Adrenal cortex Flashcards
What does the zona fasiculatata/reticularis produce
Cortisol, corticosterone, DHEA, and Andosterone
How does the ACTH/Cortisol loop work
Cortisol into blood, feed backs on pituitary and slows the production of ACTH
What does ACTH do
Stimulates growth and steroid production of zona fasiculata and reticualris of adrenal cortex
Can ACTH be used cross species
Yes
Who uses cortisol only
Cats, primates, horses
Who uses cortisol and corticosterone
Dogs
What uses corticosterone
birds, rats, mice
What are some tissues that glucocorticoids affect
Metabolic, immune, blood, skeletal
What are the metabolic effects of glucocorticoids
Promotes gluconeogenisis Stimulates lipolysis promotes protein breakdown glycogen formation inhibit glucose uptake catabolic
What is the only thing that the CNS can use for energy
glucose
What is the main function of adrenocortical steroids
maintain blood glucose
glycogen storage
what are the potencies of the corticoid hormones
Crotisol 3x > corticosterone = aldosterone
What are some immune functions of glucocorticoids
Potent anti-inflammatory role
Immunosuppression
Potential for infections
How do glucocorticoids influence blood
increase neutrophils, decrease lymphocytes
How do glucocorticoids affect skeletal system
promote bone breakdown
Inhibits vit D
What does cortisol do at high level to T-lymphocytes
inhibit T-lymphocytes
What is the function of DHEA
primary androgen
Why are DHEA and aldosterone important
may play a role in development of secondary sexual characteristics at puberty
Substrates for estrogens
anti-aging
What are the effects of mineralocorticoids
Promote Na retention and K elimination
Water retention
H ion elimination
What is an example of a mineralcorticoid
aldosterone
What is another name for Hyperandrenocorticim
cushing
What is the most common cause of spontaneous Cushing
excessive ACTH production
where is Cushing syndrome most common
Older dogs
What is suppressed in animals with primary adenocortical tumors
ACTH and CRH
What is iatrogenic Cushings
Cushing disease caused by the Dr.
What is a cause of iatrogenic Cushing caused by a Dr.
Exogenous glucocoritcoids causing clinical signs of cortisol excess.
Stop giving glucocorticoids
Atrophy of zona fasiculata
Adrenal supression
What are some symptoms of Cushing
Polydipsia and polyuria
Hyperphagia
Abdominal enlargement
How quick does Cushing progress
slowly
What are the catabolic effects of Cushing
Increase blood glucose
Muscle wasting
Thin skin
Decreased bone density
How do you diagnose Cushing
Elevated cortisol
ACTH challenge
-increased capacity to make cortisol
Dexamethasome test (DEX)
What are two types of Cushing
Pituitary-dependent hyperandrenocorticism (PDH)
-more common
Primary hyperandenocorticism
PHD is caused by
increased ACTH production
Primary hyperadrenocorticism is caused by
adrenal tumors
What does a low does DEX treatment determine
If animal has Cushing
What doesn’t low dose DEX determine
difference between tumor and PHD Cushing
What does High-dose DEX test do
Suppress cortisol levels in PDH patients, but Cushing caused by a tumor
What will ACTH levels be in dogs with PDH
higher than normal
What will ACTH levels be in dogs with adrenal tumors
Lower than normal
What is the most common treatment of PDH
Lysodren
What does Lysodern do to treat PDH
Selective necrosis of zona fasiculata and reticularis
What would happen if you gave too much Lysodren to a dog
cause hypoadrenocorticism
What is Addison disease
Hypoadrenocorticism
What is difference between primary and secondary diseases in Addison and Cushing disease
Cushing- treated the same
Addison- different treatments
What do you use to diagnose secondary Addison
ACTH
What is the most common cause of primary adrenocortical failure
Autoimmune
What is an important cause of secondary Addison
Iatrogenic (caused by clinician)
How long does it take for ACTH to recover
months
What is the treatment of primary Addison
Saline followed by glucocoriticoids and mineral corticoids (on exam last year)
What is the treatment for secondary Addison
Glucocorticoid treatment (no mineralcoritoids [on exam last year])
What does the zona glomerulosa produce
Aldosterone
