Term
List the three layers of the adrenal cortex: |
|
Definition
Zona glomerulosa Zona fasciculata Zona reticularis |
|
|
Term
Aldosterone is secreted in response to what factors? |
|
Definition
Elevated potasium--even 1% increase in potassium
Hypotension, decreased blood volume, decreased sodium |
|
|
Term
Aldosterone is mediated by _________________, which are potent vasoconstrictors. |
|
Definition
|
|
Term
What is the biological half life of aldosterone? |
|
Definition
|
|
Term
Aldosterone functions in renal sodium _____________ and renal potassium ______________. The end result is that blood potassium levels _______________. |
|
Definition
Conservation Excretion Decrease |
|
|
Term
Anticipate the relative values of sodium and potassium for hypoaldosteronism and hyperaldosteronism: |
|
Definition
Hypoaldosteronism: K increases, Na decreases
Hyperaldosteronism: K decreases, Na increases |
|
|
Term
What are the functions of glucocorticoids on overall metabolism? |
|
Definition
Increase gluconeogenesis/glycogenolysis
Increase fatty acid mobilization
Decrease protein synthesis |
|
|
Term
GC have the opposite effects of _________. |
|
Definition
|
|
Term
Describe the functions of GC on the central nervous system: |
|
Definition
Stimulate appetite center
Sensory acuity |
|
|
Term
Describe the functions of GC on the bone/skeletal system: |
|
Definition
Decreases calcium availability by opposing the action of Vitamin D in the GI tract, inducing calciuresis, and increasing the rate of bone resorption
High levels of cortisol--osteoporosis |
|
|
Term
Describe the functions of GC on the vasculature: |
|
Definition
Maintain normal BP and volume, myocardial performance, role in vascular constriction, decrease the release of vasodilators, decrease vascular permeability |
|
|
Term
Describe the function of GC on the GI tract: |
|
Definition
Maintain normal perfusion and hydrostatic pressure
Role in normal motility |
|
|
Term
Describe the functions of GC in the inflammatory/immune system: |
|
Definition
Stress response/stress leukogram |
|
|
Term
GC excess = _______________. |
|
Definition
|
|
Term
GC deficiency = _________________. |
|
Definition
|
|
Term
What clinical disease is manifested by hypertension, diarrhea, stress leukogram, and hyperglycemia? |
|
Definition
|
|
Term
What clinical disease is manifested by hypotension, ileus, lack of stress leukogram in sick animals, and hypoglycemia? |
|
Definition
|
|
Term
Primary Addison's is due to a loss of adrenal cortical cells and requires a loss of _______ before clinical signs are noted. |
|
Definition
|
|
Term
Secondary Addison's is due to what? |
|
Definition
Lack of ACTH stimulation to the adrenal gland |
|
|
Term
What are the etiologies of primary Addison's? |
|
Definition
Immune-mediated (lymphoplasmacytic)
Idiopathic atrophy/fibrosis
Metastatic replacement (lymphoma)
Cytotoxic drugs
Granulomatous disease (blasto, histo)
Hemorrhagic infarction
Trauma
Surgical removal
Excess GC supplementation |
|
|
Term
What is the general trend in signalment for Addison's? |
|
Definition
Female Large breed Younger at time of diagnosis |
|
|
Term
The female: male ratio of patients with Addison's is _____________, patients are ________ years old at diagnosis, and the most common breed diagnosed is _____________. |
|
Definition
70:30 2-7 years old Mixed breed |
|
|
Term
What canine breeds have a genetic predisposition to Addison's? |
|
Definition
Standard Poodle Portuguese Water Dog Bearded Collie Laborador Retriever Leonberger Nova Scotia Duck Tolling Retriever |
|
|
Term
T/F: there are pathognomonic signs for Addison's disease. |
|
Definition
|
|
Term
What are the most common signs associated with Addison's disease? |
|
Definition
Poor appetite Lethargy/depression Weight loss/poor body condition Vomiting/Regurgitation Weakness Diarrhea Polyuria |
|
|
Term
What are the physical exam findings for Addison's disease? |
|
Definition
Severe dehydration Bradycardia Poor peripheral pulse quality Melena/hematochezia Hypothermia Abdominal pain |
|
|
Term
What are some clues that point to Addison's disease on a CBC/Chem/UA? |
|
Definition
Lack of stress leukogram Eosinophilia/lymphocytosis Hypoglycemia
Azotemia--BUN may be elevated more than creatinine
Isosthenuria d/t increased renal sodium loss--may look like renal failure |
|
|
Term
What are some reasons that an azotemic Addisonian would have a higher BUN than creatinine? |
|
Definition
Pre-renal (dehydration?) GI hemorrhage |
|
|
Term
What ECG abnormalities are often noted in Addisonian patients? |
|
Definition
Initial change: peaked T wave and bradycardia
Severe hyperkalemia: asystole/ventricular fibrillation |
|
|
Term
What is the test of choice to diagnose Addison's disease? |
|
Definition
ACTH stimulation test
Take baseline cortisol-->inject ACTH compound-->measure 1 hour post cortisol |
|
|
Term
What are the typical results from an ACTH test positive for Addison's? |
|
Definition
|
|
Term
What is another, newer diagnostic option for diagnosing Addison's in a dog? |
|
Definition
|
|
Term
T/F: exogenous GC administration can interfere with basal cortisol or ACTH stim testing. |
|
Definition
|
|
Term
What is the dose of GC that can be administered to treat Addison's? |
|
Definition
Phydiologic dose: 0.25-0.5 mg/kg/day PO |
|
|
Term
Mineralocorticoids can be administered to Addison's patients. The two options are ________________, administered orally, and ___________________, which is injectable. Of these two drugs, which one requires glucocorticoid supplementation? |
|
Definition
Florinef Percorten
Both may require GC supplementation, although Florinef has some GC activity so only about 50% of patients require GC supplementation. Percorten, houwever, has solely MC activity. |
|
|
Term
What is the prognosis of animals with Addison's if they have committed owners? |
|
Definition
|
|
Term
The typical Addisonian is ______________ and _________________ deficient, while the atypical Addisonian is __________________ deficient only, __________________ levels and functions are maintained, and electrolytes are _______________. |
|
Definition
Glucocorticoid Mineralocorticoid Glucocorticoid Mineralocorticoid Normal |
|
|
Term
What are the clinical signs of an Atypical Addisonian? |
|
Definition
Due to GC deficiency: neuropathy, myopathy, GI, appetite |
|
|
Term
How can atypical Addison's be diagnosed? |
|
Definition
ACTH stim test
Basal cortisol levels |
|
|
Term
T/F: with atypical Addison's, therapy includes replacing both GC and MC. |
|
Definition
|
|
Term
An Addisonian crisis is the result of what four factors? |
|
Definition
Profound dehydration Hypoglycemia Hyperkalemia Hyponatremia |
|
|
Term
The most life threatening component of an Addisonian crisis is ________________________, so the most important part of therapy is ____________________. |
|
Definition
Vascular collapse and shock IV fluid replacement |
|
|
Term
T/F: cats are much more likely to get Addison's than dogs. |
|
Definition
|
|
Term
What are the etiologies of secondary Addison's in cats? |
|
Definition
Adrenal involvement of lymphoma Megestrol acetate therapy GC therapy |
|
|
Term
On laboratory evaluation, cats with Addison's will show what? |
|
Definition
Hyponatremia Hyperkalemia (less severe than dogs) Azotemia Isosthenuria to mild hypersthenuria Microcardia Less severe ECG abnormalities |
|
|
Term
What test is the gold standard for diagnosing cats with Addison's disease? |
|
Definition
|
|
Term
T/F: the cat has a slower response to therapy than the dog with Addison's. |
|
Definition
|
|