Learn: Pituitary Hormone Disorders: SIADH, Diabetes Insipidus, and GH Abnormalities | Quizlet

What does SIADH stand for?

Syndrome of Inappropriate Antidiuretic Hormone Secretion

What is the main problem in SIADH?

Too much ADH leads to too much water retention.

What is the serum sodium level in SIADH?

Decreased, leading to hyponatremia.

What is the urine osmolality in SIADH?

Increased.

What is the volume status in SIADH?

Euvolemia.

What is the diagnostic shortcut for SIADH?

LOW serum Na + LOW serum osmolality + HIGH urine osmolality.

What is Diabetes Insipidus (DI)?

A condition characterized by inadequate ADH action.

What are the two major types of Diabetes Insipidus?

Central DI and Nephrogenic DI.

What causes Central Diabetes Insipidus?

Decreased secretion of ADH from the pituitary due to head trauma or tumors.

What causes Nephrogenic Diabetes Insipidus?

Renal tubules unresponsive to ADH due to hypercalcemia, hypokalemia, or certain medications.

What is the urine osmolality in Diabetes Insipidus?

Decreased.

What is the serum sodium level in Diabetes Insipidus?

Increased, leading to hypernatremia.

What is the main symptom of Diabetes Insipidus?

Increased thirst (polydipsia) and urination (polyuria).

What is the effect of Growth Hormone hyposecretion in children?

Dwarfism.

What is the effect of Growth Hormone hypersecretion in children?

Gigantism.

What is acromegaly?

Overgrowth of skeleton and soft tissue in adults due to GH hypersecretion.

What hormone is consistently elevated in GH hypersecretion?

IGF-1.

What is the stalk effect?

Loss of hypothalamic communication leads to decreased anterior pituitary hormones but increased prolactin.

What is the relationship between dopamine and prolactin secretion?

Increased dopamine leads to decreased prolactin; decreased dopamine leads to increased prolactin.

What are the symptoms of hyperprolactinemia in females?

Amenorrhea and galactorrhea.

What are the symptoms of hyperprolactinemia in males?

Testicular atrophy, impotence, and gynecomastia.

What distinguishes Central DI from Nephrogenic DI?

Central DI responds to ADH; Nephrogenic DI does not.

What is the effect of increased GH in adults?

Acromegaly.

What is the effect of decreased GH in adults?

Relatively asymptomatic.

What is the lab finding for SIADH?

Hyponatremia with euvolemia and concentrated urine.

What is the lab finding for Diabetes Insipidus?

Hypernatremia and dilute urine.

What is a memory trick for Diabetes Insipidus?

DI = 'Dry Inside' due to large water loss.

What is the relationship between ADH action and urine concentration in SIADH?

Increased ADH action leads to concentrated urine.

What is the relationship between ADH action and urine concentration in Diabetes Insipidus?

Decreased ADH action leads to dilute urine.