Endocrine Disease: Parathyroid, Pancreas, Adrenal Glands, and MEN Syndromes

Vocabulary practice flashcards reviewing parathyroid physiology, pancreatic function, diabetes mellitus, adrenal disorders, and Multiple Endocrine Neoplasia syndromes based on lecture notes.

Parathyroid Glands

Four small endocrine glands located on the posterior surface of the thyroid gland, primarily composed of chief cells and oxyphil cells.

Chief Cells

The primary cells of the parathyroid glands responsible for secreting parathyroid hormone (PTH) to regulate blood calcium levels.

Oxyphil Cells

Cells located in the parathyroid glands with an unknown function.

Parathyroid Hormone (PTH)

A hormone released in response to decreased blood calcium ($\text{Ca}^{2+}$) without hypothalamic or pituitary stimulation; it promotes renal calcium reabsorption, urinary phosphate excretion, renal conversion of vitamin D to its active form, and osteoclastic activity.

Primary Hyperparathyroidism

An autonomous spontaneous overproduction of PTH, usually caused by parathyroid hyperplasia or an adenoma; it is an important cause of hypercalcemia and is seen primarily in adults with a ratio of $4\text{F}:1\text{M}$.

"Painful bones, stones, abdominal groans, and psychic moans"

The classic clinical mnemonic for primary hyperparathyroidism, describing bone fractures from osteoporosis, kidney stones, constipation/peptic ulcers/gallstones, and depression/lethargy/seizures.

Ground Glass Bone Pattern

An altered, diffuse radiographic trabecular bone pattern observed in the jaws of patients with hyperparathyroidism.

Secondary Hyperparathyroidism

Hypersecretion of PTH occurring secondary to chronic renal failure, driven by hyperphosphatemia, impaired renal synthesis of active Vitamin $D_3$, and resulting hypocalcemia.

Renal Osteodystrophy

A bone pathology associated with secondary hyperparathyroidism resulting from chronic renal failure and compensatory parathyroid hormone elevation.

Hypoparathyroidism

An uncommon condition caused by accidental surgical removal during thyroidectomy, congenital absence (DiGeorge Syndrome), or autoimmune destruction; manifests with hypocalcemia, neuromuscular excitability, cardiac arrhythmias, increased intracranial pressure, and seizures.

Islets of Langerhans

Microscopic endocrine cell clusters in the pancreas comprising Beta cells (insulin), Alpha cells (glucagon), Delta cells (somatostatin), and PP cells (VIP, pancreatic polypeptide).

Glucagon

A pancreatic hormone produced by alpha cells that mobilizes liver carbohydrates into circulation by promoting glycogenolysis and gluconeogenesis during fasting states.

Insulin

The major anabolic hormone produced by pancreatic beta cells that promotes glucose uptake, glycogen synthesis, lipogenesis, and protein synthesis while inhibiting gluconeogenesis and lipolysis.

Somatostatin

A hormone produced by pancreatic delta cells that suppresses the release of both insulin and glucagon.

Diabetes Mellitus Diagnostic Criteria

Diagnostic blood findings including a random glycemia $\ge 200\,\text{mg/dL}$ with classic symptoms, fasting blood glucose $\ge 126\,\text{mg/dL}$ on more than one occasion, an abnormal glucose tolerance test, or an $\text{HbA}_{1c} \ge 6.5\%$.

Type 1 Diabetes Mellitus

A chronic autoimmune disease characterized by self-reactive T cell and autoantibody destruction of pancreatic beta cells, causing an absolute deficiency in insulin; typically diagnosed before age $20$ in normal-weight individuals.

Classic Symptoms of Type 1 Diabetes

Polydipsia (increased thirst), polyuria (increased urination frequency/amount), polyphagia (increased hunger), and ketoacidosis, which emerge after $90\%$ of beta cells are destroyed.

Type 2 Diabetes Mellitus

A non-autoimmune metabolic disorder accounting for $\sim 90\%$ of diabetes cases, resulting from peripheral insulin resistance and inadequate compensatory insulin secretion; commonly presents in adults over age $40$ and is associated with obesity in $80\%$ of patients.

Diabetic Vasculopathy

Vascular damage responsible for $80\%$ of diabetes-related deaths, causing atherosclerosis, myocardial infarction, stroke, lower extremity gangrene, and thickened basement membranes around small vessels (microangiopathy).

Kimmelstiel-Wilson Lesion

Nodular glomerulosclerosis characterized by ball-like depositions of matrix at the periphery of renal glomeruli; seen in $15\text{--}30\%$ of long-term diabetic patients and leading to renal failure.

Diabetic Retinopathy

The fourth leading cause of blindness, characterized by retinal microangiopathy, microaneurysms, retinal detachment, and progressive vision loss.

Zollinger-Ellison Syndrome

A condition caused by a gastrin-secreting pancreatic islet cell tumor (gastrinoma) that induces hypersecretion of gastric acid and peptic ulcerations in $90\text{--}95\%$ of patients.

Adrenal Cortex

The outer portion of the adrenal gland that secretes steroid hormones: cortisol/cortisone, aldosterone, estrogen, and progesterone.

Adrenal Medulla

The central portion of the adrenal gland composed of chromaffin cells that synthesize and secrete catecholamines (epinephrine, norepinephrine, dopamine).

Cushing Syndrome

Hypercortisolism caused by exogenous glucocorticoid administration, primary adrenal hyperplasia/adenomas, pituitary ACTH hypersecretion, or ectopic paraneoplastic ACTH production.

Cushing Disease

A specific form of Cushing syndrome caused by primary pituitary ACTH hypersecretion from a pituitary microadenoma.

Moon Facies

A characteristic rounded facial appearance resulting from facial adipose accumulation in patients with Cushing syndrome.

Buffalo Hump

An accumulation of adipose tissue over the posterior neck and upper back, typically seen in Cushing syndrome.

Hyperaldosteronism

Excess chronic aldosterone secretion causing sodium retention, potassium excretion, hypertension, and hypokalemia; classified as primary (decreased plasma renin) or secondary (activation of the renin-angiotensin system with increased renin).

Acute Adrenocortical Insufficiency

A life-threatening adrenal crisis precipitated by rapid withdrawal of exogenous steroids, acute stress without dose escalation, or adrenal hemorrhage; manifests with vomiting, abdominal pain, hypotension, coma, and death.

Addison Disease (Primary Chronic Adrenocortical Insufficiency)

Progressive destruction of the adrenal cortex (requiring $\ge 90\%$ destruction) most commonly due to autoimmune disease, TB, or AIDS; characterized by elevated serum ACTH, hyperpigmentation of skin and oral mucosa, weakness, salt craving, and GI disturbances.

Pheochromocytoma

A surgically correctible neoplasm of chromaffin cells in the adrenal medulla that secretes epinephrine; causes hypertension, tachycardia, tremor, and headache, and predominates in females aged $30\text{--}60$ years.

Rule of 10's (Pheochromocytoma)

A clinical guideline stating that approximately $10\%$ of pheochromocytomas are bilateral, $10\%$ are extra-adrenal, $10\%$ are malignant, and $10\%$ present without hypertension (among familial cases).

Multiple Endocrine Neoplasia (MEN) 1

An inherited endocrine neoplasia syndrome characterized by pituitary adenomas, parathyroid hyperplasia, and pancreatic neuroendocrine tumors.

Multiple Endocrine Neoplasia (MEN) 2A

An inherited tumor syndrome characterized by parathyroid hyperplasia, medullary thyroid carcinoma, and pheochromocytoma.

Multiple Endocrine Neoplasia (MEN) 2B

A syndrome linked to the RET proto-oncogene characterized by mucosal neuromas (tongue, labial commissure, eyelids), Marfanoid body habitus, early-onset medullary thyroid carcinoma, and pheochromocytoma.