Class 4 Adrenal Flashcards
The adrenal are responsible for releasing what kind of hormones?
Stress hormones
Where are the adrenals located? and What are the two areas of the adrenals?****
- Atop the kidneys
- Cortex = outer layer
- Medulla = Inner region
The adrenal medulla is connected directly to the what?****
-Sympathetic nervous system
What does the adrenal medulla release? And what do they activate?
- catecholamines
- Fight or flight response
What are catecholamines derived from? And what cells make them?****
- Tyrosine
- Chromaffin cells
4 types of catecholamines?****
- DOPA
- Dopamine
- Norepinephrine
- Epinepherine
Where is the only place epinepherine is made?***
-Adrenal medulla
what 2 substances cause sympathetic activation?
-Epi and norepi
What does sympathetic activation do?
- Mobilizes resources (HR, BP, glucose, bronchodilation)
- Downshifts less needed resources
What do epi an norepi have in common? how are they different?****
- Both have strong alpha effects which cause arterial vasoconstriction
- Epi has stronger beta effects which increases HR
Pheochromocytoma is a tumor either caused by _______ or extra-adrenal ______ tissue
- Adrenal hyperplasia
- chromaffin
Pheochromocytoma symptoms include.
- Paroxysmal HTN
- Tachycardia
- Head ache
- Sweating
- anxiety
- Tremor
- Glucose intolerance
How to diagnose a pheochromocytoma?
- Clinical suspicion
- Urinary vanillylmandemic acid (epi and norepi are degraded to this)
- Ultrasound or MRI
pheochromocytoma preop considerations.
- Alpha blockers started 10-14 days prior to surgery
- Once alpha blockade is established beta blockade can begin****
- When arteries relax, volume expansion is needed
Name 2 alpha blockers
- Phenoxybenzamine
- Prazosin
When do catecholamine levels return to normal after removal pheochromacytome?
-75% w/i 10 days post op
What type of vasoactive agents should be used during surgery to remove pheochromocytoma?
Short acting due to bouts of hypo and hyper tension with tumor manipulation
Why is medullary hyposecretion generally not a problem?
- sympathetic nervous system compensates for CV regulation
- Other hormones compensate for metabolic effects
the adrenal cortex mediates the stress response via the production of what?
- Mineralocorticoids
- glucocorticoids
- androgens
what are the 3 zones of the adrenal cortex and what do they produce?*** And they are all synthesized from what?
- glomerulosa = mineralocorticoids
- fasciculata = glucocoticoids
- reticularis = androgens
- Cholesterol***
What is the primary mineralocorticoid? glucocoticoid? androgen?***
- Aldosterone
- Cortisol (hydrocortisone)
- androstendione
what does mineralocorticods (aldosterone) control?*****
- Retention of Na and H2O while excreting K and H+
- affecting water balance and BP
if unopposed what will aldosterone do?
- Hypertension
- ECF expansion
- Hypokalemia
- Alkalosis
What is Conn’s syndrome? and what causes it? and how is it diagnosed?
- Primary hyperaldosteroneism
- Aldosterone secreting tumors or hyperplasia
- low renin from negative feedback
What are the effects of Conn’s syndrome?
- Increased ECF
- HTN
- K depletion
- Alkalosis
What causes secondary hyperaldosteronism?
-CHF
-Cirrhosis w/ ascites
-nephrosis
(intravascular volume depletion triggers renin)
Hypoaldosteronism (adrenal insuffiency) can cause what?
- Na loss and K retained
- Plasma volume decrease
- hypotension/hyperkalemia = circulatory collapse
What 3 things does glucocorticoids do?
- Stimulate gluconeogenesis
- Decrease glucose utilization by the cells
- Elevates blood glucose
how do glucocortidoids (cortisol) elevate blood sugar?
- Increase in formation of glucose by liver
- decrease utilization of glucose by tissue
Almost any stress (physical or neurogenic) can cause an immediate release of ____ by the anterior pituitary gland followed by greatly increased secretion of ______
- ACTH
- Cortisol
How does cortisol prevent inflammation?
- Stabilizing lysosomes
- decreasing capillary permeability
- Decreasing WBC migration
Explain the negative feedback loop for glucocorticoids?
- Physiological stress sensed by hypothalamus and CRH is released
- CRH stimulates ACTH release
- ACTH stimulates cortisol release
____, ______, and _____ are released in relation to circadian rhythms with high levels in the morning
CRF, ACTH, and Cortisol
What is the difference between cushings’s disease and cushings’s syndrome?
- Disease = ACTH secreting tumor
- Syndrome = excessive cortisol secretion
What is the opposite of cushing’s? What does it do?
- Addison’s disease
- Failure to produce cortisol
What is the difference between primary ad secondary addison’s?
- Primary = adrenal nonfunction (autoimmune)
- Secondary = hypothalamic or pituitary non function
Symptoms of addison’s disease (glucocorticoid/cortisol deficiency)
- Hypoglycemia
- Hyperpigmentation
- Stress deterioration
Risk of cardiovascular collapse due to low cortisol and stress is called what?
- Addisonian crisis
- Treat with cortisol
Chronic steroid usershave experienced periop shock and even death when these meds are held what is the cause?
- Acute adrenal insufficiency
- Give large doses of glucocorticoids preop
What medicine can cause suppression of cortisol and adrenal insufficiency?
Etomidate
80% of the adrenal medulla output is what? the other 20%?
- 80= Epinepherine
- 20= Norepi
