Endocrine System Quiz: Hormones & Conditions

Specific Gravity

• Indicator of urine concentration, relating the density of urine to that of water.
• A high specific gravity suggests concentrated urine; a low value indicates diluted urine.
• Normal range typically falls between 1.005 and 1.030.
• Useful for assessing kidney concentration abilities and body hydration status.

SIADH (Syndrome of Inappropriate Antidiuretic Hormone)

• Condition characterized by excessive secretion of Antidiuretic Hormone (ADH).
• Potential causes include dysfunctions of the hypothalamus or pituitary gland, or tumors.
• Symptoms may involve water intoxication and hyponatremia.
• Management includes fluid restriction to prevent fluid overload.
• Treatment often involves administering 3% hypertonic saline to correct sodium imbalance.

Adrenal Cortex Hormones

Mineralcorticoid: Aldosterone

• Component of the Renin-Angiotensin-Aldosterone System (RAAS).
• Primary function is to promote sodium reabsorption in kidneys, increasing sodium levels and promoting potassium excretion.

Glucocorticoid: Cortisol

• Enhances glucose availability during stress, whether emotional or physical.
• Often referred to as the "stress hormone," providing a quick energy source.

Spironolactone

• Medication that blocks aldosterone receptors in the nephron's distal convoluted tubules.
• Results in increased sodium excretion in urine and decreased potassium loss (potassium-sparing effect).
• Anti-androgen effects lead to feminization; doses vary based on treatment goals (50-100 mg for hypertension, 200-400 mg for anti-androgen effects).
• Can cause gynecomastia in individuals assigned male at birth (AMAB).

ADH Effects on Urine Output

• High ADH leads to fluid retention, reduced urine output, and potential fluid overload, indicated by SIADH.
• Low ADH results in increased urine output (diuresis) and dehydration, associated with Diabetes Insipidus.
• Increased urine output and dehydration in Diabetes Insipidus correlates with elevated sodium levels due to fluid loss, leading to hypernatremia.

Treatment Approaches

• SIADH treatment includes administering 3% Sodium Chloride to manage sodium imbalance.
• For Diabetes Insipidus, desmopressin (DDAVP) is used to enhance water retention by mimicking ADH effects at kidney receptors.
• Desmopressin typically has fewer cardiovascular side effects due to its weak vasopressin action.

Specific Gravity

• Indicator of urine concentration, representing the density of urine compared to water.
• High specific gravity indicates concentrated urine; low specific gravity indicates diluted urine.
• Normal range is between 1.005 and 1.030.
• Useful for assessing kidney concentrating ability and overall hydration status.

SIADH (Syndrome of Inappropriate Antidiuretic Hormone)

• Characterized by excessive secretion of Antidiuretic Hormone (ADH).
• Causes may include hypothalamic or pituitary gland issues, or tumors.
• Symptoms include water intoxication and hyponatremia, potentially leading to severe side effects similar to desmopressin.
• Treatment involves fluid restriction to manage fluid overload and administering hypertonic saline (3% NaCl) to correct sodium imbalance.

Hormones of the Adrenal Cortex

Mineralcorticoid: Aldosterone

• Part of the Renin-Angiotensin-Aldosterone System (RAAS).
• Functions to promote sodium reabsorption in kidneys, raising sodium levels and facilitating potassium excretion.

Glucocorticoid: Cortisol

• Increases glucose availability in response to stress (emotional or physical).
• Often referred to as the "stress hormone," aiding in providing quick energy.

Spironolactone (Aldactone)

• Mechanism blocks aldosterone receptors in nephron tubules, leading to increased sodium and water loss, and decreased potassium loss (potassium-sparing).
• Dosage: 50-100 mg for hypertension; 200-400 mg for anti-androgen effects.
• Anti-androgen effects may lead to feminization in individuals assigned male at birth (AMAB), such as gynecomastia.

Diabetes Insipidus (DI)

• Caused by low ADH levels, leading to excessive urine output and dehydration.
• Urine output increases (more diuresis) alongside decreased water retention.
• Sodium levels elevate due to dehydration, which can cause hypernatremia.

Desmopressin Acetate (DDAVP)

• Synthetic form of ADH designed to bind to kidney receptors, enhancing water reabsorption.
• Administration routes: nasal spray, subcutaneous (SQ), intravenous (IV), and sublingual.
• Indicators of effectiveness include decreased polyuria, reduced thirst, and increased urine specific gravity.

Side Effects of Desmopressin

• Major risks include water intoxication and hyponatremia, which can alter mental status and lead to seizures.
• Cardiovascular side effects are generally less concerning due to desmopressin's weak vasopressin effect.
• Monitoring is essential for headaches, nausea, confusion, and seizures.
• Patients should manage fluid intake, undergo regular electrolyte and kidney function tests, and adhere to medication instructions.

Test your knowledge on specific gravity, SIADH, and adrenal cortex hormones. This quiz covers key concepts including urine concentration, hormonal functions, and associated conditions. Assess your understanding of kidney functions and fluid management related to endocrine disorders.