Adrenals Flashcards
What hormones does the zona glomerulosa produce ?
Mineralocorticoids (aldosterone)
what hormones does the zona fasciculata produce?
glucocorticoids: cortisol
what hormones does the zona reticularis produce?
androgens
what does the adrenal medulla produce?
catecholamines (epi and NE)
Aldosterone release is caused by:
RAAS activation
Hyperkalemia
Hyponatremia
aldosterone stimulates the kidney to conserve____ and ____ and excrete ____ and ____
conserve: sodium and h2O
excrete: K+ and H+
T/F: aldosterone regulates sodium concentration and osmolarity
FALSE! it does NOT regulate sodium concentration or osmolarity
What increases cortisol production?
Stress
Increased cortisol initiates:
gluconeogenesis
protein catabolism
fatty acid mobilization
Cortisol lessens (mitigates) the ____ cascade by reducing ______ release
lessens the inflammatory cascade
reduces cytokine release
cortisol improves _____ performance and is required for vasculature to respond to the vasoconstrictive effects of ______
myocardial performance
catecholamine
Adrenal Medulla synthesizes what two catecholamines in what amounts?
Epinephrine (80% of catecholamine output )
Norepinephrine (20% of catecholamine output)
What stimulates renin release?
-decreased renal perfusion (hemorrhage, PEEP, CHF, Liver failure, sepsis)
-SNS activation (beta-1)
-tubuloglomerular feedback
What kind of cells release renin?
Juxtaglomerular cells
ACTH only has _____ influence on aldosterone release.
minor
Thus explains why decreased ACTH does not cause hypoaldosteronism
the reabsorption of sodium and excretion of potassium and hydrogen by aldosterone causes:
1.) Fluid retention and expansion of extracellular space
2.) Decreased serum potassium concentration
3.) Metabolic alkalosis
T/F: aldosterone regulates sodium concentration and osmolarity
FALSE!
aldosterone regulates intravascular volume
T/F: sodium concentration does not change due to aldosterone
TRUE!
When sodium is reabsorbed into the peritubular capillaries, water follows in direct proportion= the sodium concentration does not change
What is osmolarity and sodium concentration controlled by?
ADH
ADH increases the reabsorption of _____ but NOT _____
water but NOT sodium
Increased water reabsorption dilutes sodium, and reduced water reabsorption concntrates sodium
T/F: cortisol does not interact with membrane-bound receptors
TRUE
It diffuses through the lipid bilayer and then binds with intracellular steroid receptors
T/F: cortisol influences protein synthesis inside the target cell
TRUE: cortisol activates or inhibits DNA transcription
these process require time, which explains the relatively slow onset of steroid medications
What is the normal cortisol production per day?
15-30 mg/day with a normal serum level of 12 mcg/dL
With stress what levels of cortisol will you see?
upwards of 100mg/day, with serum level up to 30-50mcg/dL during and after major surgery
How does cortisol produce energy mobilization?
Gluconeogenesis (amino acids are converted to glucose by the liver= increase blood sugar)
Protein catabolism (mainly muscle breakdown) = increased amino acid availability to the liver for gluconeogenesis
Fatty acid mobilization = increased FFA oxidation = increased ability to use fat for energy instead of glucose
How does cortisol produce anti-inflammatory effects?
Mitigates the inflammatory cascade by stabilizing lysosomal membranes and reducing cytokine release
- decreases # of esoinophils and lymphocytes in the blood
-cortisol does NOT reduce histamine release during an antigen-antibody response (accomplished by epi at the beta-2 receptor on mast cells and basophils)
What are the hemodynamic affects of cortisol?
Improves myocardial performance by increasing the number and sensitivity of beta receptors on the myocardium.
-Cortisol is also required for the vasculature to respond to vasoconstrictive effects of catecholamine
What are the hemodynamic affects of cortisol?
Improves myocardial performance by increasing the number and sensitivity of beta receptors on the myocardium.
-Cortisol is also required for the vasculature to respond to vasoconstrictive effects of catecholamine
Order each drug in terms of its glucocorticoid potency
cortisol
dexmethasone
methylprednisolone
aldosterone
1.) dexamethasone
2.) methylprednisolone
3.) cortisol (equal glucocorticoid and mineralcorticoid effects)
4.) aldosterone
Match each disease to its underlying pathophysiology
Conn’s syndrome
Cushing’s syndrome
Addison’s disease
excess aldosterone
excess cortisol
inadequate cortisol
Cushing’s syndrome = excess cortisol
Addison’s disease = inadequate cortisol
Conn’s syndrome = excess aldosterone
Etiologies of primary hyperaldosteronism (Conn’s syndrome)
Excessive aldosterone release from the adrenal gland- can be caused by adrenocortical hyperplasia or carcinoma
aldosteronoma
pheochromocytoma
primary hyperthyroidism
What will you see with Conn’s syndrome (to much aldosterone)
HTN
HYPOkalemia (u-waves and arrhythmias)
Hypokalemic metabolic alkalosis
increased extracellular fluid volume
DECREASED RENIN levels
What is the treatment for Conn’s syndrome?
surgical removal/medical management
-K+ supplementation
-antihypertensives
-spironolactone
-Eplerenone
- laparoscopic adrenalectomy
TX: FLUID AND SODIUM RESTRICT
will have weakness d/t hypokalemia= sensitive to all paralytics
What causes secondary hyperaldosteronism?
Stimulus of excess aldosterone outside the adrenal gland:
CHF
cirrhosis
ascites
nephrosis
exacerbates fluid and sodium retention
What are the symptoms of secondary hyperaldosteronism?
Increased renin levels
intravascularly dry
fluid volume overload
What is primary adrenocortical insufficiency called?
Addison’s disease
What causes Addison’s disease?
Mostly autoimmune destruction of the gland
Can be caused by infectious disease: TB, AIDS, fungal infections
What is insufficient in Addison’s disease?
Androgen, glucocorticoid and mineralcorticoids
What is intact in Addison’s disease?
HPA axis (adrenal-pituitary axis)
Are ACTH levels high or low in Addison’s disease?
ACTH concentrations are high d/t decreased cortisol
What is the treatment for Addison’s disease?
Replace glucocorticoids (anti-inflammatory) and mineralocorticoids (salt retention) = HYDROCORTISONE and FLUDROCORTISONE
Which steroid hormone has effects in virtually all cells in the body?
Glucocorticoids