Deck 18: A--Principles of Endocrinology: the Central Endocrine Glands

Question 1

Which class of hormones are polar and, accordingly, hydrophilic?

A) peptides
B) catecholamines
C) Steroids
D) peptides and catecholamines
E) none of these

Answer 1

D

Question 2

Which of the following 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
E) helping the body cope with stressful situations

Answer 2

D

Question 3

Which class(es) of hormones is not stored in the secretory cell after being synthesized?

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

Answer 3

C

Question 4

Tropic hormones

A) are produced by the posterior pituitary
B) are secreted only by the hypothalamus
C) primarily regulate hormone secretion by certain other endocrine glands
D) all have non-tropic functions too
E) are the hormones that stimulate athletes to win trophies

Question 5

Select the hormone that is not a tropic hormone.

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

Question 6

Hormones are classified into three types:

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

Question 7

Which of the classes of hormones are synthesized by the endoplasmic reticulum-Golgi complex mechanism?

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

Question 8

The specificity of hormones is 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
E) inactivation of hormones by the kidneys

Question 9

Which statement about 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) They may stimulate the secretion of other hormones and they target other glands.
E) All of these.

Question 10

Hormones

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

Question 11

Amines

A) consist of a chain of specific amino acids of varying length
B) are derived from the amino acid tyrosine
C) include the hormones secreted by the thyroid gland and adrenal medulla
D) all of these
E) are derived from the amino acid tyrosine and include the hormones secreted by the thyroid gland and adrenal medulla

Question 12

Which of the following is true 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.
E) They are all similar chemically.

Question 13

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

A) loose binding with albumin
B) specific binding to plasma proteins
C) as HDLs
D) loose binding with albumin and specific binding to plasma proteins
E) none of these

Question 14

Which statement 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 non-endocrine functions in addition to secreting hormones.
E) The same hormone may be secreted by more than one endocrine gland.

Question 15

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
E) adaptation to stress

Question 16

Select the incorrect statement about peptide hormones.

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.
E) They must bind to membrane receptors to invoke their actions.

Question 17

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

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

Question 18

All hormones

A) are regulated by the hypothalamus
B) initiate synthesis of new proteins
C) are secreted by endocrine glands through ducts into the blood
D) must combine with specific receptors on the target cells in order to exert their effects
E) are produced in a gland and target cells in different tissues

Question 19

Which statement regarding endocrine glands is incorrect?

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

Question 20

Neurosecretory neurons

A) release neurotransmitters
B) release hormones
C) are unable to conduct action potentials, unlike ordinary neurons
D) release neurotransmitters and hormones
E) all of these

Question 21

Which of the following is not shared by both lipophilic and hydrophilic hormones?

A) amplification of hormone actions in a cell
B) transport via plasma proteins
C) regulation of metabolic reactions
D) initiation of second messenger systems
E) transport via plasma proteins and initiation of second messenger systems

Question 22

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.
E) Thyroid hormone and TRH inhibit TSH secretion by the anterior pituitary.

Question 23

Which statement 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.
E) All hormones are regulated by other hormones.

Question 24

Permissiveness of hormones refers to the fact that:

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) The nervous system through numerous neuroendocrine relationships permits the endocrine system to function.
E) The tropic hormones permit other endocrine glands to secrete their hormones.

Question 25

Which class(es) of hormones uses second-messenger systems?

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

Question 26

The effective plasma concentration of a hormone can be influenced by the hormone's

A) rate of excretion
B) extent of binding to plasma proteins
C) rate of metabolic inactivation
D) rate of secretion
E) all of these

Question 27

Which of the following hormone types does not require membrane receptors to invoke cell responses?

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

Question 28

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

A) membrane receptors
B) G-proteins
C) intracellular receptors
D) adenylate cyclase
E) both intracellular receptors and adenylate cyclase

Question 29

The most common second messenger used by hydrophilic hormones is

A) calcium
B) cyclic AMP
C) chromatin
D) messenger RNA
E) plasma proteins

Question 30

The effective plasma concentration of a hormone is normally regulated by appropriate adjustments in the hormone's

A) rate of excretion
B) extent of binding to plasma proteins
C) rate of metabolic inactivation
D) rate of secretion
E) rate of binding with target-cell receptors

Question 31

Which of the following is least associated with the hydrophilic hormones?

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

Question 32

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

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

Question 33

In one kind of second-messenger system

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) Releasing hormones (the first messenger) from the hypothalamus regulate many anterior pituitary hormones (the second messenger).
E) A hormone (the first messenger) binds to surface receptors activating adenylate cyclase, catalyzing cAMP formation.

Question 34

Lipophilic hormones

A) include steroids and thyroid hormone
B) bind with receptors located inside their target cells
C) activate second-messenger systems within their target cells
D) include steroids and thyroid hormone and bind with receptors located inside their target cells
E) all of these

Question 35

Diurnal rhythms

A) 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) are important in maintaining hormone levels at a relatively constant set point no matter the time of day
C) occur only with cortisol secretion
D) 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 and occur only with cortisol secretion
E) none of these

Question 36

Steroids

A) are lipophilic
B) are derived from cholesterol
C) initiate the synthesis of specific new proteins within their target cells
D) are lipophilic and derived from cholesterol
E) all of these

Question 37

Select the correct statement about 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.
E) Its activity is unrelated to a set point.

Question 38

Select the incorrect statement.

A) Adenyl cyclase forms cyclic AMP.
B) Cyclic AMP is a secondary messenger.
C) Some hydrophilic hormones use Ca²⁺ ions as a secondary messenger.
D) Steroid hormones use second messenger to influence their target cells.
E) The hydrophilic hormone binds to a membrane receptor.

Question 39

Which statement 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.
E) Peptides are released by exocytosis upon appropriate stimulation.

Question 40

Estrogens, testosterone, cortisol, and aldosterone are all derived from what molecular precursor?

A) tyrosine
B) cholesterol
C) phospholipid
D) thyroglobulin
E) epinephrine

Question 41

Too little activity of a particular hormone can arise from

A) an abnormality within the endocrine gland that produces this hormone
B) a deficiency of this hormone's tropic hormone
C) an inborn lack of target-cell receptors for this hormone
D) deficient target-cell receptors
E) all of these

Question 42

Identify the gonadotropic hormone(s).

A) PRL
B) FSH
C) TSH
D) all of these
E) FSH and TSH

Question 43

Which of the following is a neurohormone?

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

Question 44

Melatonin is an antioxidant that

A) accelerates metabolism
B) defends against free radicals
C) lowers the concentration of blood sugar
D) serves as a secondary messenger
E) stimulates reduction reactions

Question 45

The posterior pituitary

A) secretes ADH
B) stores anterior pituitary hormones
C) stores ACTH and LH
D) secretes vasopressin and oxytocin into the hypothalamo-hypophyseal portal system
E) none of these

Question 46

Which structure(s) is/are neuroendocrine in nature?

A) anterior pituitary
B) posterior pituitary
C) hypothalamus
D) anterior and posterior pituitary
E) posterior pituitary and hypothalamus

Question 47

With regards to circadian rhythms

A) The hypothalamus' supraoptic nucleus maintains them.
B) The suprachiasmatic nucleus is responsible for generating them.
C) They are brought about by fluctuating levels of clock proteins.
D) The hypothalamus' supraoptic nucleus maintains them, and the suprachiasmatic nucleus is responsible for generating them.
E) The hypothalamus' supraoptic nucleus maintains them, and they are brought about by fluctuating levels of clock proteins.

Question 48

The posterior pituitary

A) is composed of nervous tissue
B) stores anterior pituitary hormones, which are released into the blood upon hypothalamic stimulation
C) synthesizes and secretes vasopressin and oxytocin
D) is composed of nervous tissue and synthesizes and secretes vasopressin and oxytocin
E) all of these

Question 49

Endocrine disorders resulting in too little hormone activity may stem from all of the following except

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

Question 50

Select the incorrect association.

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

Question 51

Which secretes insulin and glucagon?

A) posterior pituitary
B) liver
C) pancreas
D) stomach
E) adrenal medulla

Question 52

Hormone secretion from the anterior pituitary gland is controlled

A) by hormones from the hypothalamus
B) directly by neural innervation of anterior pituitary cells
C) by negative-feedback action of target-tissue hormones
D) by hormones from the hypothalamus and by negative-feedback action of target-tissue hormones
E) none of these

Question 53

The anterior pituitary

A) is also known as the neurohypophysis
B) is composed primarily of nervous tissue
C) primarily secretes tropic hormones
D) is also known as the neurohypophysis and primarily secretes tropic hormones
E) is composed primarily of nervous tissue and primarily secretes tropic hormones

Question 54

The ____ is the target for ACTH.

A) adrenal gland
B) anterior pituitary
C) posterior pituitary
D) ovary
E) none of these

Question 55

Melatonin's actions may include

A) regulation of circadian rhythms
B) antioxidant activity
C) induction of calcium reabsorption
D) regulation of circadian rhythms and antioxidant activity
E) none of these

Question 56

Which of the following has a direct anatomical connection to the hypothalamus?

A) adrenal gland
B) posterior pituitary
C) thyroid gland
D) parathyroid gland
E) none of these

Question 57

Melatonin is produced in which gland?

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

Question 58

Synergism occurs when:

A) One hormone induces the loss of another hormone's receptors.
B) The actions of several hormones are complementary, and their combined effect is greater than the sum of their separate effects.
C) 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) One hormone increases the number of target-tissue receptors for another hormone.
E) The number of target tissue receptors for a hormone is reduced as a direct consequence of the hormone's effect on its own receptors.

Question 59

Which of the following hormones secreted by the anterior pituitary is non-tropic?

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

Question 60

Which of the following hormones is released from the hypothalamus?

A) CRH
B) TSH
C) FSH
D) LH
E) GH

Question 61

Which is not a characteristic of oxytocin?

A) It stimulates uterine contractions.
B) It promotes milk ejection from mammary gland ducts.
C) It influences bonding behavior between mother and baby.
D) It is a tropic hormone.
E) None of these.

Question 62

Hormones produced in the anterior pituitary

A) are made in distinct populations of cells
B) may be tropic or nontropic
C) are secreted into the blood
D) are released in response to certain hormones
E) all of these

Question 63

Growth hormone

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

Question 64

The ____ releases corticotropin in response to ____ from the ____.

A) anterior pituitary; cortisol; hypothalamus
B) hypothalamus; cortisol; adrenal gland
C) adrenal gland; ACTH; anterior pituitary
D) anterior pituitary; CRH; hypothalamus
E) posterior pituitary; corticotropin-releasing hormone; hypothalamus

Question 65

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.
E) CRH inhibits cortisol secretion.

Question 66

Growth hormone

A) levels in the blood are directly correlated with the rate of growth throughout life
B) stimulates the secretion of somatomedins
C) stimulates osteoclast activity
D) stimulates the secretion of somatomedins and osteoclast activity
E) none of these

Question 67

Growth hormone

A) increases the uptake of amino acids by cells
B) promotes triglyceride breakdown
C) works with insulin to lower blood sugar
D) increases the uptake of amino acids by cells and promotes triglyceride breakdown
E) increases the uptake of amino acids by cells and works with insulin to lower blood sugar

Question 68

____ is the hypothalamic hormone that causes the anterior pituitary to release ____, thus, resulting in thyroid hormone release.

A) Thyroid-releasing hormone; thyroid-stimulating hormone
B) Thyroid stimulating hormone; thyrotropin-releasing hormone
C) Thyrotropin-releasing hormone; thyroid-stimulating hormone
D) Thyroid hormone; thyrotropin-releasing hormone
E) Thyrotropin-releasing hormone; thyroid hormone

Question 69

Which of the following hormones is regulated by the anterior pituitary?

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

Question 70

A portal system exists between the

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

Question 71

Which of the following is not a function of GH?

A) increases uptake of amino acids by cells
B) stimulates the synthesis of somatomedins
C) enhances glucose uptake by muscle cells
D) stimulates cell division
E) promotes bone growth until the epiphyseal plate is closed

Question 72

Which one of the following hormones signals the kidneys to control water balance?

A) vasopressin
B) ACTH
C) TRH
D) somatostatin
E) prolactin-inhibiting hormone

Question 73

The hypothalamo-hypophyseal portal system

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

Question 74

Growth hormone

A) directly stimulates bone growth
B) exerts its effects on bones via somatomedin release
C) promotes closure of the epiphyseal plate
D) directly stimulates bone growth and promotes closure of the epiphyseal plate
E) exerts its effects on bones via somatomedin release and promotes closure of the epiphyseal plate

Question 75

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.
E) It is released when the osmolarity of the plasma increases.

Question 76

LH stimulates the

A) cells that destroy the cells of Leydig
B) enlargement of the follicles
C) development of the hypothalamus
D) formation of the corpus luteum
E) water balance in the kidney

Question 77

Hypophysiotropic hormones

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
E) always act to stimulate the release of anterior pituitary hormones

Question 78

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
E) increased rate of cell division

Question 79

Which statement 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 of the hypothalamus, where they serve different functions.
D) Hypophysiotropic hormones are secreted into the general circulation.
E) None of these.

Question 80

Which pituitary hormone has no role in reproductive physiology?

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