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15 Cards in this Set
- Front
- Back
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Adrenal cortex secretes?
cortisol follows a blank pattern? Resting values: average free cortisol is? bound to? saliva? |
-aldosterone and cortisol
-diurnal: follows basal secretion -10%, biologically active -90% bound to CBG and albumin -CBG increase in high estrogen states: hyperthyroidism, diabetes, decreased in hypothyroidism and liver disease -no binding proteins in saliva, salivary levels = free cortisol |
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Circadian rhythm of cortisol:
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-parallels secretion of regulatory hormones from AP and hypothalamus
-cortisol levels are low to undectable during sleep -major secretion occurs during 6th-8th hr -gradual declines through the day w/ under night levels -high during surgery/ stress |
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Adrenal Cortex Stress
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-Cortisol secreted for:
-physical stress -immune response(cortisol is anti-inflammatory) -surgery -Abolished by high dose of glucocorticoid-->atrophy of adrenal cortex-->decreased hormone production |
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Glucocorticosteroids Regulation:
AP level Hypothalamus level |
-stimulated by low cortisol-->ACTH-->adrenal cortex to secrete cortisol
-stimulated by low cortisol, hypoglycemia, pyrogens, stress CRH-->AP to releace ACTH |
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Effects of Cortisol
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Intermediary metabolism:
-increase gluconeogensis -protein breakdown -lypolysis in peripheral, increase central adipose tissue Calcium homeostasis -decrease renal Ca reabsorption -decreased bone deposition Endocrine: -reduced pancreatic insulin secretion -increased adrenal catecolamine production(increase BP/HR) Anti-inflammatory properties -reduce monocyte/cytokines -impair cellular immunity Cardiovascualr: -increase contractility and adrenergic mediated vascular response Behavior |
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Mineralocorticosteroids:
controlled by? in plasma? responsible for? |
-aldosterone
-Renin-Angiotensin(acth, K, Na levels) -maintain normal K and Na concentrations -Na/Water retention, K depletion, increased PVR |
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Tests for Cortisol
plasma cortisol salivary cortisol Urinary free cortisol plasma ACTH suppresion |
-Plasma cortisol: free and bound forms
-useful after stim or suppresion -salivary cortisol: good for free cortisol elvels -late evening salivary levels for cushings -Urinary free cortisol: -indicate increase cortisol production -Plasma ACTH: adrenal(primary vs. pituitary Adrenal: normal feedback(cushings, low acth due to glucocorticoid excess) Pituitary: influence ACTH -measure feed back inhibiton via dexmethasone -good for hypersecretory state -Dexamethasone should suppress ACTH release, but if feedback is defective = cushings |
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cushing's syndrome vs. disease
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-Syndrome: glucocoticoid excess no matter what cause
disease: subtype primary caused by pituitary adenoma(ACTH receptor) |
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Cushings Syndrome classification
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-ACTH Dependent:
Excess ACTH via Pituitary adenoma, nonpituitary neoplasms(small cell carincoma of lung), CNS stimulation ACTH Indp. -excess from adrenal cortex(hyperplasia, adenoma, carcinoma), Iatrogenic excess(most common cause) |
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Cushings signs and symptoms
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-moon face, buffalo hump, trncal obesity
-increase body weight, edema, -hypertension -heart failure -osteoporosis -fatigue/weak -amenorrhea, hirsuitsim, hypertrophy clitoris -cutaneous striae, ecchymosis -hyperglycemia, polyuria, polydipsia -hypokalemia -personality changes |
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Cushing's tests
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-urinary free cortisol
-suppression test with dexamethasone -stimulated plasma ACTH production -helpful in differentiating adrenl, pituitary or ectopic causes -Evaluate adrenal gland size via CT/MRI -Pituitary is best visualized with MRI -pituitary adenoma |
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Cushing's Treatment
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Pituitary
-surgery -radiation -drugs Adrenal -surgery -block cortisol production Iatrogenic: taper |
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Hypofxn of Adrenal Cortex
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-Acute adrenal insufficiency
-Adrenal hemorrhage: sepsis(waterhouse friderichsen), anticoagulation therapy Adrenal crisis -stress imposed on chronic insufficiency -hyptotension, hypglycemia Chronic primary adrenal insufficiency(addison's) -autoimmune -granulomatous infection -HIV adrenalitis |
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Hypofxn Sx
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-weakness
-pigmentation -weight loss, anorexia, nausea, vomiting -hypotension, hypovolemia -salt craving -hyponatermia, hyperkalemia -hypoglycemia |
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Adrenal Insufficiency secondary to pituitary ACTH deficiency?
Diagnosis for primary adrenal insufficiency? Treatment |
-hypothalmic/pituitary tumors
-alodsterone not affected so less electrolyte volume issues -withdrawl of exogenous corticosteroid -response to ACTH infusion by plasma cortisol -replace corticosteroids -replenish volume with glucose and saline solutions |
