Ch 13: Altered Hormones and Metabolic Regulation

What are hormones?

chemicals that effect other organs

What system works in tandem with the endocrine system?

nervous system

What is the function of the endocrine system?

made of glands that secrete hormones directly into the blood stream

Hormones target…

specific organs

What secretes hormones?

glands

actions of hormones

1. control

2. patterns (of metabolism/hormone secretions/eliminiation)

3. action (on specific organs/glands)

4. receptor binding

5. feedback (positive/negative loops)

How are hormones controlled?

via hypothal-pituitary axis

s/s of excess antidiuretic

• fluid retention

• low urine output

• hyponatremia

s/s of antidiuretic deficit

• excess urine output

• nausea vomit fatigue

• dehydration

• shock twitching

s/s of excess glucocorticoids

• truncal obesity

• moon face

• buffalo hump

• poor wound healing

• striae

• osteoporosis

s/s of glucocorticoid deficit

• hypoglycemia

• weight loss

• poor stress response

s/s of excess growth hormone

• gigantism (before puberty)

• acromegaly (post puberty)

• hypertension

s/s of growth hormone deficit

• short stature

• obesity

• seizures in children

• hypoglycemia

• high circulating lipids in adults

s/s of excess aldosterone

• hypernatremia

• hypokalemia

• polyuria/dipsia

• metabolic alkalosis

s/s of aldosterone deficit

• weakness

• hyponatermia

• hyperkalemia

• dehydration

• hypotension and shock

s/s of excess thyroid hormone

• hyper metabolism

• weight loss

• exophthalmos

• goiter

s/s of thyroid hormone

• hypometabolism

• weight gain

• constipation

• goiter

• dry skin/coarse hair

s/s of excessive parathyroid hormone

• hypercalcemia

• excessive osteoclastic activity

• fractures

• formation of renal calculus (kidney stones)

s/s of parathyroid hormone deficit

• hypocalcemia

• muscle spasm

• hyperreflexia

• seizures

• bone deformities

How would you diagnose an altered hormone function?

• serum and urine lab levels

• hormone suppression and simulation tests

• serum electrolyte glucose and calcium levels

• imaging studies

• genetic testing

What does SIADH stand for?

syndrome of inappropriate antidiuretic hormone

What is SIADH?

the excess production/secretion of ADH

What is the most common cause of SIADH?

tumor secreting ectopic ADH

pathophysiology of SIADH

ADH promotes water retention in cells → sodium dilutes in extracellular space → hypotonic hyponatermia

s/s of SIADH

• decreased urine output

• anorexia nausea vomiting headache

• disorientation cramps weakens

• psychosis irregular gait seizures coma

diagnosis of SIADH

• serum sodium levels <135 (hyponatermia)

• plasma osmolality <280 (hypotonicity)

• decreased urine volume

• highly concentrated urine with high sodium

• no renal adrenal or thyroid problems

treatment of SIADH

• remove the tumor

• water restriction

• isotonic/hypertonic IV replacement

What is diabetes insipidus?

insufficent ADH causes inability to concentrate or retain water

What causes diabetes insipidus?

• insufficient ADH production/secretion

• kidney doesn’t respond to ADH

• water intoxication

s/s of diabetes insipidus

• polyuria

• excessive thirst

• dehydration

• shock

• death if untreated

diagnosis of diabetes insipidus

lab tests for

• serum solute concentration

• ADH levels

• urine specific gravity

• urine osmolaty

treatment of diabetes insipidus

• treat cause

• hydration

• desmopressin (antidiuretic)

pathophysiology of hyperthyroidism

excessive thyroid hormone due to the excessive stimulation/disease of thyroid gland or excessive production of TSH

What is the most common cause of hyperthyroidism?

Graves disease

What is Graves disease?

autoimmune disorder where IgG binds to TSH receptors on thyrocytes

s/s of hyperthyroidism

• goiter (enlarged thyroid gland)

• weight loss

• heat intolerance

• tachycardia

• fine hair oily skin

• exophthalmos

diagnosis of hyperthyroidism

• serum TSH T3 and T4 levels

• free thyroxine level

• increased uptake of radioactive iodine

treatment of hyperthyroidism

• meds that block thyroid hormone production

• oral thyroid hormone replacement

• destruction of gland with radioactive iodine

• surgical removal of gland

pathophysiology of hypothyroidism

deficiency of thyroid hormone due to lack of thyroid gland development, not enough TH made, destruction of thyroid gland, or impaired secretion

What can cause hypothyroidism?

• autoimmunity

• genetic defects

• injury to gland

• iodine deficiency

s/s of hypothyroidism

• fatigue weakness lethargy weight gain

• cold intolerance

• constipation

• impaired memory

• myxedema

diagnosis of hypothyroidism

• TSH levels

• total T3 and T4 uptake

• thyroid autoantibodies

• antithyroglobulin levels

treatment of hypothyroidism

lifelong thyroid hormone replacement therapy

what is cushing syndrome?

excess glucocosteriods affects metabolic stress response inflammatory and immune responses

causes of cushing syndrome

• long term administration of exogenous glucocorticoids

• tumors of pituitary gland

• tumors of adrenal gland

• ectopic production of ACTH or CRH from tumor of a distance site

s/s of cushing syndrome

• metabolic alterations

• obesity of trunk face upper back

• glucose intolerance

• suppression of immune response

• behavioral changes

• impaired stress response

diagnosis of cushing syndrome

• cortisol levels in 24 hour urine

• imaging studies to detect tumors

treatment of cushing syndrome

• remove cause of excess cortisol secretion

• gradually taper exogenous glucocorticoid medications

• surgical removal of tumors chemotherapy radiation

What is addison disease?

autoimmune destruction of the adrenal cortex

pathophysiology of addison disease

adrenal glands cannot produce glucocorticoids mineralocorticoids or androgens → ACTH levels increase to stimulate secretions

s/s of addison disease

• darker pigmentation of skin due to high ACTH

• glucocorticoid deficiency

  • hypoglycemia

  • weakness

  • poor stress response

  • weight loss

• mineralocorticoid deficiency

  • dehydration

  • hyponatremia

  • hyperkalemia

  • weakness

diagnosis of addison disease

• hyponatremia

• hyperkalemia

• serum corticosteroid levels remain depressed even after administering ACTH

treatment of addison disease

• fluid replacement

• hydrocortisone

• oral glucocorticoid and mineralocorticoid replacement

• increased sodium intake due to excess sodium losses