Overview
This lecture covers adrenal gland hormones, related disorders (such as Addison’s disease and Cushing’s syndrome), their causes, symptoms, treatments, and key distinctions between similar conditions.
Adrenal Gland Structure & Hormones
- The adrenal glands sit on top of each kidney and have two parts: the medulla (inner) and cortex (outer).
- The adrenal medulla produces catecholamines (epinephrine/adrenaline and norepinephrine) for emergency "fight-or-flight" responses.
- The adrenal cortex produces aldosterone (salt hormone), cortisol (sugar/stress hormone), and in females, sex hormones (androgens).
- Aldosterone regulates sodium and water reabsorption; cortisol increases blood glucose during stress.
- The adrenal glands are controlled by the pituitary gland.
Disorders of the Adrenal Medulla
- Pheochromocytoma is a tumor of the adrenal medulla that overproduces catecholamines.
- Symptoms include severe hypertension, tachycardia, sweating, headache, flushing, anxiety, and hypoglycemia.
- Diagnosis is through imaging (CT or MRI).
- Treatment is surgical removal of the adrenal gland; pre-op management focuses on controlling blood pressure with medications.
- Avoid palpating the tumor to prevent catecholamine surges.
Adrenocortical Insufficiency (Addison’s Disease)
- Addison’s disease results from insufficient production of aldosterone and cortisol due to adrenal cortex or pituitary dysfunction.
- Symptoms: low blood pressure, low sodium, high potassium, low blood sugar, weakness, weight loss, nausea, vomiting.
- Causes include pituitary tumors, adrenal damage, sudden steroid withdrawal, or certain drugs.
- Treatment includes steroid replacement (hydrocortisone), isotonic fluids with dextrose for crisis, potassium-lowering interventions, and patient education.
- Addisonian crisis is a severe life-threatening exacerbation, often triggered by sudden withdrawal or stress.
Cushing’s Syndrome & Disease
- Cushing’s syndrome: excess cortisol and aldosterone from long-term steroid use.
- Symptoms: hypertension, hypernatremia, hyperglycemia, hypokalemia, moon face, buffalo hump, central obesity, thin skin, striae, delayed healing, mood swings.
- Cushing’s disease: excess hormone due to pituitary/adrenal cortex tumors.
- Cushing’s syndrome is managed by reducing steroid dose; Cushing’s disease requires tumor removal (adrenalectomy or hypophysectomy).
Hypophysectomy (Pituitary Gland Removal)
- Performed via a transsphenoidal (through the nose and mouth) approach.
- Post-op care: nasal packing, mustache dressing, no tooth brushing (rinses only), avoid raising intracranial pressure (no coughing, sneezing, bending, or heavy lifting).
- Monitor for CSF leaks using the halo sign on gauze.
Key Terms & Definitions
- Aldosterone — hormone regulating sodium and water retention.
- Cortisol — stress hormone raising blood glucose.
- Catecholamines — adrenaline and noradrenaline, mediate fight-or-flight.
- Pheochromocytoma — catecholamine-secreting tumor of adrenal medulla.
- Addison’s disease — adrenal cortex insufficiency (low cortisol/aldosterone).
- Addisonian crisis — acute, life-threatening adrenal insufficiency.
- Cushing’s syndrome — excess cortisol/aldosterone from long-term steroid use.
- Cushing’s disease — excess hormone from pituitary/adrenal cortex tumor.
- Hypophysectomy — surgical removal of the pituitary gland.
- Transsphenoidal approach — surgery through the nose/mouth to access the pituitary.
Action Items / Next Steps
- Review Addison’s disease and Cushing’s syndrome clinical features and management.
- Study pre- and post-op care for hypophysectomy.
- Complete assigned reading on adrenal and pituitary gland disorders.