Biology Endocrine System

Question 1

___ glands synthesize and secrete chemical substances called hormones directly into the circulatory system

Answer 1

endocrine

Question 2

In contrast, ___ glands, such as the gallbladder, secrete substances transported by ducts

Answer 2

exocrine

Question 3

The hypothalamic hormones regulate pituitary gland secretions via a ___ feedback loop

Answer 3

negative

Question 4

Releasing hormones are ___ into the hypophyseal portal system

Answer 4

secreted

Question 5

In the hypophyseal portal system, blood from the capillary bed in the ___ flows through a portal vein into the anterior pituitary (hypophyseal portal system), where it diverges into a second capillary network

Answer 5

hypothalamus

Question 6

Releasing hormones can immediately reach the anterior ___ without first entering the circulatory system

Answer 6

pituitary

Question 7

In the hypothalamus, the vast majority of feedback regulation is negative feedback, in which the product of the ___ inhibits its own production

Answer 7

pathway

Question 8

The pituitary gland hangs below the ___ and is connected to it by a slender cord known as the infundibulum

Answer 8

hypothalamus

Question 9

The ___ contains both the hypophyseal portal system and the neurosecretory axons, connecting the hypothalamus to the posterior pituitary gland

Answer 9

infundibulum

Question 10

The anterior pituitary synthesizes both direct hormones , which directly act on their target organs, and tropic ___, which stimulate other endocrine glands to release hormones

Answer 10

hormones

Question 11

The hormonal secretions of the anterior pituitary are regulated by hypothalamic hormones called ___/inhibiting hormones or factors

Answer 11

releasing

Question 12

(Tropic Hormones) Follicle stimulating hormone (FSH): In women FSH causes ___ of ovarian follicles which in turn secrete estrogen

Answer 12

maturation

Question 13

(Tropic hormones) Luteinizing hormone (LH): In women LH stimulates ___ and maintenance of the corpus luteum

Answer 13

ovulation

Question 14

(Tropic hormones) adrenocorticotropic hormone (ACTH): ACTH stimulates the adrenal cortex and secrete ___ and is regulated by corticotropin-releasing factor (CRF)

Answer 14

glucocorticoids

Question 15

(tropic hormones) thyroid-stimulating hormone (TSH):TSH stimulates the ___ gland to synthesize and release thyroid hormones, thyroxine (T) and triiodothyronine (T3)

Answer 15

thyroid

Question 16

(direct hormones) prolactin: ___ stimulates milk production in female mammary glands

Answer 16

prolactin

Question 17

(direct hormones) endorphins: These are ___ that have pain-relieving properties

Answer 17

neurotransmitter

Question 18

(direct hormones) growth hormone (GH, somatotropin): GH promotes bone and muscle growth. GH also promotes protein synthesis and lipid mobilization and ___

Answer 18

catabolism

Question 19

(direct hormones) melanocyte-stimulating hormone (MSH): MSH is secreted by the intermediate lobe of the ___. In mammals, MSH plays a role in the sun-induced darkening of skin (tanning). When amphibians are in darker environments for long periods of time, mSH is released causing darkening of skin in order to better camouflage with the environment

Answer 19

pituitary

Question 20

The ___ pituitary (neurohypophysis) does not synthesize hormones

Answer 20

posterior

Question 21

Instead, the posterior pituitary releases the peptide hormones oxytocin and ___ hormone, which are produced by the ___ cells of the hypothalamus

Answer 21

peptide, neurosecretory

Question 22

Oxytocin, which is secreted during childbirth, increases the strength and frequency of ___ muscle contractions

Answer 22

uterine

Question 23

___ secretion is also induced by suckling; oxytocin stimulates milk secretion in the mammary glands

Answer 23

oxytocin

Question 24

Antidiuretic hormone (ADH) increases water permeability in the ___ duct of the nephron, thereby promoting water reabsorption and increasing blood volume, which subsequently increases blood pressure and decreases blood osmolarity

Answer 24

collecting

Question 25

ADH is ___ when plasma osmolarity increases, as sensed by osmoreceptors in the hypothalamus, or when blood volume decreases, as sensed by baroreceptors in the circulatory system

Answer 25

secreted

Question 26

In response to stress, adrenocorticotropic hormone (ACTH), which is produced by the ___ pituitary, stimulates the adrenal cortex to produce more than two dozen different steroid hormones, collectively known as adrenocortical steroids or simply corticosteroids

Answer 26

anterior

Question 27

___ exert their action by determining which genes are transcribed in the nuclei of their target cells and at what rate

Answer 27

corticosteroids

Question 28

(corticosteroid) glucocorticoids, such as cortisol and cortisone, are involved in ___ regulation and protein metabolism

Answer 28

glucose

Question 29

(corticosteroid) Glucocorticoids raise blood glucose levels by promoting protein breakdown and ___ and decreasing protein synthesis

Answer 29

gluconeogenesis

Question 30

(corticosteroid) glucocorticoids are ___ to the effects of insulin and trigger the release of amino acids from skeletal muscle, as well as lipids from adipose tissue

Answer 30

antagonistic

Question 31

(corticosteroid) ___ also promote the peripheral use of lipids and have anti-inflammatory effects

Answer 31

glucocorticoids

Question 32

(corticosteroid) mineralocorticoids, particularly aldosterone, regulate ___ levels of sodium and potassium and, consequently, the total extracellular fluid volume

Answer 32

plasma

Question 33

(corticosteroid) ___ causes active reabsorption of sodium and passive reabsorption of water in the nephron of the kidney

Answer 33

aldosterone

Question 34

(corticosteroid) Active reabsorption of sodium and passive reabsorption of water results in an increase in both blood ___ and blood pressure

Answer 34

volume

Question 35

(corticosteroid) The ___ are stimulated by angiotensin II and inhibited by ANP (atrial natriuretic peptide0

Answer 35

mineralocorticoid

Question 36

(corticosteroid) The production of angiotensin II is regulated by the lungs and the ___, which are sensitive to blood pressure changes

Answer 36

kidney

Question 37

(corticosteroid) ___ (male sex hormones) are secreted from the adrenal cortex in small quantities in both men and women

Answer 37

androgens

Question 38

The adrenal medulla produces ___ (adrenaline) and norepinephrine (noradrenaline), both of which belong to a class of amino acid-derived compounds called catecholamines

Answer 38

epinephrine

Question 39

___ increases the conversion of glycogen to glucose in liver and muscle tissue, causing an increase in blood glucose levels and an increase in the basal metabolic rate

Answer 39

epinephrine

Question 40

Both epinephrine and norepinephrine increase the ___ and strength of the heartbeat and dilate and constrict blood vessels in such a way as to increase the blood supply to the skeletal muscles, heart, and brain, while decreasing the blood supply to the kidneys, sin, and digestive tract

Answer 40

rate

Question 41

Both epinephrine and norepinephrine will also promote the release of lipids by ___ tissue

Answer 41

adipose

Question 42

The ___ is controlled by thyroid-stimulating hormone (TSH) from the anterior pituitary, which is in turn stimulated by thyroid-releasing hormone (TRH) from the hypothalamus

Answer 42

thyroid

Question 43

The thyroid is located in front of the ___ and has two major functions, the first being metabolism regulation (including growth for children) through the release of triiodothyronine (T3) and thyroxine (T4)

Answer 43

trachea

Question 44

The second function of the thyroid is regulation of blood calcium levels through the release of ___, which has an antagonistic role with parathyroid hormone (produced in the parathyroid glands)

Answer 44

calcitonin

Question 45

The thyroid hormones, thyroxine (T4) and triiodothyronine (T3), are formed from the ___ thyroglobulin, which is synthesized in thyroid cells

Answer 45

glycoprotein

Question 46

(thyroid hormones) ___ is five times more potent than T4

Answer 46

T3

Question 47

(thyroid hormones) T4 and T3 are transported via plasma proteins. Approximately 99.5% of these hormones are bound to proteins, but only an unbound hormone is able to enter a cell and elicit a ___ response

Answer 47

cellular

Question 48

(thyroid hormones) All of the T4 in the body is formed and secreted by the ___ gland; however, only 20% of T3 is produced by the thyroid gland

Answer 48

thyroid

Question 49

___ decreases plasma CA2+ concentration by inhibiting the release of Ca2+ from bone and promoting the storage of Ca2+ in bones

Answer 49

Calcitonin

Question 50

Calcitonin secretion is regulated by plasma ___ levels

Answer 50

Ca2+

Question 51

Calcitonin is ___ to parathyroid hormone

Answer 51

antagonistic

Question 52

___ is not affected y the hypothalamus or the pituitary gland

Answer 52

calcitonin

Question 53

Gonadotropin-releasing hormone (GnRH) from the ___ acts on the anterior pituitary to release the gonadotropins (LH and FSH)

Answer 53

hypothalamus

Question 54

In men, both ___ and FSH act on the testes to produce testosterone and foster the maturation of sperm cells

Answer 54

Luteinizing hormone (LH)

Question 55

In females, the gonadotropins cause the secretion of ___ and protesterone

Answer 55

estrogen

Question 56

Gonadotropin-releasing hormone (GnRH) promotes the production of FSH and LH in the ___ pituitary which act on the gonads which then release testosterone or estrogen and progesterone

Answer 56

anterior

Question 57

Corticotropin-releasing factor (CRF) promotes the production of ___ hormone (ACTH) in the anterior pituitary which act on the adrenal cortex which then release glucocorticoids (cortisol and cortisone)

Answer 57

adrenocorticotropic

Question 58

Thyroid-releasing hormone promotes Thyroid-stimulating hormone (TSH) in the anterior ___ which acts on the thyroid which then release Triiodothyronine (T3) and Thyroxine (T4)

Answer 58

pituitary

Question 59

Dopamine promotes the production of Prolactin in the anterior pituitary which act on the ___ tissue

Answer 59

breast

Question 60

Growth hormone-releasing hormone (GHRH) promotes the production of growth hormone in the anterior pituitary which act on the ___ and muscle

Answer 60

bone

Question 61

A decrease in ___ from the hypothalamus promotes prolactin secretion

Answer 61

dopamine

Question 62

The parathyroid glands synthesize and secrete parathyroid hormone (PTH), which regulates ___ Ca2+ concentration

Answer 62

plasma

Question 63

PTH raises the ___ concentration in the blood by stimulating Ca2+ release from the bone and decreasing Ca2+ excretion in the kidneys

Answer 63

Ca2+

Question 64

Calcium in bone is bonded to ___, upon there being low Ca 2+ levels in the blood, and breakdown of the bone releases phosphate as well as calcium

Answer 64

phosphate

Question 65

Parathyroid hormone ___ for breakdown of the bone by stimulating excretion of phosphate by the kidneys

Answer 65

compensates

Question 66

The pancreas is both an ___ organ and an endocrine organ

Answer 66

exocrine

Question 67

The exocrine function of the ___is performed by the cells that secrete digestive enzymes into the small intestine via a series of ducts

Answer 67

pancreas

Question 68

The ___ function is performed by small glandular structures called the islets of Langerhans, which are composed of alpha and beta cells

Answer 68

endocrine

Question 69

Alpha cells produce and secrete ___, while beta cells produce and secrete insulin

Answer 69

glucagon

Question 70

The endocrine hormones of the ___ are regulated through negative feedback and are antagonistic to one another

Answer 70

pancreas

Question 71

___, a peptide hormone, is released by the pancreas when blood glucose levels are low

Answer 71

glucagon

Question 72

Upon release, glucagon stimulates ___ and fat degradation, the conversion of glycogen to glucose, and ___, all of which serve to increase blood glucose levels

Answer 72

gluconeogenesis

Question 73

___, a protein hormone, is secreted in response to a high blood glucose concentration

Answer 73

Insulin

Question 74

Insulin acts on ___ transporters on the cell membrane of liver, muscle, and adipose cells, resulting n the uptake of glucose

Answer 74

glucose

Question 75

___ also stimulates the synthesis of fats form glucose and the uptake of amino acids

Answer 75

Insulin

Question 76

The effects of insulin all serve to lower blood ___ levels

Answer 76

glucose

Question 77

The ___ plays a crucial role in the renin-angiotensin-aldosterone (RAA) system, which heavily regulates both blood volume and blood pressure

Answer 77

kidney

Question 78

When blood volume falls, the kidneys produce renin - an enzyme that converts the plasma protein ___ to angiotensin I

Answer 78

angiotensinogen

Question 79

Angiotensin I (produced by the liver) is converted to angiotensin II in the ___, which stimulates the adrenal cortex to secrete aldosterone

Answer 79

kidney

Question 80

___ helps restore blood volume by increasing sodium reabsorption by the kidneys, leading to an increase in fluid retention

Answer 80

aldosterone

Question 81

The kidneys also produce ___

Answer 81

erythropoietin (EPO)

Question 82

EPO is a glycoprotein that stimulates red blood cell ___; it is normally produced in the kidneys

Answer 82

production

Question 83

___ is carried to the gastric glands and stimulates the glands to secrete HCl in response to food in the stomach

Answer 83

gastrin

Question 84

The hormone ___ is released by the small intestine when acidic chyme enters from the stomach

Answer 84

secretin

Question 85

Secretin stimulates the secretion of an alkaline bicarbonate solution from the ___ that neutralizes the acidity of the chyme

Answer 85

pancreas

Question 86

The hormone ___ is released by the small intestine in response to the presence of fats and causes the contraction of the gallbladder and release of bile into the small intestine

Answer 86

cholecystokinin

Question 87

Bile, which is not a hormone, is involved in the ___ and digestion of fats

Answer 87

emulsification

Question 88

(Pineal gland) In primitive vertebrates, melatonin lightens the skin by concentrating pigment ___ in melanophores (melatonin is an antagonist to MSH)

Answer 88

granules

Question 89

___: amino acid chains

Answer 89

peptides

Question 90

Peptide hormones act as ___

Answer 90

first messengers

Question 91

When ___ bind to specific receptors on the surface of their target cells, they trigger a series of enzymatic reactions within each cell, the first of which may be the conversion of ATP to cyclic adenosine monophosphate (cyclic AMP); this reaction is catalyzed by the membrane-bound enzyme adenylate cyclase

Answer 91

peptides

Question 92

Cyclic AMP acts as a second messenger, relaying messages from the extracellular peptide hormone to ___ enzymes and initiating a series of reactions in the cell

Answer 92

cytoplasmic

Question 93

Cyclic AMP acting as a second messenger is an example of a ___ effect; with each step, the hormone's effects are multiplied

Answer 93

cascade

Question 94

Cyclic AMP activity is inactivated by the cytoplasmic enzyme ___

Answer 94

phosphodiesterase

Question 95

Because they are ___ soluble, steroid hormones cross the phospholipid bilayer and enter their target cells directly in order to bind to specific receptor proteins in the cytoplasm

Answer 95

lipid

Question 96

Upon binding to specific receptors in the cytoplasm, this receptor-hormone complex enters the ___ and directly activates the expression of specific genes by binding to receptors on the chromatin

Answer 96

nucleus

Question 97

___ mechanism of action involves binding to a receptor, inducing a conformational change, and regulating transcription at the level of the DNA

Answer 97

steroid

Question 98

Peptide hormones are quick while steroid hormones are ___

Answer 98

slow

Question 99

___ actions are short lived while steroid hormones are long-lived

Answer 99

peptide hormone