Chap 40 Endocrine Disorders

Flashcards covering the mechanisms, etiology, classification, and specific instances of endocrine disorders, including GH imbalance, thyroid dysfunction, and adrenal disorders.

Congenital Etiology of Endocrine Disorders

An inborn genetic defect that causes excessive production of hormone precursors.

Autoimmune Etiology of Endocrine Disorders

Genetic predisposition and environmental trigger where antibodies are made against antigens on gland cells.

Neoplastic Etiology of Endocrine Disorders

Hormones produced by abnormal tissue sites (ectopic) such as malignancies.

Functional Disorders of Endocrine Disorders

Endocrine disorders caused by nonendocrine disease such as chronic renal failure, liver disease, or heart failure.

Tissue Resistance of Endocrine Disorders

Occurs when target tissue fails to respond to a hormone; clinically similar to hyposecretion.

Iatrogenic Etiology of Endocrine Disorders

Endocrine disorders induced by medical treatments (chemotherapy, radiation) or surgical removal of glands.

Primary Endocrine Disorders

Intrinsic malfunction of the hormone-producing gland which DECREASE levels of circulating hormone and INCREASE pituitary hormone.

Secondary Endocrine Disorders

Abnormal pituitary secretion of trophic signals which decreases levels of circulating hormone and abnormal pituitary hormone secretion.

Growth Hormone Deficiency Etio + Diagnosis/Treatment

Etio: congenital, tumors, trauma, radiation

Diagnosis: decreased serum GH levels, decreased GH response to stimulation tests (insulin, arginine, and clonidine)

Treatment: GH replacement therapy-> effective only if epiphyseal plates not fused (children)

Growth Hormone Deficiency S/S (Children vs. Adults)

Infants (normal birth weight + length); Children present with short stature, delayed puberty, and bone age; adults present with decreased lean body mass and bone density, and increased cholesterol.

Gigantism

Excess Growth Hormone (GH) occurring BEFORE puberty.

Acromegaly

Excess GH after puberty caused by a benign pituitary tumor (increased GH and IGF-1), featuring increased ring/shoe size, mandible growth, coarse facial features, and increased internal organ size.

Octreotide

A treatment used to counteract the effects of excess Growth Hormone (GH).

Graves Disease

An autoimmune form of primary hyperthyroidism where TSH receptor antibodies increase $T_3$ and $T_4$ levels.

Secondary Hyperthyroidism

Hypersecretion of TSH due to a pituitary tumor, which increases $T_3$ and $T_4$ levels.

Hyperthyroidism Pathophysiology

Autoantibodies stimulate TSH receptors, causing excess thyroid hormone production, increased SNS activity, and a hypermetabolic state.

S/S of Hyperthyroidism

Hypermetabolism (weight loss + heat intolerance), Toxic goiter (enlarged thyroid), Exophthalmos (increased orbital tissue -> mass protruding eyes), Cardiac (tachycardia, palpitations), Neurologic (anxiety + tremors)

Exophthalmos

Increased orbital tissue causing mass protruding eyes; a clinical manifestation of hyperthyroidism.

Thyroid Storm (Thyrotoxic Crisis)

A life-threatening emergency triggered by infection or surgery, presenting with hyperthermia, severe tachycardia + HF, and delirium

Treatment: radioactive iodine, antithyroid drugs, thyroidectomy (risk of hypothyroidism)

Hypothyroidism

A condition resulting in decreased metabolism of ALL cells.

Mild Hypothyroidism

common; easily treated with thyroid hormone replacement

Hashimoto’s Thyroiditis

Autoimmune destruction of the thyroid; recognized as the MOST COMMON CAUSE of severe hypothyroidism.

Myxedema

A state of severe hypothyroidism characterized by nonpitting edema, facial puffiness, and a thick tongue.

Diagnostic Tests for Thyroid Disorders

T3 + T4 = Measure thyroid hormone; TSH (assess pituitary response); Radioactive iodine uptake (evaluate gland activity); Thyroid Scan (detect nodules); Antibody assays (Confirm autoimmune disease)

Cushing’s Syndrome Etio + S/S

Caused by hypercortisolism from excess glucocorticoids; S/S include moon face/buffalo hump, limb muscle wasting, striae, hirsutism, and risk of infections. Etio: adrenal adenoma, pituitary adenoma (cushing DISEASE), ectopic carcinoma, iatrogenic

Cushing DISEASE

Hypercortisolism specifically caused by a pituitary adenoma.

Pheochromocytoma

A benign tumor of the adrenal medulla that increases epi and norepi, causing headache, palpitations, sweating, and anxiety. treatment→ surgery

Addison’s Disease

Adrenal insufficiency caused by autoimmune destruction (most common), infection (TB, fungal, viral), or tumors; leads to deficiency of glucocorticoids, mineralocorticoids, and androgens.

Addison’s Disease (Clinical Manifestations)

Includes hypoglycemia/fatigue (decreased cortisol), hyponatremia/hypotension (decreased aldosterone), arrhythmias (increased potassium), hyperpigmentation (decreased ACTH), and body hair loss (decreased androgens).