CH 10- Endocrine System and Adrenal/Pituitary/Thyroid Disorders

Comprehensive vocabulary flashcards covering the anatomy, physiology, and pathology of the endocrine system including the pituitary, thyroid, parathyroid, and adrenal glands, as well as diabetes mellitus.

Endocrine System

A network of glands and hormone-secreting tissues that regulates long-term physiological processes by releasing biochemical signaling molecules directly into the bloodstream.

Hormones

Biochemical signaling molecules secreted by endocrine glands that travel through the bloodstream to bind to specific receptors on target cells and alter cellular activity.

Steroid Hormones

Hormones derived from cholesterol characterized by effects that are slow in onset but long-lasting.

Peptide and Protein Hormones

Hormones made of amino acids, such as insulin, glucagon, and growth hormone (GH), which produce rapid but short-lived effects.

Hypothalamus

The link between the nervous and endocrine systems that produces releasing and inhibiting hormones to control the pituitary gland.

Pituitary Gland

Known as the master gland, it regulates other endocrine glands and consists of an anterior lobe secreting trophic hormones and a posterior lobe releasing ADH and oxytocin.

Thyroid Gland

A butterfly-shaped gland in the anterior neck that produces $T_4$ and $T_3$ to regulate metabolic rate, heat production, and growth.

Parathyroid Glands

Four small glands located posterior to the thyroid that secrete parathyroid hormone (PTH) to regulate calcium and phosphate balance.

Aldosterone

A mineralocorticoid produced by the adrenal cortex that increases sodium and water reabsorption and potassium excretion in the kidneys to maintain blood pressure.

Cortisol

A glucocorticoid produced by the adrenal cortex that increases blood glucose via gluconeogenesis and is essential for the long-term stress response.

Epinephrine and Norepinephrine

Catecholamines produced by the adrenal medulla that mediate the rapid, short-lived fight-or-flight response.

Negative Feedback

The most common regulatory mechanism where rising hormone levels inhibit further release to maintain homeostasis.

Positive Feedback

A rare regulatory mechanism where hormone release amplifies further secretion, such as oxytocin release during labor.

Cushing Syndrome

The clinical effects resulting from chronic excess cortisol (hypercortisolism) from any cause, characterized by truncal obesity, moon face, and buffalo hump.

Cushing Disease

A subset of Cushing syndrome specifically caused by a pituitary adenoma secreting excess ACTH.

Primary Aldosteronism (Conn Syndrome)

An adrenal gland disorder, often caused by an adenoma, characterized by high aldosterone levels and low renin levels.

Secondary Aldosteronism

Aldosterone excess due to increased RAAS activation, tied to conditions like renal artery stenosis, heart failure, or cirrhosis.

Congenital Adrenal Hyperplasia (CAH)

A group of inherited disorders, most commonly 21-hydroxylase deficiency, leading to excess androgen production and deficient cortisol.

Addison Disease

Primary adrenal insufficiency caused by the destruction of the adrenal cortex, resulting in low cortisol, low aldosterone, and elevated ACTH levels.

Addisonian Crisis

A medical emergency precipitated by stress in patients with hypoadrenalism, characterized by severe hypotension, hypoglycemia, and hyperkalemia.

Adrenocortical Carcinoma (ACC)

A rare, aggressive malignant tumor of the adrenal cortex that may be functional (hormone-secreting) or nonfunctional.

Pheochromocytoma

A rare benign catecholamine-secreting tumor arising from chromaffin cells of the adrenal medulla, presenting with a triad of headache, sweating, and palpitations.

Neuroblastoma

A malignant tumor of the adrenal medulla and the most common extracranial solid tumor in childhood, often occurring in children under age 2.

Growth Hormone (Somatotropin)

An anterior pituitary hormone that promotes tissue growth, increases protein synthesis, and stimulates long bone growth before puberty.

Prolactin (PRL)

A hormone secreted by the anterior pituitary that stimulates milk production and is primarily inhibited by dopamine.

Diabetes Insipidus (DI)

A disorder of water balance characterized by polyuria and polydipsia due to deficient ADH action or renal resistance to ADH.

Graves Disease

The most common cause of hyperthyroidism; an autoimmune disorder where thyroid-stimulating immunoglobulins (TSI) activate TSH receptors.

Hashimoto Thyroiditis

The most common cause of hypothyroidism in developed countries, characterized by autoimmune destruction of thyroid tissue.

Cretinism

A clinical term for severe congenital hypothyroidism present at birth which leads to permanent physical and intellectual impairment if untreated.

Goiter

A physical finding describing the enlargement of the thyroid gland, which can be associated with hyperthyroidism, hypothyroidism, or euthyroidism.

Papillary Thyroid Carcinoma

The most common type of thyroid cancer, which is typically slow-growing and has an excellent prognosis.

Anaplastic Thyroid Carcinoma

A rare but highly aggressive malignant thyroid tumor occurring in older adults with a very poor prognosis.

Parathyroid Hormone (PTH)

The main regulator of serum $Ca^{2+}$ levels that increases blood calcium by acting on bone, kidneys, and indirectly on the GI tract.

Primary Hyperparathyroidism

Autonomous overproduction of PTH, most commonly by a parathyroid adenoma, leading to hypercalcemia and hypophosphatemia.

Pseudohypoparathyroidism (PHP)

A genetic disorder characterized by end-organ resistance to PTH, resulting in hypocalcemia and hyperphosphatemia despite normal or high PTH levels.

Albright Hereditary Osteodystrophy (AHO)

A genetic syndrome featuring short stature, round face, and shortened 4th and 5th metacarpals, often associated with pseudohypoparathyroidism.

Diabetes Mellitus (DM)

A chronic metabolic disorder characterized by hyperglycemia caused by insufficient insulin production, impaired insulin action, or both.

Type 1 Diabetes Mellitus (T1DM)

An autoimmune destruction of pancreatic $\beta$-cells leading to absolute insulin deficiency, usually presenting in children or young adults.

Type 2 Diabetes Mellitus (T2DM)

The most common form of diabetes, characterized by insulin resistance and relative insulin deficiency, strongly associated with obesity.