Review of Urine Concentration and Dilution Disorders

A series of vocabulary flashcards based on key concepts related to clinical disorders of urine concentration and dilution.

Vasopressin (AVP, ADH)

A hormone that regulates water balance, increases blood pressure, induces platelet aggregation, and is involved in thermoregulation.

Syndrome of Inappropriate ADH Secretion (SIADH)

A disorder characterized by the non-physiologic release of ADH leading to impaired water excretion and concentrated urine.

Hyponatremia

A condition defined as serum sodium levels less than 135 mEq/L, often due to a water imbalance.

Cerebral Adaptation

A defense mechanism against hyponatremia that helps decrease brain swelling through osmotic adjustments.

Water Deprivation Test

A diagnostic test that evaluates the body's response to decreased water intake and assesses ADH function.

Hypertonic saline

A treatment for severe hyponatremia, given to increase serum sodium levels.

Normal saline (0.9%)

Saline solution that is inappropriate for SIADH patients because it can worsen their condition by further diluting serum sodium.

Polyuria

Defined as urine output greater than 3 L per day, which may indicate underlying disorders.

Nephrogenic diabetes insipidus (DI)

A condition where the kidneys are resistant to the effects of ADH, leading to excessive urination.

Central diabetes insipidus (DI)

A deficiency of ADH secretion due to damage to the hypothalamus or pituitary gland.