Kapitel 120 – Adrenal glands Flashcards
Name the layer and function of the adrenal cortex
a. outer zona glomerulosa – secretes mineralocorticoids
b. central zona fasciculata and inner zona reticularis – secrete glucocorticoids and sex steroids
what is the primary function of glucocorticoids?
regulation of metabolism, particularly by stimulation of hepatic gluconeogenesis
what is the major function of the mineralocorticoid aldosterone?
electrolyte balance and blood pressure homeostasis
what is the function of epinephrine on metabolism?
a. increases blood glucose concentrations
b. stimulates glycogenolysis in skeletal muscle
c. inhibits insulin secretion (via alpha-2 receptors)
d. stimulates pancreatic glucagon secretion to increase blood glucose concentrations
e. and promotes lipolysis to increase free fatty acid concentrations in the blood.
–> All this as a response to hypoglucemia
What is the effect of epinephrine on the cardiovascular system?
a. increase the force of cardiac contraction
b. increase heart rate (by shortening the duration of diastolic depolarization)
what is the function of norehinephrine on the cardiovascular system?
causes generalized vasoconstriction through stimulation of alpha receptors, resulting in an increase in vascular resistance and systolic blood pressure
How is the diagnosis of an adrenal lass made on ultrasound?
a. when the maximum width of the adrenal gland exceeds 1.5 cm
b. the gland loses its typical “kidney-bean” shape
c. and the gland is asymmetric in shape and size compared with the contralateral adrenal gland
what is the positive and negative predictive value in detecting vascular invasion of an adrenal mass on CT?
a. Positive predictive value: 100 %
b.Negative: 90%
Can you determine if hyperadrenocorticism is pituitary or adrenal dependent based on low-dose dexamethasone test?
No. It can give you a suspicion if the serum cortisol is not suppressing at neither 4 or 8 h it is likely to be adrenal dependent but 40% of pituitary dependent also fail to suppress.
What is some peri-operative concerns in animals with cortisol secreting adrenal tumors?
a. Thromboembolism (dog)
b. Fragile atrophic skin (cat)
c. Postoperative hypoadrenocorticism
d. Impaired wound healing
What is some peri-operative concerns in animals with Aldosteron secreting adrenal tumors?
a. Systemic hypertension
b. Severe hypokalemia
What is some peri-operative concerns in animals with epinephrine secreting adrenal tumors?
a. Severe paroxysmal hypertension
b. Severe tachycardia and tachyarrhythmias
What is the most common clinical signs if pheochromocytoma?
Generalized weakness and episodic collapse
What are important clues to diagnosis of a pheochromocytoma?
ultrasonographic identification of an adrenal mass with a normal-sized contralateral adrenal gland and normal adrenal function on screening tests for hyperadrenocorticism
What are the surgical approaches to the adrenal glands?
a. Ventral approach
b. Flank approach
c. Laparoscopic
