Hormones & Glands
This butterfly-shaped gland in the anterior neck produces T3 and T4.
What is the thyroid gland?
This is the most common cause of hypothyroidism, where the immune system attacks thyroid tissue.
What is Hashimoto's thyroiditis?
Type 1 diabetes results from autoimmune destruction of these pancreatic cells, causing absolute insulin deficiency.
What are beta cells?
SIADH causes this electrolyte abnormality due to excess water retention diluting the blood.
What is hyponatremia?
Thyroid storm is most commonly triggered by this type of event.
What is infection?
This synthetic thyroid hormone, taken on an empty stomach, is the standard lifelong replacement therapy for hypothyroidism.
What is levothyroxine (Synthroid)?
The posterior pituitary stores and releases this hormone, also called vasopressin, which promotes water reabsorption in the kidneys.
What is ADH (antidiuretic hormone)?
A patient with hyperthyroidism presents with weight loss, heat intolerance, tachycardia, and bulging eyes. This is the most common autoimmune cause.
What is Graves' disease?
This classic breathing pattern — deep and rapid — is a compensatory mechanism seen in DKA.
What is Kussmaul respirations?
In Diabetes Insipidus, urine specific gravity is characteristically below this value, indicating very dilute urine.
What is 1.005?
This drug class is given in thyroid storm to rapidly control tachycardia, tremor, and adrenergic symptoms while awaiting biochemical control.
What are beta-blockers (e.g., propranolol)?
In thyroid storm, iodine therapy (potassium iodide or Lugol's solution) must be given after this medication class to prevent worsening hormone release.
What are thionamides (antithyroid drugs — PTU or methimazole)?
This gland sits atop each kidney and is divided into the cortex and medulla, secreting cortisol, aldosterone, and epinephrine.
What are the adrenal glands?
In hypothyroidism, TSH is elevated. This is the expected finding for free T4.
What is low (decreased) free T4?
In DKA management, potassium replacement must be held until this condition is confirmed.
What is adequate urine output (and serum K⁺ level is not critically high / patient is not hyperkalemic)?
This type of DI occurs when the kidneys fail to respond to ADH. Lithium toxicity and hypercalcemia are common causes.
What is nephrogenic DI?
In DKA, the most common precipitating cause is this.
What is infection (or missed insulin)?
Corticosteroids used in thyroid storm serve this additional endocrine purpose beyond reducing T4-to-T3 conversion.
What is treating potential adrenal insufficiency?
These cells in the pancreatic islets of Langerhans produce insulin, while alpha cells produce this opposing hormone.
What is glucagon?
This life-threatening complication of untreated hypothyroidism presents with hypothermia, hypoventilation, and altered mental status.
What is myxedema coma?
This first-line oral medication for Type 2 diabetes decreases hepatic glucose output and improves insulin sensitivity without causing hypoglycemia.
What is metformin?
The cornerstone of SIADH management is this non-pharmacologic intervention, often restricted to 1 L/day.
What is fluid restriction?
This condition, a life-threatening muscle breakdown syndrome, presents with the classic triad of myalgia, muscle weakness, and dark tea-colored urine.
What is rhabdomyolysis?
This drug used for nephrogenic DI works by paradoxically reducing urine volume in patients through volume depletion and increased proximal tubule reabsorption.
What are thiazide diuretics?
The hypothalamic-pituitary-thyroid axis uses this type of regulatory mechanism, where elevated T3/T4 inhibits TRH and TSH release.
What is negative feedback?
This antithyroid drug is preferred in thyroid storm because it both blocks thyroid hormone synthesis AND inhibits peripheral conversion of T4 to T3.
What is propylthiouracil (PTU)?
In DKA, adipose tissue breaks down into free fatty acids, which the liver converts into these two ketone bodies responsible for metabolic acidosis.
What are acetoacetate and beta-hydroxybutyrate?
SIADH hypertonic saline must be corrected at a rate no faster than this many mEq/L in 24 hours to avoid this devastating neurological complication.
What is 8–10 mEq/L to avoid osmotic demyelination syndrome?
Fournier's gangrene is a rare but life-threatening adverse effect associated with this class of Type 2 diabetes medications.
What are SGLT2 inhibitors (e.g., canagliflozin, dapagliflozin, empagliflozin)?
These vasopressin receptor antagonists (vaptans) are used for chronic or refractory SIADH by blocking ADH action at the V2 receptor, causing aquaresis (free water excretion).
What are vaptans (e.g., tolvaptan, conivaptan)?
This malignancy is notorious for causing SIADH through ectopic ADH production, making it the most common cancer-related cause.
What is small cell lung carcinoma?
These two medications can both cause hypothyroidism as a side effect by suppressing thyroid hormone synthesis or release.
What are lithium and amiodarone?
Unlike DKA, this hyperglycemic emergency is associated with blood glucose levels often exceeding 600 mg/dL, extreme dehydration, no significant ketosis, and occurs more commonly in Type 2 diabetics.
What is HHS (Hyperosmolar Hyperglycemic State)?
This test is used to differentiate between central and nephrogenic DI: central DI will respond with urine concentration, while nephrogenic DI will not.
What is the DDAVP (desmopressin) challenge test?
In rhabdomyolysis, this specific protein released from destroyed muscle cells directly causes nephrotoxicity and tubular obstruction, leading to acute kidney injury.
What is myoglobin?
In thyroid storm management, this bile acid sequestrant is used to interrupt the enterohepatic recycling of thyroid hormone, reducing its reabsorption from the gut.
What is cholestyramine?
The pancreas is considered a dual-function gland. Name both its endocrine cell cluster and its three key hormones secreted from those cells.
What are the islets of Langerhans, secreting insulin, glucagon, and somatostatin?
A dangerous side effect of thionamide drugs (PTU and methimazole) that must be monitored, involving a critically low white blood cell count that increases infection risk.
What is agranulocytosis?
In DKA, insulin drives potassium into cells, but potassium replacement is critical. Name the two conditions that must be confirmed BEFORE starting potassium replacement in DKA management.
What is confirmed urine output (kidneys functioning) AND a serum potassium level that is not dangerously elevated (not severely hyperkalemic)?
SIADH causes euvolemic hyponatremia, but this is how volume expansion in SIADH leads to further sodium loss, despite the patient not appearing edematous.
What is stimulation of natriuretic peptides (ANP/BNP), which promote urinary sodium excretion (natriuresis), balancing the water gained while continuing to lower serum sodium?
Necrotizing fasciitis is primarily diagnosed through this method — not imaging — and this is the definitive diagnostic AND therapeutic step that must not be delayed.
What is emergent surgical exploration and debridement?
Fournier's gangrene requires triple empiric antibiotic therapy. Name the three classes of organisms that must be covered and an example drug combination used.
What are gram-positives (including MRSA), gram-negatives, and anaerobes — covered with a combination such as a carbapenem + vancomycin + clindamycin or metronidazole?