Endocrine 2 Flashcards
What is a normal ratio of the different parts of the adrenal gland?
A ratio of 1:2:1 cortical:medullary:cortical
What is the outer zone of the adrenal cortex called? What is its function?
Zona glomerulosa. It produces mineralocorticoids such as aldosterone.
What is the middle zone of the adrenal gland called? What is its function?
Zona fasiculata. It produces glucocorticoids such as cortisol.
What is the inner zone of the adrenal cortex called? What is its function?
Zona reticularis. It produces sex hormones such as progesterone, estrogen, and androgens as well as some cortisol (but not as much as zona fasiculata).
What are the three disorders of the adrenal cortex?
- Hypoadrenocorticism (Addison’s Disease)
- Hyperadrenocorticism (Cushing’s Disease)
- Adrenal neoplasia of ferrets
What is the main disorder of the adrenal medulla?
Neoplasia (pheochromocytoma).
What is the main cause of hypoadrenocorticism in dogs?
Idiopathic immune-mediated adrenocortical atrophy.
Which layers of the adrenal cortex does hypoadrenocorticism affect?
Any or all layers, so mineralocorticoids, glucocorticoids, and sex hormones are affected.
Hypoadrenocorticism mostly causes a _________________ deficiency.
Mineralocorticoid.
What electrolyte changes will you see on a chemistry in a dog with hypoadrenocorticism?
- Severe hyperkalemia
- Severe hyponatremia and hypochloremia
This is an Addisonian crisis.
Cortisol is ___________ sparing.
Glucose.
What would you expect to see on an ACTH stimulation test with hypoadrenocorticism?
It will have no response to ACTH (cortisol does not increase as it should normally).
Which species is hypoadrenocorticism most common in?
Dogs.
What gross lesions do we see with hypoadrenocorticism?
None other than really small adrenal glands.
What mechanism of endocrine disease accounts for immune-mediated hypoadrenocorticism?
Primary hypofunction.
What are the three pathogenic mechanisms of hyperadrenocorticism?
- Functional corticotroph (ACTH-secreting) pituitary adenoma (85-90%)
- Functional adrenal gland neoplasm (10-15%)
- Iatrogenic.
What do you see grossly with a functional corticotroph pituitary adenoma?
Bilateral adrenal cortical hypertrophy/hyperplasia.
What do you see grossly with a functional adrenal gland neoplasm?
Unilateral adrenal cortical neoplasm with contralateral adrenal cortical atrophy (atrophies because there’s no work for it to do now).
What do you see grossly with an iatrogenic-induced hyperadrenocorticism?
Bilateral adrenal cortical atrophy.
What are the symptoms of Cushing’s disease in dogs?
- Increased appetite
- Muscle atrophy (ex. pot-bellied appearance, lordosis)
- Cutaneous lesions (ex. alopecia, calcinosis cutis, thin skin).
What gross extra-adrenal lesions do you see with Cushing’s disease?
Hepatomegaly (steroid hepatopathy) and impaired wound healing.
What does an adrenal cortical adenoma look like grossly?
It is yellow, thinly encapsulated, and contained within the adrenal cortex.
What does an adrenal cortical carcinoma look like grossly?
It causes a complete loss of architecture so the adrenal gland will be mostly replaced by the carcinoma that is twice the size of the kidney. It doesn’t even look like an adrenal gland!
Which is more common in dogs, adrenal cortical adenomas or adrenal cortical carcinomas?
Adrenal cortical adenomas.
What are four differences between adrenal cortical adenomas and adrenal cortical carcinomas?
- Adrenal cortical carcinomas tend to be larger.
- Adrenal cortical carcinomas are invasive and metastasize to the liver, kidneys, nodes, and lungs.
- Adrenal cortical carcinomas are less common than adenomas.
- Adrenal cortical adenomas are often incidental.
What is one similarity between adrenal cortical adenomas and adrenal cortical carcinomas?
Both can be functional.
In which two species are pheochromocytomas most common in?
Dogs and cattle.
What is required by the thyroid gland to make T3 and T4?
Iodine.
What is adrenal disease in ferrets?
This is sort of like Cushing’s in other animals, but not quite. The diseased glands do not produce excessive cortisol levels, but instead produce excessive sex-related hormones like estradiol, androstenedione, and progesterone (due to target of the zona reticularis).
True or False: Adrenal disease in ferrets is more common in females than males.
True
What are the four clinical signs of adrenal disease in ferrets? Hint: Are there any sex differences?
- Bilaterally symmetrical alopecia (both sexes)
- Pancytopenia (both sexes)
- Enlarged vulva (females)
- Prostatic enlargement and urethral obstruction (males).
