Adrenal Glands Flashcards
adrenal glands are often very hard to find on necropsy. what anatomic structure can you use to ID adrenal gland location?
phrenicoabdominal vein
tell me the gross appearance of a normal adrenal gland
1:2:1 cortical:medullary:cortical ratio
outer cortex is yellow
inner medulla is dark red
what are the zones of the adrenal cortex from outside to inside
zona glomerulosa
zona fasiculata
zona reticularis
the adrenal medulla produces what?
catecholamines (epinephrine and norepinephrine)
the zona glomerulosa produces what?
mineralocorticoids, like aldosterone
the zona fasiculata produces what?
glucocorticoids, like cortisol
the zona reticularis produces what?
sex hormones, like progesterone, estrogen, androgens
the zona glomerulosa secretes mineralocorticoids. this process is regulated by ____? this process acts on _____?
renin-angiotensin
distal convoluted tubules
what do mineralocorticoids do? so if there’s mineralocorticoid dysfunction, what happens?
excretion of potassium and resorption of sodium (and water follows sodium)
potassium is not excreted (increased K) and sodium is not resorbed (decreased Na)
the zona fasiculata secretes glucocorticoids. this process is regulated by ____?
ACTH
what do glucocorticoids do? what are the consequences?
sparing of glucose - gluconeogenesis, lipolysis, protein catabolism
suppress inflammation/immunity
negative effect on wound healing
the zona reticularis releases sex hormones. this process is regulated by ____.
ACTH
what 3 disorders of the adrenal cortex do we have to know?
hypoadrenocorticism (Addison’s)
hyperadrenocorticism (Cushing’s)
Adrenal neoplasia (of ferrets)
what disorder of the adrenal medulla do we have to know?
neoplasms –> pheochromocytoma
Hypoadrenocorticism and Hyperadrenocorticism are called ________ and ________ disease, respectfully.
Hypo: Addison’s
Hyper: Cushing’s
Cocaine makes you Hyper
(and then Addison’s is hypo lol)
What causes hypoadrenocorticism (Addison’s) in broad terms
adrenocortical insufficiency
Hypoadrenocorticism is most common in what species? how does this happen?
dogs
idiopathic adrenocortical atrophy
true or false: hypoadrenocorticsm affects only 1 layer of the adrenal cortex
False. it affects ANY OR ALL layers of the cortex
mineralocorticoids, glucocorticoids, sex hormones are all affected
Hypoadrenocorticism causes a mineralocorticoid _____. how does this manifest in terms of electrolytes?
deficiency
increased potassium, decreased sodium
Hypoadrenocorticism causes a glucocorticoid _____. how does the manifest?
deficiency
GI signs, hypoglycaemia, low cortisol and no response to ACTH stimulation test
how do you test for hypoadrenocorticism?
ACTH stimulation test
not cortisol measurements because cortisol fluctuates during the day so it isn’t as helpful
Hypoadrenocorticism causes ____ onset of vague clinical signs, like….
insidious
vomiting, diarrhea, weakness, lethargy, CV collapse
What is an Addisonian crisis? what is it caused by?
CV collapse
electrolyte imbalances
Idiopathic adrenocortical atrophy is characterized by what and in what signalment?
bilateral adrenal cortical atrophy in young adult dogs
what are the gross lesions of idiopathic adrenocortical atrophy?
none really, other than really small adrenals!
what is the mechanism of endocrine disease of hypoadrenocorticism?
primary hypo function
Left is a normal adrenal. R is from a dog with hx of vomiting, bloody diarrhea, lethargy, sudden death. what is the top ddx?
hypoadrenocorticism
Hyperadrenocorticism is a syndrome of ______ _____.
cortisol excess
what is one of the most common endrocinopathies of dogs?
hyperadrenocorticism
true or false: hyperadrenocorticism is common in cats
false! infrequent in cats
what are 3 pathogenic mechanisms of hyperadrenocorticism?
functional corticotroph (ACTH-secreting) pituitary adenoma (85-90%)
functional adrenal gland neoplasm (10-15%)
iatrogenic
what are the clinical signs and gross lesions of Hyperadrenocorticism?
increased appetite
muscular atrophy
cutaneous lesions
hepatomegaly
secondary infections
impaired wound healing
tell me 4 ways to tell there’s muscular atrophy in hyperadrenocorticism
pendulous abdomen (pot-bellied)
lordosis
trembling
straight-legged braced position
tell me at least 2 clinical signs that tell you that this dog is sick. what is he sick with?
pendulous abdomen, lordosis, alopecia, straight-legged braced position
hyperadrenocorticism
tell me 3 types of cutaneous lesions demonstrated with hyperadrenocorticism
alopecia
thin skin
calcification (calcinosis cutis)
what’s the lesion? what disease process probably caused this?
Calcinosis cutis
hyperadrenocorticism
why does hepatomegaly happen with hyperadrenocorticism?
steroid hepatopathy because of accumulation of glycogen in hepatocytes
adrenal cortical adenomas are most common in what signalment?
older dogs
True or false: adrenal cortical adenomas are often incidental, but can be functional
true
True or false: adrenal cortical carcinomas are more common than adenomas
false. they are less common than adenomas
adrenal cortical carcinomas are common in what signalment ?
older cattle and dogs
true or false: adrenal cortical carcinomas can be functional, are invasive, and can metastasize to liver, kidney, lymph nodes, and lungs
true
adrenal gland. what is the lesion?
adrenocortical adenoma
you can see it’s thinly encapsulated and contained in the cortex
true or false: adrenal disease in ferrets is pretty rare
false!!! extremely common!!
adrenal disease in ferrets occurs most commonly in what signalment?
females > males (2:1)
what is a common cause for adrenal disease in ferrets?
early gonadectomy
what is the spectrum of proliferative lesions that cause the same clinical syndrome in ferrets?
hyperplasia (45%)
carcinoma (45%)
adenoma (10%)
true or false: adrenal cortical neoplasms in ferrets can be unilateral or bilateral
true
with adrenal disease in ferrets, there is often concurrent _____.
insulinoma
which zone of the adrenal cortex is affected with adrenal disease in ferrets?
what does this mean?
zona reticularis
means that sex hormones are affected
tell me about the changes that occur because of adrenal disease in ferrets
increased estradiol-17B; normal cortisol
bilaterally symmetrical alopecia (both sexes)
enlarged vulva (female)
prostatic enlargement and urethral obstruction (males)
pancytopenia (both sexes)
this ferret has vulvar swelling and melena. what disease is high on ddx list?
adrenal disease (hyperplasia or carcinoma more likely than adenoma)
this ferret presents with bilaterally symmetrical alopecia and has pancytopenia. what is high on your ddx list?
adrenal disease (hyperplasia or carcinoma more likely than adenoma)
what is the most common tumor of the adrenal medulla?
pheochromocytoma
pheochromocytomas occur in what species?
dogs and bulls (C-cell tumor in thyroid)
true or false: there are only benign forms of pheochromocytomas
false. there are both malignant and benign forms
some pheochromocytomas are ____, meaning that they result in ____ catecholamine release, which results in _____.
functional
excessive
hypertension
this is an adrenal gland from a horse. what is it?
pheochromocytoma
dark red tumor - coming from medulla
