Endocrine system and metabolic disorders lecture Review

A comprehensive set of vocabulary flashcards covering the endocrine system, pituitary disorders, adrenal conditions, thyroid/parathyroid diseases, and diabetes mellitus based on the lecture transcript.

Endocrine system

A system that integrates body functions by the synthesis and release of hormones, linked to the nervous system via the hypothalamus.

Endocrine Glands

Glands that secrete their products directly into the bloodstream without using ducts.

Exocrine glands

Glands that secrete through ducts onto epithelial surfaces or into the gastrointestinal tract.

Hormone

Chemical substances secreted by endocrine glands that act only on cells or tissues with specific receptors.

Target Organ

The specific cell or tissue that responds to a particular hormone.

Negative Feedback Mechanism

A regulatory system where hormone production is inhibited when concentrations rise and increased when concentrations fall to maintain a constant level.

Primary disease

An autonomous problem located within the target gland itself.

Secondary disease

A problem located outside the target gland, most often due to an issue in the pituitary gland.

Hypopituitarism

A condition caused by low levels of one or more anterior pituitary hormones, leading to a loss of function in the gland or organ it controls.

Sheehan syndrome

A cause of primary hypopituitarism resulting from an inadequate blood supply to the pituitary gland.

Bitemporal hemianopia

A visual field defect, often caused by a pituitary tumor, identified on visual confrontation.

Gonadotropin Deficiency

A deficiency that may cause delayed secondary sexual characteristics, micropenis, or cryptorchidism if congenital, or loss of body hair and infertility if acquired.

failure to lactate

A specific sign of Prolactin Deficiency.

Growth hormone (GH) deficiency

In childhood, this leads to a failure to grow; in adulthood, it causes central obesity, increased systolic blood pressure, and increased LDL cholesterol.

Transsphenoidal hypophysectomy

A surgical procedure for removing pituitary tumors via an endoscopic, transnasal approach.

Hyperpituitarism

The over-secretion of one or more anterior pituitary hormones, usually caused by a benign pituitary adenoma.

Gigantism

Hypersecretion of Growth Hormone (GH) prior to the closure of epiphyses, resulting in proportional growth.

Acromegaly

Hypersecretion of Growth Hormone (GH) after the closure of epiphyses, resulting in disproportional growth and coarsening of facial features.

Macroglossia

Enlargement of the tongue, a common symptom in patients with acromegaly.

Halo ring

A sign of a cerebrospinal fluid (CSF) leak on gauze during postoperative care following pituitary surgery.

Diabetes Insipidus (DI)

A disorder characterized by massive polyuria and intense thirst due to a lack of ADH (Vasopressin) or the kidney's insensitivity to it.

Central Diabetes Insipidus

A deficiency of vasopressin that can be primary (familial/idiopathic) or secondary (due to damage from tumors, trauma, or infection).

Nephrogenic Diabetes Insipidus

A condition where the kidney tubules are unresponsive to vasopressin, despite normal secretion levels.

DI urine specific gravity

A range between $1.001$ and $1.005$ indicating very dilute, water-like urine.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

A disorder characterized by excessive ADH release, leading to concentrated urine excretion and hyponatremia without edema.

SIADH hyponatremia threshold

Serum sodium level falling below $135\,meq/L$ (often reaching below $120\,meq/L$ in severe cases).

Glucocorticoids

Adrenal cortex hormones such as Cortisol and Corticosterone that increase blood glucose via gluconeogenesis.

Mineralocorticoids

Adrenal cortex hormones like Aldosterone that regulate fluid and electrolyte balance by stimulating sodium reabsorption and potassium excretion.

Adrenal Medulla

The part of the adrenal gland that releases catecholamines (Epinephrine and Norepinephrine) during "fight or flight" situations.

Cushing's Syndrome

A cluster of physical abnormalities (such as moon face and buffalo hump) caused by excessive cortisol release or exogenous steroid therapy.

Dexamethasone Suppression Test

A diagnostic test where $1\,mg$ of dexamethasone is given at $11\,PM$ and serum cortisol is measured at $8\,AM$ to exclude Cushing's syndrome.

Primary hyperaldosteronism

Also known as Conn's syndrome, involving autonomous secretion of aldosterone from a benign adrenal adenoma.

Addison's disease

The most common form of primary adrenal hypofunction, often an autoimmune process leading to decreased secretion of androgens, glucocorticoids, and mineralocorticoids.

Adrenal Crisis

A medical emergency characterized by profound weakness, shock, hypotension, and high fever caused by exhausted glucocorticoid stores.

Pheochromocytoma

A rare chromaffin-cell tumor of the sympathetic nervous system, usually in the adrenal medulla, that secretes excess catecholamines.

Vanilylmandelic acid (VMA)

An elevated urinary substance used to diagnose Pheochromocytoma; patients must avoid coffee, nuts, chocolate, and bananas prior to testing.

Thyroxine (T4)

A thyroid hormone produced to maintain body metabolism in a steady state.

Triiodothyronine (T3)

A thyroid hormone approximately five times as potent as T4 with a more rapid metabolic action.

Thyroid-Stimulating Hormone (TSH)

The single best screening test for thyroid function with a normal range of $0.38$ to $6.15\,uU/mL$.

Grave's disease

An autoimmune form of hyperthyroidism characterized by thyrotoxicosis, exophthalmos, and pretibial myxedema.

Thyroid Storm

A high-mortality medical emergency featuring delirium, severe tachycardia, and high fever due to severe hypermetabolism.

Propylthiouracil (PTU)

The preferred antithyroid medication for use during pregnancy to treat hyperthyroidism.

Myxedema Coma

A severe state of hypothyroidism manifesting as hypotension, bradycardia, hypothermia, and respiratory failure.

Chvostek's sign

A positive sign for neuromuscular irritability (hypocalcemia) involving facial muscle twitching.

Trousseau's sign

A positive sign for hypocalcemia involving carpal spasms induced by a blood pressure cuff.

Diabetes Mellitus

A chronic disease characterized by hyperglycemia due to insulin deficiency or cell insensitivity.

Glycosylated hemoglobin (HbA1c)

A lab value where $7.5\%$ or less indicates good control of blood sugar over time.

Dawn phenomenon

An increase in blood sugar at around $3\,AM$ caused by the release of growth hormone.

Somogyi effect

Rebound hyperglycemia at $7\,AM$ following a bout of hypoglycemia at $2-3\,AM$.

DKA (Diabetic Ketoacidosis)

An acute complication of Type 1 DM characterized by hyperglycemia and metabolic acidosis from ketone accumulation.

HHNK (Hyperglycemic Hyperosmolar Nonketotic Coma)

A hyperosmolar state without ketosis that typically occurs in elderly patients with Type 2 DM.