ENDOCRINE EXAM 3 PATHO PT2

What is hypothyroidism?

A condition characterized by deficient production of thyroid hormones (T3 and T4) by the thyroid gland.

What causes primary hypothyroidism?

A problem in the thyroid gland itself, leading to decreased hormone production.

What causes secondary hypothyroidism?

A problem in the pituitary gland, which fails to produce enough TSH to stimulate the thyroid.

What are some manifestations of hypothyroidism?

Decreased metabolic rate, cold intolerance, decreased heat production, lethargy, myxedema, thin hair, and hoarseness.

What is myxedema?

A severe form of hypothyroidism characterized by thickened, swollen skin and symptoms like fatigue, weight gain, and cold intolerance.

What is myxedema coma?

A rare, life-threatening complication of untreated or poorly managed hypothyroidism, marked by extreme drowsiness, low body temperature, slowed breathing, and possible unconsciousness.

What is required for myxedema coma?

Emergency medical treatment.

What is Graves' disease?

An autoimmune disorder that causes hyperthyroidism.

What is hyperthyroidism resulting from nodular thyroid disease?

A condition where the thyroid produces excess hormones due to nodules.

What is a thyrotoxic crisis?

A severe form of hyperthyroidism that can be fatal and is often associated with physiologic stress or sepsis.

What happens to TH levels during a thyrotoxic crisis?

TH levels rise dramatically.

Hashimoto disease (autoimmune thyroiditis)

antibodies trigger lymphocytes to destroy follicular cells in the thyroid gland, producing hypothyroidism

congenital hypothyroidism

condition present at birth that results in lack of thyroid hormones; results in poor physical and mental development; formerly called cretinism

Subacute thyroiditis (de Quervain's)

Self limited hypothyroidism after flulike illness. Granulomatous inflammation w/ elevated ESR. Very tender.

Postpartum thyroiditis

inflammation of the thyroid gland following childbirth

Latrogenic Hypothyroidism

induced by thyrotoxicosis treatment or surgery

manifestations of hypothyroidism

Mental and physical sluggishness

Myxedema

Somnolence

Decreased cardiac output, bradycardia

Constipation

Decreased appetite

Hypoventilation

Cold intolerance

Coarse dry skin and hair

Weight gain

manifestations of hyperthyroidism

Thyroid storm

Restlessness, irritability, anxiety

Wakefulness

Increased cardiac output

Tachycardia and palpitations

Diarrhea, increased appetite

Dyspnea

Heat intolerance, increased sweating

Thin and silky skin and hair

Weight loss

What are the parathyroid glands?

Small paired parathyroid glands

What hormone do the parathyroid glands secrete?

Parathyroid hormone (PTH)

What effect does PTH secretion have on ionized calcium levels?

Increases levels of ionized calcium in the plasma

What effect does PTH secretion have on phosphate levels?

Decreases levels of phosphate in the plasma

What is hyperparathyroidism?

Increased secretion of parathyroid hormone (PTH)

What are the classifications of hyperparathyroidism?

Primary, Secondary, Tertiary

What is primary hyperparathyroidism?

Excess secretion of PTH from one or more parathyroid glands

What is secondary hyperparathyroidism?

Increase in PTH secondary to chronic hypocalcemia

What is tertiary hyperparathyroidism?

Develops after a long period of hypocalcemia

What are the effects of hyperparathyroidism?

Leads to neuromuscular symptoms, bone damage, and renal stones

What is hypoparathyroidism?

Abnormally low PTH levels

What are the consequences of hypoparathyroidism?

Causes hypocalcemia, hyperphosphatemia, and decreased bone resorption

What triggers the release of PTH?

When calcium levels fall

What type of gland is the pancreas?

The pancreas is both an endocrine and an exocrine gland.

What are the islets of Langerhans composed of?

The islets of Langerhans consist of alpha cells, beta cells, delta cells, and F cells.

What do alpha cells in the pancreas produce?

Alpha cells produce glucagon.

How is glucagon secreted in relation to blood glucose concentrations?

Glucagon is secreted inversely to blood glucose concentrations.

What is the function of glucagon?

Glucagon helps increase blood glucose levels.

What do beta cells in the endocrine pancreas synthesize?

Insulin and amylin

What hormone is secreted by beta cells?

Insulin

What is amylin?

A hormone secreted by beta cells along with insulin

What do delta cells secrete?

Somatostatin

What is the function of somatostatin?

It inhibits glucagon and insulin secretion

What do F cells secrete?

Pancreatic polypeptide

What is the function of pancreatic polypeptide?

It inhibits gallbladder contraction and exocrine pancreatic secretion

Where are the adrenal glands located?

Close to the upper pole of each kidney

What are the two portions of the adrenal glands?

Outer adrenal cortex and inner adrenal medulla

What type of hormones are secreted by the adrenal cortex?

Steroid hormones

From what are the steroid hormones secreted by the adrenal cortex synthesized?

Cholesterol

What are glucocorticoids?

Hormones that affect carbohydrate metabolism by increasing blood glucose concentration through gluconeogenesis in the liver and by decreasing uptake of glucose.

What is the most potent naturally occurring glucocorticoid?

Cortisol

Why is cortisol important?

It is needed for the maintenance of life and for protection from stress.

What do mineralocorticoids affect?

Ion transport in epithelial cells, causing sodium retention and potassium and hydrogen loss.

What is the most potent naturally occurring mineralocorticoid?

Aldosterone

What is the primary role of aldosterone?

To increase blood pressure and intravascular volume.

Where is the principal site of aldosterone action?

Epithelial cells involved in ion transport.

What is Cushing syndrome?

A disorder characterized by chronic excess cortisol, regardless of cause.

What are common manifestations of Cushing syndrome?

Hypertension, fatigue, edema, 'buffalo hump', truncal obesity, and abdominal purple striae.

What is Cushing disease?

A condition caused by excessive anterior pituitary secretion of ACTH.

Is Cushing disease common or rare?

Very rare.

What happens if the negative feedback loop is effective in Cushing disease?

The pituitary gland will produce less ACTH.

What causes hyperaldosteronism?

Excessive aldosterone secretion

What effect does hyperaldosteronism have on sodium reabsorption?

It promotes increased sodium reabsorption

What is a consequence of increased sodium reabsorption in hyperaldosteronism?

Hypervolemia

How does hyperaldosteronism affect extracellular volume?

It increases extracellular volume, which is variable

What electrolyte imbalance is associated with hyperaldosteronism?

Hypokalemia

Why does hypokalemia occur in hyperaldosteronism?

Due to renal reabsorption of sodium and excretion of potassium

Primary hyperaldosteronism (Conn syndrome)

Increased aldosterone secretion from abnormality in adrenal cortex

Secondary hyperaldosteronism

Aldosterone release due to activation of renin-angiotensin system

manifestations of hyperaldosteronism

hypertension and hypokalemia

What is primary adrenal insufficiency also known as?

Addison disease

What is the treatment for Addison disease?

Lifelong corticosteroid replacement

What mechanism primarily causes Addison disease?

Autoimmune mechanisms destroy adrenal cortical cells

What is an Addisonian crisis?

Hypotension leading to vascular collapse and shock

What characterizes Addison disease in terms of hormone levels?

Elevated ACTH levels with inadequate corticosteroid and mineralocorticoid synthesis

What triggers the release of corticosteroids from the adrenal cortex?

The hypothalamus-pituitary-adrenal system in response to ACTH

What are the typical blood levels in Addison disease?

Low blood glucose levels and high potassium

What is secondary hypocortisolism characterized by?

Decreased ACTH and adrenal atrophy

What can cause decreased ACTH secretion?

Pituitary infarction, pituitary tumors, or hypophysectomy

What happens to adrenal steroidogenesis in secondary hypocortisolism?

It is depressed due to low ACTH levels and adrenal atrophy

What is metabolic syndrome?

Metabolic syndrome is diagnosed when someone has three or more specific risk factors.

What is one risk factor for metabolic syndrome related to blood glucose?

High blood glucose

What is one risk factor for metabolic syndrome related to cholesterol levels?

Low levels of HDL cholesterol

What is one risk factor for metabolic syndrome related to triglycerides?

High levels of triglycerides

What body shape is associated with a risk factor for metabolic syndrome?

Large waist circumference or 'apple-shaped' body

What does HTN stand for in the context of metabolic syndrome?

Hypertension