Adrenal Medulla And Cortex

Front 1

briefly describe the synthesis of norepi and epi

Back 1

tyrosine is converted to DOPA via thyrosine hydroxylase

DOPA is decarboxylated to Dopamine

dopamine is hydroxylated to norepi

norepi is methylated to epi

Front 2

what leads to the activation of tyrosine hydroxylase

Back 2

preganglionic sympathetic innervation required for catecholamine synthesis
- Ach action at nicotinic cholinergic receptor

Front 3

under basal conditions what is higher in the plasma norepi or epi

Back 3

norepi

Front 4

under certain stimulated states what is higher in the plasma norepi or epi

Back 4

epi

Front 5

give an example when epi might be higher than norepi in the plasma?

Back 5

hypoglycemia

Front 6

name actions that are produced through the action of mainly alpha-1 adrenergic receptors?

Back 6

vasoconstriction

relaxation of intestinal SM

pupillary dilation

contraction of internal sphincter of bladder

contraction of uterine SM

Front 7

name the effects of stimulation of beta 2 adrenergic receptors

Back 7

vasodilation

bronchodilation

relaxation of uterine SM

increaed glycolysis

decreased glucose utilization

Front 8

name the effects of stimulation of beta 1 adrenergic receptors

Back 8

cardioacceleration

positive inotropism

increased lipolysis

Front 9

name the effects of stimulation of beta 3 adrenergic receptors

Back 9

increased lypolysis

Front 10

how are catecholamines cleared?

Back 10

converted to inactive products
-VMA
-MOPEG

Front 11

what enzymes are necesary for the conversion of catecholamines so they can be cleared?

Back 11

MAO - conversion to VMA

COMT - conversion to MOPEG

Front 12

what is a pheochromocytoma?

Back 12

excessive production of catecholamines

its a tumor of adrenal chromaffin cells

Front 13

name some common signs associated with pheocromocytoma

Back 13

episodic hypertension

severe headache

excessive sweating

palpitations with/without tachycardia

Front 14

what does the zona glomerulosa produce as a final product

Back 14

aldosterone

Front 15

what is the primary substrate for the products of all three zones of the adrenal cortex?

Back 15

cholesterol

Front 16

what is a similarity between the three layers of the zona

Back 16

use CYP11A1 to convert cholesterol to pregnenolone

Front 17

what is the pregnenolone converted to in both the zona glomerulosa and fasciculata and why can the same thing not happen in reticularis?

Back 17

progesterone

reticularis is missing the necessary enzyme

Front 18

what is the product of zona fasciulata

Back 18

cortisol

Front 19

what is the product of zona reticularis

Back 19

DHEA or andronstenedione

Front 20

what is the rate determining step of steroid synthesis

Back 20

conversion of cholesterol to pregnenolone

Front 21

what is the secretogogue of zona glomerulosa

Back 21

ang II

Front 22

what is the secretogogue of zona fasciculata

Back 22

ACTH

Front 23

was is the secretogogue of zona reticularis

Back 23

ACTH

Front 24

how is cortisol found in the bloodstream?

Back 24

75% bound to CBP

15% albumin

10% free

Front 25

how is aldosterone transported through the bloodstream

Back 25

50% albumin
40% is free
10% bound to CBP

Front 26

how is DHEA-sulfate transported through the bloodstream

Back 26

98% is bound to albumin

2% is free

Front 27

describe the mechanism of action of steroid hormones

Back 27

they are lipid soluble
diffuse across the plasma membrane
through nuclear localizing signal transported to nucleus
have genomic effects

Front 28

give an example of a glucocorticoid

Back 28

cortisol

Front 29

what are some metabolic effects of cortisol

Back 29

stimulation of gluconeogenesis in the liver
stimulation of glycogenesis in the liver
increased protein catabolism-negative nitrogen balance
increased lipolysis

Front 30

what are permissive effects of cortisol?

Back 30

permissive - action of one hormone enables the full effect of another hormone

cortisol enhances action of NE at alpha-adrenergic receptors in VSM

Front 31

describe the circadian rhythm of ACTH and cortisol

Back 31

increased ACTH correlates with increased cortisol levels

there are increasing level of these hormones in the early hours- importnant for having systems ready for metabolic activities during the day

Front 32

describe the regulatoin of glucocorticoid release

Back 32

ACTH acts at adrenal corticol cells

there s negative feedback of ACTH ath the level of the hypothalamus and anterior pituitary via cortisol

ACTH also has a negative feedback at the level of the hypothalamus

Front 33

what is the effect of long term use of exogenous glucocorticoids

Back 33

ex: prednisone for arrthritis

suppresses the HPA axis

has negative effects at the level of anterior pituitary and hypothalamus which drastically reduces ACTH release

the result is reduced cortisol secretion as well as atrophy of adrenal cortex

Front 34

what would be the effect of removing an individual from long term use of exogenous glucocorticoids?

Back 34

within a month the ACTH levels recover
cortisol concentrations stay below normal levels for up to six months after stopping the medication

Front 35

what is addison's disease?

Back 35

primary adrenal insufficiency

inability of the fasciculata tissue to produce cortisol

will see low levels of cortisol but elevated levels of ACTH - feedback normally provided by cortisol is absent

Front 36

describe secondary adrenal insufficiency

Back 36

inability of AP to produce ACTH

diminished levels of ACTH leads to low levels of cortisol

Front 37

what are some signs and symptoms of addisons disease

Back 37

brain: lethargy, dizziness, depression
muscles: skeletal muscle weakness and fatigue
intestines: abdominal pain, constipation
skin: increased pigmentation due to increased levels of cortisol
blood pressure: postural hypotension

Front 38

what three conditions fall under Cushing's syndrome

Back 38

cushing's disease

adrenal tumor

ectopic tumor

in all cases there is adrenocortical hyperfunction

Front 39

what is cushing's disease

Back 39

hypersecretion of ACTH by AP - excessive production of cortisol

Front 40

describe how an adrenal tumor would be different when compared to cushing's disease

Back 40

produces high amounts of cortisol but low levels of ACTH

Front 41

how is an ectopic tumor different than an adrenal tumor or cushing's disease?

Back 41

not found in adrenal tissue
pumps out lots of ACTH resulting in elevated levels of cortisol

Front 42

how could you distinguish between an ectopic tumor vs cushings?

Back 42

they both produce high levels of ACTH

but if give drug to negatively feedback of ACTH and see modest reduction the problem is in the anterior pituitary

if you give the drug and see no reduction - ectopic tumor

Front 43

what is the most common enzyme deficiency in adrenal steroid biosynthesis and what is the effect?

Back 43

21alpha - hydroxylase deficiency

you will have excess androgen production from the reticularis and inadequate production of cortisol and aldosterone

the enzyme is necessary in the production of aldosterone and cortisol

Front 44

what happens when there is a 11beta-HSD deficiency

Back 44

this is normally necessary for conversion of cortisol to corticosterone

when its inhibited cortisol levels will rise and stimulate mineralcorticoid receptor

Front 45

why is eating too much licorice a bad thing?

Back 45

contains glycerrhetinic acid which is an inhibitor of 11beta-HSD

excessive amounts of licorice can lead to cortisol stimulation of gene expression in prinicpal cells of the kidneys which can mimic aldosterone actions

can lead to volume dependent elevation in blood pressure

Front 46

what is the most important mineralcorticoid?

Back 46

aldosterone

Front 47

what is the action of aldosterone?

Back 47

acts on epithelial cells of distal collecting tubules of kidney

promotes reabsorption of Na+ and secretion of K+

stimulates H+ secretion

Front 48

where else in the body does aldosterone stimulate Na+ reabsorption

Back 48

salivary glands

sweat glands

colon

Front 49

what is the affect of aldosterone on the heart?

Back 49

fibrosis

Front 50

describe the renin-angiotensin system

Back 50

angiotensiongen produced in the liver is changed by renin from JG cells into angiotenisn I

angI is converted to ang II by ACE

AngII causes release of aldosterone which causes increased Na+reabsorption and K secretion

Front 51

describe conn syndrome

Back 51

primary hyperaldoseronism

adrenal glomerulosa tumor---increaed aldosterone production----increase Na reabsorption and increased ECFV-increaed ABP----decreaed JGA renin release

Front 52

describe secondary hyperaldosteronism

Back 52

decreased renal perfusion pressure-----increased JGA renin release - - increased aldoseronism---increased Na reabsorption and increaed ECVF---increased ABP

Front 53

what happens with a defect in 11beta hydroxylase enzyme

Back 53

second most common defect in adrenal steroid biosynthesis

aldosterone and cortisol levels greatly decreased

there is an excessive production of 11- deoxycorticosterone(DOC) which is an effective mineralcorticoid

Front 54

what is primary hypoaldosteronism

Back 54

addisons disease

adrenal glomerulosa cell dysfunction---decreased aldosterone---- decreaed Na reabsorption decreaed ECFV---decreaed ABP ----increaed JGA renin release

Front 55

what is secondary hypoaldosteronism

Back 55

renal insufficiency------decreaed JGA renin release------decreaed aldosterone releae---- decreased Na+ reabsorption and decreaed ECFV---decreaed ABP