4. Adrenal gland Flashcards
responsible for
A) minute-to-minute regulation of blood pressure
B) blood volume
C) vascular tone
Adrenal gland
adrenal cortex zona:
mineralocorticoid hormones
zona glomerulosa
adrenal cortex zona:
glucocorticoid hormones
zona fasciculata
adrenal cortex zona:
sex steroids
zona reticularis
Identify the disease.
lack of mineralocorticoids secretion may result in?
Clinical signs
- lethal retention of potassium
- loss of sodium
Addison disease
suppress inflammatory and immunologic responses, thereby reducing associated tissue destruction and fibroplasia
glucocorticoid hormones
any cause of elevated cortisol concentrations
Cushing syndrome
Other term for cushing syndrome
HYPERadrenocorticism
most common form of hyperadrenocorticism and accounts for 80%-85% of reported cases
Pituitary-dependent hyperadrenocorticism (PDH)
a unilateral or bilateral adrenal tumor secretes cortisol
accounts for 10%-15% of cases
Adrenal-dependent hyperadrenocorticism
less common causes of Cushing syndrome
- ectopic secretion of ACTH
- episodic Cushing disease
- meal induced
- “atypical” manifestations
Clinical signs:
• polyuria and polydipsia
• weight gain
• endocrine alopecia
• muscle atrophy
• a “pot-bellied” appearance
Cushing syndrome
Laboratory abnormalities :
• elevations in serum alkaline phosphatase
• decreased urine concentrating ability
• diabetes mellitus and/or insulin resistance can be seen in as many as 15% of canine cases
Cushing syndrome
Diagnosis:
Initial steps
• accurate history
• thorough physical examination
• screening laboratory tests (CBC, chemistry panel, urinalysis)
specific adrenal function tests are performed to confirm hyperadrenocorticism and differentiate between the various causes
Cushing syndrome
results from the lack of glucocorticoids, mineralocorticoids, or both
• Isolated aldosterone insufficiency appears to be very rare
• isolated glucocorticoid insufficiency is likely underdiagnosed given the lack of electrolyte abnormalities
Addison disease
other term for Addison disease
HYPOadrenocorticism
Clinical signs:
• often vague
• may wax and wane over time
• rarely pathognomonic
• may be present for days, weeks, or months before diagnosis
Addison disease
Diagnosis
- hyponatremia
- hyperkalemia
- a sodium:potassium ratio of < 25:1
- azotemia
- mild acidosis
- normocytic, normochromic anemia
evaluation of adrenal function
Addison disease
disease to test in ACTH stimulation test
Addison disease
should always initially be performed in acutely ill patients or when the resting cortisol concentration is < 2 mcg/dL
ACTH stimulation test
Differential Diagnosis:
• primary GI disease (especially whipworm infection)
• renal failure
• acute pancreatitis
• toxin ingestion
Addison disease
central portion of the adrenal gland
primary source of epinephrine & norepinephrine
plays a role in stress / hypoglycemia
adrenal medulla
