Advanced Pathophysiology – Endocrine System Review (Week 9)

Flashcards cover pituitary anatomy, hormone pathways, thyroid and parathyroid disorders, SIADH/DI, stress response, adrenal diseases, and diabetes—including key labs, pathophysiology, and clinical manifestations for advanced practice review.

Which two lobes make up the pituitary gland and which produces most hormones?

The pituitary has anterior and posterior lobes; the anterior pituitary produces most of the body’s hormones.

Name the two key hormones released by the posterior pituitary.

Antidiuretic hormone (ADH/vasopressin) and oxytocin.

What hormone does the anterior pituitary release to stimulate the thyroid?

Thyroid-stimulating hormone (TSH).

Which anterior-pituitary hormone stimulates cortisol release from the adrenal cortex?

Adrenocorticotropic hormone (ACTH).

A patient has low TSH and high free T4. What thyroid disorder does this indicate?

Primary hyperthyroidism (e.g., Graves disease).

Why is TSH elevated in primary hypothyroidism?

The pituitary senses low circulating T4/T3 and increases TSH in an attempt to stimulate a failing thyroid gland.

List three common clinical signs of hypothyroidism.

Fatigue/sluggishness, cold intolerance, constipation (others include bradycardia, weight gain, facial edema).

What life-threatening complication can arise from severe untreated hypothyroidism?

Myxedema coma (hypotension, hypothermia, respiratory depression, coma).

Which disorder involves excess thyroid hormone and classically shows weight loss, heat intolerance, and exophthalmos?

Hyperthyroidism (often Graves disease).

What two hormones control calcium homeostasis via the parathyroid–renal–bone axis?

Parathyroid hormone (PTH) and vitamin D.

How does PTH raise serum calcium?

Stimulates osteoclasts to resorb bone, increases renal calcium reabsorption, and activates vitamin D to enhance GI absorption.

List two classic physical exam signs of hypocalcemia due to hypoparathyroidism.

Chvostek sign (facial twitch) and Trousseau sign (carpal spasm with BP cuff).

Which electrolyte imbalance often accompanies hyperparathyroidism?

Hypercalcemia (with hypophosphatemia).

Define panhypopituitarism.

Deficiency of all anterior pituitary hormones, often due to pituitary agenesis or destructive lesions.

Differentiate gigantism from acromegaly in terms of epiphyseal plate status.

Gigantism occurs before epiphyseal plates close (extreme height); acromegaly occurs after closure (enlarged hands, jaw, soft tissue).

What is the first-line long-term treatment for primary hypothyroidism?

Levothyroxine (synthetic T4) started low and titrated slowly.

SIADH causes what change in serum sodium and urinary output?

Hyponatremia with very low urine output/high urine osmolality (water retention).

Diabetes insipidus leads to which three hallmark findings?

Polyuria, polydipsia, hypernatremia (due to ADH deficiency or resistance).

Name the three “polys” of diabetes mellitus.

Polyuria, polydipsia, polyphagia.

Differentiate type 1 and type 2 diabetes in terms of insulin status.

Type 1: absolute insulin deficiency; Type 2: insulin resistance with normal or high endogenous insulin initially.

What acid–base disorder characterizes diabetic ketoacidosis (DKA)?

High-anion-gap metabolic acidosis with serum/urine ketones.

Typical plasma glucose level comparison: Which is higher, DKA or HHS?

Hyperosmolar hyperglycemic state (HHS) usually has higher glucose (>600 mg/dL) than DKA.

Which adrenal cortex disorder results from chronic excess glucocorticoids?

Cushing syndrome.

List two hallmark physical features of Cushing syndrome.

Truncal obesity with thin extremities and ‘moon face’ (others: buffalo hump, purple striae).

A tumor of the adrenal medulla causing paroxysmal hypertension and tachycardia is called what?

Pheochromocytoma (excess epi/norepi).

Addison disease results in deficiency of which key hormone and what classic presentation during stress?

Low cortisol; presents with hypotension and hypoglycemia during stress (Addisonian crisis).

What triggers renin release in the kidney, initiating the stress (HPA) axis?

Decreased renal perfusion pressure or sympathetic stimulation.

Which stress hormone is released from the adrenal medulla during the alarm phase?

Epinephrine (and norepinephrine).

How does aging affect thyroid function tests in many individuals?

T4 production decreases but clearance slows; TSH may rise slightly, making interpretation tricky in elders.

Name two causes of hyperprolactinemia and one key clinical sign.

Pituitary adenoma or antipsychotic medications; sign: galactorrhea with menstrual dysfunction.

Why can chronic kidney disease lead to secondary hyperparathyroidism?

Impaired vitamin D activation and calcium reabsorption cause hypocalcemia, stimulating continuous PTH release and parathyroid hyperplasia.

What electrolyte must often be corrected before calcium will rise during replacement therapy?

Magnesium (hypomagnesemia impairs PTH secretion and calcium uptake).

Which hormones have a negative feedback loop but are exceptions within the endocrine system?

Most (e.g., thyroid, cortisol) use negative feedback, but some (e.g., oxytocin during labor) operate via positive feedback.

Give one airway concern in a patient with long-standing acromegaly.

Difficult airway/intubation due to enlarged jaw, tongue, and soft-tissue hypertrophy.

What are the three primary target tissues/organs for insulin?

Liver, muscle, and adipose tissue.