4. Diseases of the Posterior Pituitary

A set of vocabulary flashcards covering key concepts related to diseases of the posterior pituitary, focusing on diabetes insipidus, the syndrome of inappropriate secretion, and related pathophysiology.

Diabetes Insipidus (DI)

A disorder characterized by excessive urination and thirst due to a deficiency in antidiuretic hormone (ADH) action.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)

A condition resulting from excessive secretion of ADH, causing water retention and hyponatremia.

Polyuria

Excessive urination, defined as urine output exceeding 3 L/day in adults.

Polydipsia

Excessive thirst or excessive fluid intake.

Desmopressin

A synthetic analogue of vasopressin used to treat diabetes insipidus.

Vasopressin

Also known as antidiuretic hormone (ADH), it regulates water retention in the kidneys.

Plasma Osmolality

A measure of the concentration of solutes in the blood, typically expressed in mOsm/kg.

Urine Specific Gravity

A measure of urine concentration that compares urine density to pure water.

Hypothalamic Diabetes Insipidus

Diabetes insipidus caused by decreased vasopressin synthesis or secretion from the hypothalamus.

Nephrogenic Diabetes Insipidus (NDI)

A type of diabetes insipidus caused by the kidneys' resistance to vasopressin.

Water Deprivation Test

A test used to diagnose diabetes insipidus by evaluating the kidney's ability to concentrate urine.

Idiopathic DI

Diabetes insipidus without an identifiable cause.

Gestational DI

A rare form of diabetes insipidus that occurs during pregnancy.

Lithium

A medication that can cause nephrogenic diabetes insipidus in long-term use.

Hypernatremia

A high concentration of sodium in the blood, often occurring due to dehydration.

Cranial Trauma

Injury to the skull or brain that can lead to diabetes insipidus.

Thrill

A palpable vibration, usually associated with turbulent blood flow in large vessels.

Pituitary Stalk

A structure that connects the pituitary gland to the hypothalamus.

Atrial Natriuretic Hormone (ANP)

A hormone that promotes sodium excretion and regulates extracellular fluid volume.

Hyponatremia

A low sodium concentration in the blood, often defined as <135 mEq/L.

Ectopic ADH Secretion

Production of ADH from a non-pituitary source, often due to malignancy.

Vasopressin Escape

A phenomenon where the kidneys increase water excretion despite high levels of ADH.

Neurohypophysis

The posterior part of the pituitary gland that stores and releases vasopressin.

Craniopharyngioma

A rare brain tumor that can cause endocrine dysfunction due to its location near the pituitary.

Adamantinomatous CPH

A subtype of craniopharyngioma mostly found in children, often presenting with cystic features.

Papillary CPH

A subtype of craniopharyngioma found in adults, characterized by solid growth and no cystic changes.

Bitemporal Hemianopsia

Loss of vision in the outer visual fields, often due to pressure on the optic chiasm.

Calcification

The accumulation of calcium salts in tissue, often seen in certain types of tumors.

MRI (Magnetic Resonance Imaging)

An imaging technique that uses magnetic fields and radio waves to create detailed images of the body.

CT (Computed Tomography)

An imaging method that utilizes X-rays to create cross-sectional images of the body.

Polydipsia Types

Divided into psychogenic and dipsogenic; characterized by excessive water intake.

Diuretic Effect

The increased production of urine by the kidneys.

Obstructive Hydrocephalus

A condition where increased cerebrospinal fluid (CSF) pressure is caused by blockage.

Hydration Status

A measure of body fluid balance, important in conditions such as diabetes insipidus.

Hormonal Therapy

Treatment involving hormones or hormone-related medications to manage endocrine disorders.

Pathologic Basis of Disease

A reference textbook outlining the mechanisms and processes underlying diseases.

Clinical Presentation

The signs and symptoms a patient exhibits when presenting with a medical condition.

Treatment Principles

The foundational approaches or methodologies used in managing a medical condition.

Neural Mechanisms of Thirst

Physiological processes that trigger thirst in response to body hydration levels.

Nephron

The functional unit of the kidney responsible for filtering blood and producing urine.

Syndrome Definition in Medicine

A specific set of medical signs and symptoms grouped together to identify a condition.