Endocrine System Disorders and Stress

Vocabulary practice flashcards covering endocrine system disorders, hormone actions, diagnostic indicators, diabetic complications, and stress response mechanisms.

Steroid Hormones

Lipid-based hormones derived from cholesterol that cross the cell membrane and enter the nucleus directly to initiate messenger RNA transcription.

Nonsteroid Hormones

Hormones that require a secondary messenger system to activate the formation of messenger RNA in the cell nucleus.

Growth Hormone (GH)

A nonsteroid hormone secreted by the anterior pituitary gland (adenohypophysis) that stimulates protein synthesis throughout the body.

Adrenocorticotropic Hormone (ACTH)

An anterior pituitary hormone that stimulates the adrenal cortex to secrete primarily cortisol.

Thyroid-Stimulating Hormone (TSH)

An anterior pituitary hormone that stimulates the synthesis and release of thyroid hormones from the thyroid gland.

Antidiuretic Hormone (ADH)

A hormone synthesized in the hypothalamus and released by the posterior pituitary (neurohypophysis) that increases water reabsorption in the renal collecting ducts.

Insulin

An anabolic hormone produced by the beta cells of the pancreatic islets of Langerhans that promotes glucose transport into cells and lowers blood glucose levels.

Glucagon

A hormone produced by the alpha cells of the pancreatic islets of Langerhans that stimulates glycogenolysis and gluconeogenesis in the liver to raise blood glucose levels.

Parathyroid Hormone (PTH)

A hormone released in response to low blood calcium that increases serum calcium levels by stimulating bone demineralization and increasing calcium reabsorption in the kidneys and digestive tract.

Calcitonin

A hormone secreted by the thyroid gland in response to hypercalcemia that inhibits calcium release from bone to lower blood calcium levels.

Thyroxine ($T_4$) and Triiodothyronine ($T_3$)

Hormones synthesized from tyrosine and iodine in the thyroid gland that increase basal metabolic rate (BMR), regulate growth, and stimulate the sympathetic nervous system.

Aldosterone

A mineralocorticoid secreted by the zona glomerulosa of the adrenal cortex that increases sodium and water reabsorption and potassium excretion in the kidney tubules.

Cortisol

A glucocorticoid secreted by the zona fasciculata of the adrenal cortex that regulates carbohydrate metabolism, exerts anti-inflammatory and catabolic effects, and mediates the response to stress.

Epinephrine

A catecholamine released by chromaffin cells of the adrenal medulla during stress that causes bronchodilation, increased heart rate and force, skeletal muscle vasodilation, and visceral vasoconstriction.

Endemic Goiter

An enlargement of the thyroid gland occurring in regions with iodine-deficient soil and food, caused by excessive TSH secretion secondary to low $T_3$ and $T_4$ synthesis.

Goitrogens

Foods (such as cabbage and turnips) that contain chemicals blocking the synthesis of $T_3$ and $T_4$, leading to increased TSH secretion and thyroid hyperplasia.

Graves' Disease

An autoimmune form of hyperthyroidism where autoantibodies mimic TSH, leading to hypersecretion of $T_3$ and $T_4$, toxic goiter, and exophthalmos.

Exophthalmos

Protruding, staring eyes with decreased blink and movement caused by increased tissue mass in the orbit behind the eyeball, characteristic of Graves' disease.

Hashimoto's Thyroiditis

An autoimmune thyroid disorder characterized by autoantibody-mediated destruction of the thyroid gland, resulting in progressive hypothyroidism.

Myxedema

A severe, advanced complication of hypothyroidism in adults characterized by facial edema, a thickened tongue, low metabolic rate, and cold intolerance.

Cretinism

A congenital or early childhood form of hypothyroidism caused by thyroid aplasia or maternal iodine deficiency, leading to severe growth retardation, mental retardation, and a large thickened tongue.

Hypoparathyroidism

A deficit in PTH secretion leading to hypocalcemia, increased neuromuscular excitability, tetany, carpopedal spasms, and weak cardiac muscle contractions.

Hyperparathyroidism

Hypersecretion of PTH resulting in hypercalcemia, excessive bone demineralization (osteoporosis), forceful heart contractions, and formation of kidney stones.

Acromegaly

An adult hyperpituitary disorder caused by excess growth hormone secretion after epiphyseal plate fusion, resulting in broader and heavier bones, enlarged hands and feet, and soft tissue hypertrophy.

Diabetes Insipidus (DI)

A disorder caused by a deficit of ADH or renal insensitivity to ADH, manifesting as polyuria with dilute urine, polydipsia, hypernatremia, and dehydration.

Syndrome of Inappropriate ADH (SIADH)

A condition characterized by excessive ADH secretion, leading to inappropriate water retention, hypervolemia, dilutional hyponatremia, and highly concentrated urine.

Cushing's Syndrome

A disorder caused by hypersecretion of cortisol or prolonged glucocorticoid therapy, characterized by moon face, buffalo hump, truncal obesity, purple striae, hyperglycemia, and suppressed immunity.

Addison's Disease

Adrenocortical insufficiency involving a destruction of the adrenal cortex and deficit of glucocorticoids, mineralocorticoids, and androgens; results in hypoglycemia, hypotension, hyperkalemia, and skin hyperpigmentation.

Pheochromocytoma

A benign tumor of the chromaffin cells in the adrenal medulla that secretes excessive epinephrine and norepinephrine, causing severe episodic hypertension, headaches, palpitations, and anxiety.

Type 1 Diabetes Mellitus

An autoimmune disease resulting in the destruction of pancreatic beta cells and absolute deficiency of insulin, requiring exogenous insulin replacement.

Type 2 Diabetes Mellitus

A metabolic disorder characterized by peripheral insulin resistance and relative insulin deficiency, strongly linked to obesity and managed primarily with lifestyle modification and oral hypoglycemics.

Glucosuria

The presence of excess glucose in the urine that occurs when blood glucose levels exceed the renal reabsorption threshold.

Polyuria

The production and excretion of abnormally large volumes of urine, often caused by osmotic diuresis secondary to glucosuria.

Polydipsia

Excessive thirst triggered by hypothalamic osmoreceptors in response to intracellular dehydration and hyperosmolar plasma.

Polyphagia

Excessive hunger caused by cellular energy deprivation in the presence of insulin deficit.

Diabetic Ketoacidosis (DKA)

An acute metabolic emergency in Type 1 diabetes caused by severe insulin deficiency, leading to lipolysis, ketoacid accumulation, metabolic acidosis, Kussmaul respirations, and acetone breath.

Hyperglycemic Hyperosmolar Nonketotic Syndrome (HHNK)

An acute complication of Type 2 diabetes characterized by extreme hyperglycemia, high serum osmolarity, and severe diuresis leading to dehydration without significant ketoacidosis.

Diabetic Macroangiopathy

A chronic vascular complication of diabetes affecting large arteries, accelerating atherosclerosis and predisposing patients to myocardial infarction, stroke, and peripheral vascular disease.

Diabetic Microangiopathy

A chronic diabetic complication characterized by thickening and weakening of capillary basement membranes, causing tissue ischemia, retinopathy, microaneurysms, and nephropathy.