Steroid Hormone

Front 1

what are the five classes of steroid hormones?

Back 1

glucocorticoids, mineralocorticoids, androgens, estrogens, progestins

Front 2

what glands/organs produce these steroid hormones?

Back 2

adrenal gland-GC, MC, androgens. Gonadal(ovaries, testes)--androgens, estrogens, progestins

Front 3

sources of cholesterol?

Back 3

acetyl CoA, cholesterol esters, LDL from plasma

Front 4

what hormones stimulate the adrenal and gonadal tissue to secrete steroid?

Back 4

ACTH, FSH, LH, angiotensins, oxytocin

Front 5

fcn of ACTH?

Back 5

adrenal corticotrophic hormone, leads to synthesis/secretion of GC (cortisol)

Front 6

are hormones synthesized and activated in the same site?

Back 6

no. hormones must travel from sites of synthesis to sites of action

Front 7

how are hormones transported in the blood to target tissues?

Back 7

carriers-albumin(nonspecific), sex hormone binding globulin, cortisol-binding globulin

Front 8

fate of steroid hormones/

Back 8

inactivation in liver or other tissues (oxidation, conjugation with glucuronic acid/PAPS) excretion in urine

Front 9

where does the steroid synthesis begin?

Back 9

mitochondria

Front 10

how are hormones synthesized?

Back 10

receptor binds to stimulus→CE hydrolase activated→free cholesterol released→diffuses into mito membrane→StAR protein helps transfer cholesterol to inner membrane

Front 11

fcn of StAR?

Back 11

steroidogenic acute regulatory protein- helps trnasfer choleserol to inner mito membrane

Front 12

what enzyme does the synthesis of GC and MC require?

Back 12

P450 enzymes

Front 13

significance of P450 enzymes?

Back 13

rate determining step in synthesis of GC and MC from cholesterol to pregnenolone

Front 14

fcn of P450?

Back 14

helps transfer e- from NADPH to O2, which oxidizes ring C of cholesterol

Front 15

significance of progesterone?

Back 15

precursor of MC and GC syntehsis→leads to aldosterone (C21) and cortisol (C21)

Front 16

significance of androstenedione?

Back 16

precursor for sex hormone synthesis→leads to testosterone (C19)→estradiol(C18), estrone(C18)

Front 17

structure of aldosterone?

Back 17

aldehyde at C18 (C21)

Front 18

structure of cortisol?

Back 18

alcohol at C17 (C21)

Front 19

fcn of cortisol?

Back 19

stimulate muscle protein breakdown (like glucagon), also redirects muscle protein to cells in immune response and wound healing

Front 20

effects of cortisol to muscle?

Back 20

stim protein breakdown→dec protein syntehsis→dec amino acid uptake

Front 21

effects of cortisol to liver?

Back 21

stim amino acid uptake→stim protein synthesis

Front 22

fcn of aldosterone?

Back 22

increases Na and water reuptake in kidney, increases blood volume (and BP)

Front 23

what is aldosterone secreted in response to?

Back 23

angiotensin II, III→ results cuz of inc K+ levels, dec. Na

Front 24

primary defect in hypofunctions of adrenal cortex?

Back 24

adrenal tissue unable to produce enough hormone (AIDS)

Front 25

secondary defect in hypofunctions of adrenal cortex?

Back 25

inadequate formation or release of ACTH (hypothalamic-pituitary disease, tumor)

Front 26

what symptoms reveal something wrong with adrenal gland?

Back 26

low serum cortisol level, unresponsive

Front 27

what is Addison's disease?

Back 27

primary adrenocortical deficiency. Destruction of cortisol/aldosterone due to autoimmune disease or cancer/infection

Front 28

what causes production of low mineralocorticoids?

Back 28

electrolyte imbalance(hyponatremia-low Na, hyperkalemia-high K)

Front 29

what causes excretion of Na?

Back 29

dehydration

Front 30

what causes hypoglycemia?

Back 30

defiency in cortisol, which can inhibit release of insulin and stimulate release of glucagon

Front 31

what can cause weakness and fatigue?

Back 31

low glucose, inability to optimally run gluconeogenic pathway

Front 32

what natural mechanisms does cortisol deficiency prevent?

Back 32

fighting infections, and controlling inflammation

Front 33

what is the ACTH test?

Back 33

if supply synthetic ACTH restores normal cortisol levels, then suspect destruction of endocrine fcn of pituitary

Front 34

what is Cushing's disease?

Back 34

hyperfunction of adrenal cortex. Overactive adrenal gland, excess adrenal hormones

Front 35

what can cause hypersecretion of ACTH?

Back 35

small pituitary adenoma(tumor) →leads to adrenal hyperplasia

Front 36

symptoms of Cushings disease?

Back 36

moon shaped face, abdominal bruising stretch marks(elastin breakdown), hypertension, increased cortisol weakness

Front 37

what can cause high ACTH levels?

Back 37

ACTH producing tumor,

Front 38

what can cause low ACTH levels?

Back 38

adrenal tumor

Front 39

what results in redundancy of enzymes in steroid hormone synthesis?

Back 39

defects leading to multiple abnormalities

Front 40

what hormones decrease in production by CYP21 deficiency?

Back 40

aldosterone, cortisol

Front 41

what is congenital adrenal hyperplasia (CAH)

Back 41

cyp21 defiency, adrenal tumor→menstrual irregularity, enlarged adrenal glands, ambiguous genitalia, hyponatremia

Front 42

what hormones increase due to CYP21 defiecny?

Back 42

back up of progesterone, more go to androgens, inc aCTH virulization

Front 43

what hormones increase due to CUP11B1 defiency?

Back 43

DOC(right after progesterone), hypertension ACTH virilization

Front 44

treatment of CAH? Congential adrenal hyperplasia?

Back 44

daily administration of GC to supress overproduction of aCTH

Front 45

what can reveal MC excess?

Back 45

Na retention, hypertension, hypkalemia, cortisone NOT recognized byeither receptor

Front 46

what is the cortisol-cortisone shunt?

Back 46

cant bind to cortisol receptors→reveals MC excess

Front 47

what hormones are overproduced due to CYP17 defiency?

Back 47

aldosterone and hypertension without virilization.

Front 48

what hormones decrease in production by CYP17 deficiency?

Back 48

adrenal androgens-DHEA, androstenedione

Front 49

fcn of DHEA?

Back 49

connection with immune function. Decinles with age, low in AIDS

Front 50

what hormone increases when there is a deficiency in cortisol synthesis (CAH)?

Back 50

adrenal androgens

Front 51

where does sex hormone synthesis taek place?

Back 51

adrenal, testes, ovaries

Front 52

what activates androgen synthesis in testes?

Back 52

Luteinizing hormone (LH) to make testosterone

Front 53

what activates estrogen and progestagin syntehsis in ovaries?

Back 53

follicle stimualting hormone (FSH)

Front 54

what pathway is mainly used to form testosterone?

Back 54

the one that involves DHEA

Front 55

rate determining step for productionof testosterone?

Back 55

cholesterol(C27)→pregnenolone(C21)

Front 56

significance of dihydrotestosterone (DHT)?

Back 56

higher affinity form of testosterone, potent. Occurs in target tissues prior to receptor binding

Front 57

significance of progestagens and estrogens?

Back 57

thickening of endometrium for pregnancy, develop mammary glands

Front 58

what can estrogen prevent?

Back 58

bone loss

Front 59

where is progesterone made?

Back 59

corpus luteum (ovary) and placenta

Front 60

fcn of progesterone (C21)?

Back 60

prepares uteral lining during ovulation, maintains pregnancy

Front 61

what stimualtes synthesis of progesterone?

Back 61

FSH

Front 62

how many carbons do progesterone and estradiol have?

Back 62

C21/C19 to C18

Front 63

where is estriol made?

Back 63

placenta---testosterone→estradiol

Front 64

what is the major source of estrogens in post-menopausal women?

Back 64

estrone (C18)

Front 65

what happens when there is accelerated bone resoprtion?

Back 65

increases loss of Ca, and suppresses renal Vit D production

Front 66

fcn of Vit D?

Back 66

affects Ca homeostasis, modulates bone modeling

Front 67

what is the major Vit D form in plasma?

Back 67

25 hydroxylation (calcidiol) in liver

Front 68

what is the committed step in Vid D formation?

Back 68

cholecalciferol to calcidiol

Front 69

what is the rate determining step in Vit D formation?

Back 69

25 fydrozycholecalciferol(calcidiol)→1,25-(OH)2D3 (1 hydroxylation)

Front 70

where does the RDS in Vit D formation take place?

Back 70

kidney

Front 71

what stimulates RDS in vit D formaiton?

Back 71

parathyroid hormone