Lecture 64- Adrenal Cortex Flashcards
What are the net effects of cortisol?
Catabolic
What is the only time of cortisol that is biologically active?
Free cortisol
Why are the effects of cortisol described as “permissive”?
-doesnt directly initiate actions but allows other critical processes to occur
-amplifies actions of other hormones
What are the 4 effects of cortisol on energy metabolism?
- Increases blood glucose
- Increases glycogenesis
- Increases lipolysis and protein catabolism
- Increases appetite, visceral obesity
How does cortisol increase blood glucose (3)?
- Increase gluconeogenesis
- Increase glucagon release from pancreas to allow glycogenolysis
- Temporary causing insulin resistance in tissues
What does cortisol inhibit?
Calcium absorption
What is the effect of cortisol on the musculoskeletal system?
Increases protein catabolism
What effect does cortisol have on bone, specifically? (3)
- Inhibits bone formation
- Increases bone resorption
- Causes osteoporosis
What effect does cortisol have on connective tissue, specifically? (2)
- Inhibits collagen synthesis
- Causes thin skin and fragile capillaries (if cortisol is high long-term)
What effect does cortisol have on the kidneys and cardiovascular system? What does it increase and what does it decrease?
Has a role in water balance !!!!
Increases glomerular filtration rate in the kidney
Decreases ADH
What does cortisol help maintain in the kidneys and cardiovascular system?
Maintain normal blood pressure and volume
Which receptors does cortisol upregulate in the kidney and cardiovascular system? What is this specific receptor necessary for?
-upregulates alpha-1 adrenergic receptors
-necessary for vasoconstrictive response of arterioles to NE and EPI
What effect does cortisol have on the immune system? (3)
- Suppresses immune response
- Decreases neutrophil activity, formation of cytokines, T-lymphocytes, and antibody formation
- Specific anti-inflammatory effects
What specific anti-inflammatory effects does cortisol have on the immune system?
-induces lipoprotein
-inhibits production of interleukin-2
-inhibits release of histamine
When lipocortin is induced, it inhibits ______, thus decreasing ______ and _________.
Inhibits phospholipase A2
Decreasing precursors of prostaglandins and leukotrienes
What are exogenous steroids administered?
Suppress the immune system and prevent rejection of transplanted organs
combat hyper immune reactions
What is needed for androgen pathway in the zone reticularis?
17,20-lyase
What are considered (3) weak androgens in the Zone reticularis? And what are these converted to in peripheral tissue?
- DHEA
- DHEA sulfate
- Androstenedione
**Converted to testosterone and estrogen
What is the innermost cortical layer?
Adrenal cortex: Zona reticularis
What is slope is caused by?
-an elevation in androgens and/or sex steroids
What are the clinical signs of hyperaldosteronism? What is the treatment?
Increased ECF volume, increased renal perfusion pressure
Treatment: spironolactone (aldosterone antagonist)
How does the primary form of hyperaldosteronism differ from the secondary form?
Primary form: idiopathic adrenal hyperplasia. Tumors are present.
Secondary form: liver disease, kidney disease (RAAS pathway is activated, BP increases)
What are the causes of Addison’s disease (hypoadrenocorticism)?
Auto-immune, infiltrative disease, idiopathic, iatrogenic steroids
*anything that could destroy adrenal gland (tumor, hemmoraghe)
*cancer (accumulation or diffusion in cells or tissues of substances normally not found)
What does the loss of cortisol in addisons disease result in?
Decreased gluconeogenesis and blood glucose
What does the loss of aldosterone in addisons disease result in? (There are a lot RIP)
Increased K+ , decreased blood volume, decreased Na+, bradycardia, irregular heartbeat, circulatory collapse
What is another name for hypoadrenocorticism?
Addisons disease
What is another name for hyperadrenocorticism?
Cushing’s syndrome
What are the causes of Cushing’s syndrome?
Excess cortisol production, pituitary adenoma secreting excess ACTH, loss of tonic dopamine inhibition of ACTH, adrenal tumors
What is pars intermedia dysfunction? What species is it common in? (related to Cushings syndrome)
Loss of tonic dopamine inhibition of ACTH
Common in horses
What does chronic excessive exogenous steroid administration result in ?
Latrogenic hyperadrenocorticism
