It increases uptake of amino acids by cells.
B) It stimulates the synthesis of somatomedins.
C) It enhances glucose uptake by muscle cells.
D) It stimulates cell division.

Question 68

Which of the following is correct for hormones produced in the anterior pituitary?

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

Question 69

Hypophysiotropic hormones from the hypothalamus assist which action?

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

Question 70

What is stimulated by LH?

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

Question 71

Which statement concerning the hypothalamo-hypophyseal portal system is correct?

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 72

Which of the following represent 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 73

Which statement concerning growth hormone is correct?

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 74

Which statement concerning hypophysiotropic hormones is correct?

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

Question 75

What 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 76

Which statement concerning growth hormone is correct?

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

Question 77

Which hormone is regulated by the anterior pituitary?

A) parathyroid hormone
B) Cortisol
C) Aldosterone
D) Insulin

Question 78

Which statement regarding vasopressin is INCORRECT?

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 79

Which pituitary hormone has NO role in reproductive physiology?

A) follicle-stimulating hormone
B) luteinizing hormone
C) Oxytocin
D) Vasopressin

Question 80

Which hormone signals the kidneys to control water balance?

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